1
|
Koutsoyiannis D. Stochastic assessment of temperature-CO2 causal relationship in climate from the Phanerozoic through modern times. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2024; 21:6560-6602. [PMID: 39176409 DOI: 10.3934/mbe.2024287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
As a result of recent research, a new stochastic methodology of assessing causality was developed. Its application to instrumental measurements of temperature (T) and atmospheric carbon dioxide concentration ([CO2]) over the last seven decades provided evidence for a unidirectional, potentially causal link between T as the cause and [CO2] as the effect. Here, I refine and extend this methodology and apply it to both paleoclimatic proxy data and instrumental data of T and [CO2]. Several proxy series, extending over the Phanerozoic or parts of it, gradually improving in accuracy and temporal resolution up to the modern period of accurate records, are compiled, paired, and analyzed. The extensive analyses made converge to the single inference that change in temperature leads, and that in carbon dioxide concentration lags. This conclusion is valid for both proxy and instrumental data in all time scales and time spans. The time scales examined begin from annual and decadal for the modern period (instrumental data) and the last two millennia (proxy data), and reach one million years for the most sparse time series for the Phanerozoic. The type of causality appears to be unidirectional, T→[CO2], as in earlier studies. The time lags found depend on the time span and time scale and are of the same order of magnitude as the latter. These results contradict the conventional wisdom, according to which the temperature rise is caused by [CO2] increase.
Collapse
Affiliation(s)
- Demetris Koutsoyiannis
- Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, Zographou, Greece
| |
Collapse
|
2
|
Lapointe F, Karmalkar AV, Bradley RS, Retelle MJ, Wang F. Climate extremes in Svalbard over the last two millennia are linked to atmospheric blocking. Nat Commun 2024; 15:4432. [PMID: 38830858 PMCID: PMC11148056 DOI: 10.1038/s41467-024-48603-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 05/07/2024] [Indexed: 06/05/2024] Open
Abstract
Arctic precipitation in the form of rain is forecast to become more prevalent in a warmer world but with seasonal and interannual changes modulated by natural modes of variability. Experiencing rapid hydroclimatic changes in the Arctic, Svalbard serves as an ideal study location due to its exposure to oceanic and atmospheric variability in the North Atlantic region. Here we use climate data from paleoproxies, observations, and a climate model to demonstrate that wet and warm extremes in Svalbard over the last two millennia are linked to the presence of atmospheric blocking regimes over Scandinavia and the Ural mountain region. Rainfall episodes lead to the deposition of coarse sediment particles and high levels of calcium in Linnévatnet, a lake in southwest Svalbard, with the coarsest sediments consistently deposited during atmospheric blocking events. A unique annually resolved sediment record from Linnévatnet confirms that this linkage has been persistent over the past 2000 years. Our record also shows that a millennial-scale decline in Svalbard precipitation ended around the middle of the 19th century, followed by several unprecedented extreme events in recent years. As warming continues and sea ice recedes, future Svalbard floods will become more intense during episodes of Scandinavian and Ural blocking.
Collapse
Affiliation(s)
- Francois Lapointe
- Department of Earth, Geographic and Climate Sciences, University of Massachusetts, Amherst, MA, USA.
- World Climate Research Programme - Climate and Cryosphere (CliC) Project, University of Massachusetts, Amherst, MA, USA.
| | | | - Raymond S Bradley
- Department of Earth, Geographic and Climate Sciences, University of Massachusetts, Amherst, MA, USA
- World Climate Research Programme - Climate and Cryosphere (CliC) Project, University of Massachusetts, Amherst, MA, USA
| | - Michael J Retelle
- Earth and Climate Sciences, Bates College, Lewiston, ME, USA
- Department of Geology, The University Center in Svalbard, Svalbard, Norway
| | - Feng Wang
- Institut National de la recherche scientifique, University of Québec, Québec, QC, Canada
| |
Collapse
|
3
|
Garcés‐Pastor S, Fletcher WJ, Ryan PA. Ecological impacts of the industrial revolution in a lowland raised peat bog near Manchester, NW England. Ecol Evol 2023; 13:e9807. [PMID: 36818526 PMCID: PMC9926178 DOI: 10.1002/ece3.9807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 02/16/2023] Open
Abstract
(1) Ombrotrophic peat bogs provide valuable records of environmental change on long timescales but are rarely preserved near the major centers of industrial activity. Holcroft Moss is a rare example of a stratigraphically intact lowland peat bog in NW England, which provides a valuable opportunity to trace industrial impacts on vegetation in a sensitive environmental archive close to the early industrializing cities of Manchester and Liverpool. (2) We reconstructed environmental changes at Holcroft Moss before and after the Industrial Revolution using a decadal-scale record of pollen, non-pollen palynomorphs, microcharcoal, peat composition (organic content and ash-free bulk density) and heavy metal content, constrained by a radiocarbon and SCP (spheroidal carbonaceous particle) chronology. We examine the relationship between abiotic and biotic environmental tracers using principal component analysis and evaluate the role of local and regional climatic and anthropogenic drivers using canonical redundancy analysis and partitioning of variation. (3) Results show significant changes in bog vegetation composition during the last 700 years. Prior to 1750 CE, climate and agro-pastoral activity (grazing and fires) were the main drivers of vegetation change. Subsequently, regional coal-fired industry contributed to major increases in atmospheric pollutants (dust, heavy metals, and acid deposition) that severely impacted vegetation, driving the decline of Sphagnum. Grasses rose to dominance in the 20th century associated especially with bog conversion and cumulative nitrogen deposition. Although atmospheric pollution significantly decreased in the post-industrial era, vegetation has not returned to pre-industrial conditions, reflecting the ongoing impact of global change drivers which pose challenges for conservation and restoration. (4) Synthesis. Paleoecological studies are needed to reveal the long-term history of vegetation degradation and to offer guidelines for restoration and conservation practices. This study reconstructs the last 700 years of a peat bog located between Manchester and Liverpool, revealing the timing and nature of vegetation changes across the trajectory of early industrialization and eventual post-industrial decline. Our study reveals the progressive dominance of regional anthropogenic forcing and highlights that the present-day vegetation does not have past analogs within the last 700 years. Conservation measures favoring the reintroduction of Sphagnum are justified in redressing the major biological legacy of the Industrial Revolution, while steps to increase Calluna should also be considered in light of its resilience to dry and fire-prone conditions.
Collapse
Affiliation(s)
- Sandra Garcés‐Pastor
- Quaternary Environments and Geoarchaeology Research Group, Department of Geography, School of Environment, Education and DevelopmentUniversity of ManchesterManchesterUK,Department of Evolutionary Biology, Ecology and Environmental SciencesUniversitat de BarcelonaBarcelonaSpain
| | - William J. Fletcher
- Quaternary Environments and Geoarchaeology Research Group, Department of Geography, School of Environment, Education and DevelopmentUniversity of ManchesterManchesterUK
| | - Peter A. Ryan
- Quaternary Environments and Geoarchaeology Research Group, Department of Geography, School of Environment, Education and DevelopmentUniversity of ManchesterManchesterUK
| |
Collapse
|
4
|
Dikshit A, Pradhan B, Huete A, Park HJ. Spatial based drought assessment: Where are we heading? A review on the current status and future. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 844:157239. [PMID: 35817119 DOI: 10.1016/j.scitotenv.2022.157239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/28/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Droughts are the most spatially complex natural hazards that exert global impacts and are further aggravated by climate change. The investigation of drought events is challenging as it involves numerous factors ranging from detection and assessment to modelling, management and mitigation. The analysis of these factors and their quantitative assessments have significantly evolved in recent times. In this paper, we review recent methods used to examine and model droughts from a spatial viewpoint. Our analysis was conducted at three spatial scales (point-wise, regional and global) and we evaluated how recent spatial methods have advanced our understanding of drought through case study examples. Further, we also examine and provide a broad overview of relevant case studies related to future drought occurrences under climate change. This study is a comprehensive synthesis of the various quantitative techniques used to assess the spatial characteristics of droughts at different spatial scales, and not an exhaustive review of all drought aspects. However, this serves as a basis for understanding the key milestones and advances accomplished through new spatial concepts relative to the traditional approaches to study drought. This work also aims to address the gaps in knowledge that are in need of further attention and provides recommendations to improve our understanding of droughts.
Collapse
Affiliation(s)
- Abhirup Dikshit
- Centre for Advanced Modelling and Geospatial Information Systems (CAMGIS), School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia
| | - Biswajeet Pradhan
- Centre for Advanced Modelling and Geospatial Information Systems (CAMGIS), School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia; Department of Energy and Mineral Resources Engineering, Sejong University, Choongmu-gwan, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Republic of Korea; Center of Excellence for Climate Change Research, King Abdulaziz University, P. O. Box 80234, Jeddah 21589, Saudi Arabia; Earth Observation Center, Institute of Climate Change, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
| | - Alfredo Huete
- Centre for Advanced Modelling and Geospatial Information Systems (CAMGIS), School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Hyuck-Jin Park
- Department of Energy and Mineral Resources Engineering, Sejong University, Choongmu-gwan, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Republic of Korea
| |
Collapse
|
5
|
Peringer A, Frank V, Snell RS. Climate change simulations in Alpine summer pastures suggest a disruption of current vegetation zonation. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
6
|
Hu HM, Shen CC, Chiang JCH, Trouet V, Michel V, Tsai HC, Valensi P, Spötl C, Starnini E, Zunino M, Chien WY, Sung WH, Chien YT, Chang P, Korty R. Split westerlies over Europe in the early Little Ice Age. Nat Commun 2022; 13:4898. [PMID: 35987980 PMCID: PMC9392774 DOI: 10.1038/s41467-022-32654-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 08/09/2022] [Indexed: 11/09/2022] Open
Abstract
The Little Ice Age (LIA; ca. 1450-1850 C.E.) is the best documented cold period of the past millennium, characterized by high-frequency volcanism, low solar activity, and high variability of Arctic sea-ice cover. Past studies of LIA Atlantic circulation changes have referenced the North Atlantic Oscillation (NAO), but recent studies have noted that LIA climate patterns appear to possess complexity not captured by an NAO analogue. Here, we present a new precipitation-sensitive stalagmite record from northern Italy that covers the past 800 years. We show that in the early LIA (1470-1610 C.E.), increased atmospheric ridging over northern Europe split the climatological westerlies away from central and northern Europe, possibly caused by concurrent Artic sea-ice reduction. With ongoing ice melting in the northern high latitudes and decreasing solar irradiance in the coming years, the early LIA may potentially serve as an analogue for European hydroclimatic conditions in the coming decades.
Collapse
Affiliation(s)
- Hsun-Ming Hu
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei, 10617, Taiwan, ROC
- Research Center for Future Earth, National Taiwan University, Taipei, 10617, Taiwan, ROC
| | - Chuan-Chou Shen
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei, 10617, Taiwan, ROC.
- Research Center for Future Earth, National Taiwan University, Taipei, 10617, Taiwan, ROC.
| | - John C H Chiang
- Department of Geography, University of California, Berkeley, CA, 94720, USA
- Research Institute for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Valerie Trouet
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, 85721, USA
| | - Véronique Michel
- Université Côte d'Azur, CNRS, CEPAM, Nice, 06300, France
- Université Côte d'Azur, CNRS, OCA, IRD, Géoazur, 06560, Valbonne, France
| | - Hsien-Chen Tsai
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei, 10617, Taiwan, ROC
- Research Center for Future Earth, National Taiwan University, Taipei, 10617, Taiwan, ROC
| | - Patricia Valensi
- HNHP, UMR 7194: CNRS-MNHN-UPVD, Paris, 75013, France
- Fondation IPH, Laboratoire de Préhistoire Nice-Côte d'Azur, Nice, 06300, France
| | - Christoph Spötl
- Institute of Geology, University of Innsbruck, Innsbruck, 6020, Austria
| | - Elisabetta Starnini
- Department of Civilizations and Forms of Knowledge, University of Pisa, Pisa, 56126, Italy
- Archaeological Superintendency of Liguria, Genova, 16126, Italy
| | - Marta Zunino
- Toirano Cave, Piazzale D. Maineri 1, Toirano (SV), 17055, Italy
| | - Wei-Yi Chien
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei, 10617, Taiwan, ROC
- Research Center for Future Earth, National Taiwan University, Taipei, 10617, Taiwan, ROC
| | - Wen-Hui Sung
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei, 10617, Taiwan, ROC
- Research Center for Future Earth, National Taiwan University, Taipei, 10617, Taiwan, ROC
| | - Yu-Tang Chien
- National Science and Technology Center for Disaster Reduction, New Taipei City, 23143, Taiwan, ROC
| | - Ping Chang
- Texas A&M University, College Station, TX, 77843, USA
| | - Robert Korty
- Texas A&M University, College Station, TX, 77843, USA
| |
Collapse
|
7
|
Nygaard PH, Bøhler F, Øyen B, Tveite B. Long-term spatiotemporal dynamics in a mountain birch ( Betula pubescens ssp. czerepanovii) forest in south-east Norway. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2022; 3:155-169. [PMID: 37283608 PMCID: PMC10168091 DOI: 10.1002/pei3.10087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/06/2022] [Accepted: 07/16/2022] [Indexed: 06/08/2023]
Abstract
Mountain birch forest covers large areas in Eurasia, and their ecological resilience provides important ecosystem services to human societies. This study describes long-term stand dynamics based on permanent plots in the upper mountain birch belt in SE Norway. We also present forest line changes over a period of 70 years. Inventories were conducted in 1931, 1953, and 2007. Overall, there were small changes from 1931 up to 1953 followed by a marked increase in biomass and dominant height of mountain birch throughout the period from 1953 to 2007. In addition, the biomass of spruce (Picea abies) and the number of plots with spruce present doubled. The high mortality rate of larger birch stems and large recruitment by sprouting since the 1960s reveal recurrent rejuvenation events after the earlier outbreak of the autumnal moth (Epirrita autumnata). Our results demonstrate both a high stem turnover in mountain birch and a great ability to recover after disturbances. This trend is interpreted as regrowth after a moth attack, but also long-term and time-lagged responses due to slightly improved growth conditions. An advance of the mountain birch forest line by 0.71 m year-1 from 1937 to 2007 was documented, resulting in a total reduction of the alpine area by 12%. Most of the changes in the forest line seem to have taken place after 1960. Regarding silviculture methods in mountain birch, a dimension cutting of larger birch trees with a cutting interval of c. 60 years seems to be a sustainable alternative for mimicking natural processes.
Collapse
Affiliation(s)
| | | | | | - Bjørn Tveite
- Norwegian Institute of Bioeconomy Research, NIBIOÅsNorway
| |
Collapse
|
8
|
Yang Y, Piper DJW, Xu M, Gao J, Jia J, Normandeau A, Chu D, Zhou L, Wang YP, Gao S. Northwestern Pacific tropical cyclone activity enhanced by increased Asian dust emissions during the Little Ice Age. Nat Commun 2022; 13:1712. [PMID: 35361795 PMCID: PMC8971422 DOI: 10.1038/s41467-022-29386-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
Instrumental records reveal that intense tropical cyclone (TC) activity varies with tropical sea surface temperature (SST) on annual-decadal scales. Drivers of intense TC activity at the centennial-millennial scale are less clear, due to the sparseness of pre-observational reconstructions. Here, we present a new 2 kyr continuous activity record of intense TCs from offshore eastern China. Our reconstruction indicates that this site witnessed enhanced TC activity during relatively warm periods, with a widespread increase in TC activity during the later part of the Little Ice Age. This latter observation reveals that enhanced TC activity was synchronized with increased Asian dust emissions during the Little Ice Age. TC activity was also lower in the late Roman Warm Period, when SST was higher but Asian dust emissions were lower than in the early phase. Such patterns suggest a centennial-millennial link between TC climatology and a combination of SST changes and Asian dust levels. Here, the authors show that enhanced tropical cyclone activity was synchronized with increased Asian dust emissions during the Little Ice Age, implying a mechanism linking tropical cyclone climatology to Asian dust levels, at 100 to 1000 year scales.
Collapse
Affiliation(s)
- Yang Yang
- School of Marine Science and Engineering, Nanjing Normal University, Nanjing, 210046, China. .,Natural Resources Canada, Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada.
| | - David J W Piper
- Natural Resources Canada, Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada
| | - Min Xu
- School of Marine Science and Engineering, Nanjing Normal University, Nanjing, 210046, China
| | - Jianhua Gao
- School of Geography and Ocean Science, Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing, 210093, China
| | - Jianjun Jia
- State Key Laboratory for Estuarine and Coastal Research, School of Marine Sciences, East China Normal University, Shanghai, 200062, China
| | - Alexandre Normandeau
- Natural Resources Canada, Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada
| | - Dongdong Chu
- Institute of Physical Oceanography and Remote Sensing, Ocean College, Zhejiang University, Zhoushan, 316000, China
| | - Liang Zhou
- School of Geography, Geomatics and Planning, Jiangsu Normal University, Xuzhou, 221116, China
| | - Ya Ping Wang
- School of Geography and Ocean Science, Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing, 210093, China.,State Key Laboratory for Estuarine and Coastal Research, School of Marine Sciences, East China Normal University, Shanghai, 200062, China
| | - Shu Gao
- School of Geography and Ocean Science, Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing, 210093, China.
| |
Collapse
|
9
|
Edvardsson J, Helama S, Rundgren M, Nielsen AB. The Integrated Use of Dendrochronological Data and Paleoecological Records From Northwest European Peatlands and Lakes for Understanding Long-Term Ecological and Climatic Changes—A Review. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.781882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our overall understanding of long-term climate dynamics is largely based on proxy data generated from archives such as ice cores, ocean sediments, tree rings, speleothems, and corals, whereas reconstructions of long-term changes in vegetation and associated climate during the Holocene are largely based on paleoecological records from peat and lake sequences, primarily pollen and plant macrofossil data. However, since no proxy can provide a complete picture of the past, it is important to integrate different types of data, and to use methods that can support the paleoecological and paleoclimatic interpretations. Here we review how tree-ring data and dendrochronological approaches can be integrated with stratigraphic records to provide complementary paleoecological and paleoclimatic information. The review includes multiproxy studies in which dendrochronological data have been either compared or integrated with stratigraphic records, mainly pollen records, with the aim to contribute to a better understanding of long-term ecosystem and climate dynamics. We mainly focus on studies from northwest Europe in which tree-ring data and at least one type of paleoecological proxy record from the same site or area has been either compared or integrated. We find that integration of dendrochronological data and paleoecological records from peat and lake sequences is a powerful but underutilized approach to reconstruct long-term ecological and climatic changes. One likely reason for its limited use is the contrasting character of the two categories of data, including their different time resolution and occurrence, making them difficult to integrate. For example, subfossil wood providing annual dendrochronological data usually only occurs sporadically in peat and lake sediments, and the presence/absence of the trees are normally expected to be recorded in the pollen data with multi-decadal or coarser resolution. Therefore, we also discuss methods to compare and integrate dendrochronological and stratigraphic records, as well as the relevant paleoecological and paleoclimatic information provided by dendrochronology, pollen, and peat stratigraphy, with the aim to facilitate new multi-proxy initiatives that will contribute to a better understanding of long-term ecosystem and climate dynamics and thereby a firmer basis for future nature conservation initiatives.
Collapse
|
10
|
Ichie T, Igarashi S, Yoshihara R, Takayama K, Kenzo T, Niiyama K, Nur Hajar ZS, Hyodo F, Tayasu I. Verification of the accuracy of the recent 50 years of tree growth and long‐term change in intrinsic water‐use efficiency using xylem Δ
14
C and δ
13
C in trees in an aseasonal tropical rainforest. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13823] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tomoaki Ichie
- Faculty of Agriculture and Marine Science Kochi University Nankoku Japan
| | - Shuichi Igarashi
- Faculty of Agriculture and Marine Science Kochi University Nankoku Japan
| | - Ryo Yoshihara
- Graduate School of Integrated Arts and Sciences Kochi University Nankoku Japan
| | - Kanae Takayama
- Faculty of Agriculture and Marine Science Kochi University Nankoku Japan
| | - Tanaka Kenzo
- Japan International Research Center for Agricultural Sciences Tsukuba Japan
| | - Kaoru Niiyama
- Forestry and Forest Products Research Institute Tsukuba Japan
| | | | - Fujio Hyodo
- Research Core for Interdisciplinary Sciences Okayama University Okayama Japan
| | - Ichiro Tayasu
- Research Institute for Humanity and Nature Kyoto Japan
| |
Collapse
|
11
|
Jiang Y, Cao Y, Zhang J, Li Z, Shi G, Han S, Coombs CEO, Liu C, Wang X, Wang J, Hao L, Xu Q, He H. A 168-year temperature recording based on tree rings and latitude differences in temperature changes in northeast China. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2021; 65:1859-1870. [PMID: 34013409 DOI: 10.1007/s00484-021-02142-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 04/25/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
A ring-width series was developed from Dahurian larch (Larix gmelinii) in the northeastern forest area of Inner Mongolia, China. By analyzing the relationships between tree-ring data and climate records, an August-September mean maximum temperature (T89) series during 1845 and 2012 was reconstructed based on a simple linear regression equation. This reconstructed series explained 40.9% variance of the observed temperature from 1959 to 2012. The reconstructed T89 series was consistent with the historical disaster events caused by extreme climate (e.g., flood, frost disaster, and cold damage). Besides, the temperature comparisons showed that the year in which the warm months (April-September) in northeast China began to warm up has latitude differences. It started with a gradual delay from north to south, starting 1980 in the south region, after 1950 AD in the central region and after 1940 in the north region. Our study can enrich high-resolution temperature series in Northeast China and help clarify the characteristic of recent warming in northeast China.
Collapse
Affiliation(s)
- Yangao Jiang
- Experimental Teaching Center, Shenyang Normal University, Shenyang, 110034, China
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Yuting Cao
- College of Life Sciences, Shenyang Normal University, Shenyang, 110034, China
| | - Junhui Zhang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
| | - Zhuo Li
- Changbai Mountain Academy of Sciences, Erdaobaihe, Jilin Province, 133613, China
| | - Guoqiang Shi
- Changbai Mountain Academy of Sciences, Erdaobaihe, Jilin Province, 133613, China
| | - Shijie Han
- School of Life Sciences, Henan University, Kaifeng, 475004, China.
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
| | - Cassius E O Coombs
- Centre for Carbon, Water and Food, School of Life and Environmental Sciences, University of Sydney, Camden, NSW, 2570, Australia
| | - Chuan Liu
- College of Life Sciences, Shenyang Normal University, Shenyang, 110034, China
| | - Xiaoguang Wang
- College of Environmental and Resource Sciences, Dalian Minzu University, Dalian, 116600, China
| | - Junwei Wang
- Experimental Teaching Center, Shenyang Normal University, Shenyang, 110034, China
| | - Lin Hao
- College of Life Sciences, Shenyang Normal University, Shenyang, 110034, China
| | - Qi Xu
- Experimental Teaching Center, Shenyang Normal University, Shenyang, 110034, China
| | - Haisheng He
- Experimental Teaching Center, Shenyang Normal University, Shenyang, 110034, China
| |
Collapse
|
12
|
Testing the CMIP6 GCM Simulations versus Surface Temperature Records from 1980–1990 to 2011–2021: High ECS Is Not Supported. CLIMATE 2021. [DOI: 10.3390/cli9110161] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The last-generation CMIP6 global circulation models (GCMs) are currently used to interpret past and future climatic changes and to guide policymakers, but they are very different from each other; for example, their equilibrium climate sensitivity (ECS) varies from 1.83 to 5.67 °C (IPCC AR6, 2021). Even assuming that some of them are sufficiently reliable for scenario forecasts, such a large ECS uncertainty requires a pre-selection of the most reliable models. Herein the performance of 38 CMIP6 models are tested in reproducing the surface temperature changes observed from 1980–1990 to 2011–2021 in three temperature records: ERA5-T2m, ERA5-850mb, and UAH MSU v6.0 Tlt. Alternative temperature records are briefly discussed but found to be not appropriate for the present analysis because they miss data over large regions. Significant issues emerge: (1) most GCMs overestimate the warming observed during the last 40 years; (2) there is great variability among the models in reconstructing the climatic changes observed in the Arctic; (3) the ocean temperature is usually overestimated more than the land one; (4) in the latitude bands 40° N–70° N and 50° S–70° S (which lay at the intersection between the Ferrel and the polar atmospheric cells) the CMIP6 GCMs overestimate the warming; (5) similar discrepancies are present in the east-equatorial pacific region (which regulates the ENSO) and in other regions where cooling trends are observed. Finally, the percentage of the world surface where the (positive or negative) model-data discrepancy exceeds 0.2, 0.5 and 1.0 °C is evaluated. The results indicate that the models with low ECS values (for example, 3 °C or less) perform significantly better than those with larger ECS. Therefore, the low ECS models should be preferred for climate change scenario forecasts while the other models should be dismissed and not used by policymakers. In any case, significant model-data discrepancies are still observed over extended world regions for all models: on average, the GCM predictions disagree from the data by more than 0.2 °C (on a total mean warming of about 0.5 °C from 1980–1990 to 2011–2021) over more than 50% of the global surface. This result suggests that climate change and its natural variability remain poorly modeled by the CMIP6 GCMs. Finally, the ECS uncertainty problem is discussed, and it is argued (also using semi-empirical climate models that implement natural oscillations not predicted by the GCMs) that the real ECS could be between 1 and 2 °C, which implies moderate warming for the next decades.
Collapse
|
13
|
Zhang X, Wang YP, Rayner PJ, Ciais P, Huang K, Luo Y, Piao S, Wang Z, Xia J, Zhao W, Zheng X, Tian J, Zhang Y. A small climate-amplifying effect of climate-carbon cycle feedback. Nat Commun 2021; 12:2952. [PMID: 34011925 PMCID: PMC8134589 DOI: 10.1038/s41467-021-22392-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 03/10/2021] [Indexed: 11/09/2022] Open
Abstract
The climate-carbon cycle feedback is one of the most important climate-amplifying feedbacks of the Earth system, and is quantified as a function of carbon-concentration feedback parameter (β) and carbon-climate feedback parameter (γ). However, the global climate-amplifying effect from this feedback loop (determined by the gain factor, g) has not been quantified from observations. Here we apply a Fourier analysis-based carbon cycle feedback framework to the reconstructed records from 1850 to 2017 and 1000 to 1850 to estimate β and γ. We show that the β-feedback varies by less than 10% with an average of 3.22 ± 0.32 GtC ppm-1 for 1880-2017, whereas the γ-feedback increases from -33 ± 14 GtC K-1 on a decadal scale to -122 ± 60 GtC K-1 on a centennial scale for 1000-1850. Feedback analysis further reveals that the current amplification effect from the carbon cycle feedback is small (g is 0.01 ± 0.05), which is much lower than the estimates by the advanced Earth system models (g is 0.09 ± 0.04 for the historical period and is 0.15 ± 0.08 for the RCP8.5 scenario), implying that the future allowable CO2 emissions could be 9 ± 7% more. Therefore, our findings provide new insights about the strength of climate-carbon cycle feedback and about observational constraints on models for projecting future climate.
Collapse
Affiliation(s)
- Xuanze Zhang
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China. .,Research Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Science, East China Normal University, Shanghai, China.
| | - Ying-Ping Wang
- Terrestrial Biogeochemistry Group, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China. .,CSIRO Oceans and Atmosphere, Private Bag 1, Aspendale, Victoria, Australia.
| | - Peter J Rayner
- School of Earth Sciences, Climate and Energy College, University of Melbourne, Parkville, Victoria, Australia
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Kun Huang
- Research Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Science, East China Normal University, Shanghai, China
| | - Yiqi Luo
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Shilong Piao
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Zhonglei Wang
- Wang Yanan Institute for Studies in Economics (WISE) and School of Economics, Xiamen University, Xiamen, China
| | - Jianyang Xia
- Research Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Science, East China Normal University, Shanghai, China
| | - Wei Zhao
- National Meteorological Center, China Meteorological Administration, Beijing, China
| | - Xiaogu Zheng
- Key Laboratory of Regional Climate-Environment Research for East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
| | - Jing Tian
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Yongqiang Zhang
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
14
|
Climate Variability in Central Europe during the Last 2500 Years Reconstructed from Four High-Resolution Multi-Proxy Speleothem Records. GEOSCIENCES 2021. [DOI: 10.3390/geosciences11040166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Late Holocene was characterized by several centennial-scale climate oscillations including the Roman Warm Period, the Dark Ages Cold Period, the Medieval Warm Period and the Little Ice Age. The detection and investigation of such climate anomalies requires paleoclimate archives with an accurate chronology as well as a high temporal resolution. Here, we present 230Th/U-dated high-resolution multi-proxy records (δ13C, δ18O and trace elements) for the last 2500 years of four speleothems from Bunker Cave and the Herbstlabyrinth cave system in Germany. The multi-proxy data of all four speleothems show evidence of two warm and two cold phases during the last 2500 years, which coincide with the Roman Warm Period and the Medieval Warm Period, as well as the Dark Ages Cold Period and the Little Ice Age, respectively. During these four cold and warm periods, the δ18O and δ13C records of all four speleothems and the Mg concentration of the speleothems Bu4 (Bunker Cave) and TV1 (Herbstlabyrinth cave system) show common features and are thus interpreted to be related to past climate variability. Comparison with other paleoclimate records suggests a strong influence of the North Atlantic Oscillation at the two caves sites, which is reflected by warm and humid conditions during the Roman Warm Period and the Medieval Warm Period, and cold and dry climate during the Dark Ages Cold period and the Little Ice Age. The Mg records of speleothems Bu1 (Bunker Cave) and NG01 (Herbstlabyrinth) as well as the inconsistent patterns of Sr, Ba and P suggests that the processes controlling the abundance of these trace elements are dominated by site-specific effects rather than being related to supra-regional climate variability.
Collapse
|
15
|
Climate Change along the Silk Road and Its Influence on Scythian Cultural Expansion and Rise of the Mongol Empire. SUSTAINABILITY 2021. [DOI: 10.3390/su13052530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Climate change and cultural exchange both influenced cultural development along the continental Silk Road during the late Holocene, but climate change and its influence on nomadic civilizations during that time has yet to be systematically assessed. In this study, we analyzed records of climate change along the Silk Road covering key periods in the late Holocene, based on multiproxies from various archives including lake sediments, shorelines/beach ridges, peatlands, ice cores, tree rings, aeolian sediments, moraines, and historical documents. Combined with archaeological data, we assessed the influence of climate on development and expansion of representative pastoral nomadism. Our results show that the most notable climate changes in Central Asia were characterized by decreasing temperature, expanding glaciers, increasing precipitation, and increasing humidity during transitions from the Sub-Boreal to Sub-Atlantic Period (ca. 9–8th century BC) and from the Medieval Warm Period to the Little Ice Age (ca. 13–14th century AD). The two periods coincided with Scythian Cultural expansion across the steppe landscape of Central Asia and rise of the Mongol Empire, respectively. These temporal coincidences are interpreted as causally related, where temperature fall and glacial advance may have forced the pastoral nomadism to southward migration. Coeval wetness and southward migration of steppe landscape in Central Asia were beneficial for these cultural expansions, which spanned the Eurasian arid and semi-arid zone westward. Therefore, during the historical period when productivity was underdeveloped, although expansions of pastoral nomadism were closely related to internal social structures, climate change was possibly the most critical controlling factor for sustainability development and collapse.
Collapse
|
16
|
Reconstruction of the Interannual to Millennial Scale Patterns of the Global Surface Temperature. ATMOSPHERE 2021. [DOI: 10.3390/atmos12020147] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Climate changes are due to anthropogenic factors, volcano eruptions and the natural variability of the Earth’s system. Herein the natural variability of the global surface temperature is modeled using a set of harmonics spanning from the inter-annual to the millennial scales. The model is supported by the following considerations: (1) power spectrum evaluations show 11 spectral peaks (from the sub-decadal to the multi-decadal scales) above the 99% confidence level of the known temperature uncertainty; (2) spectral coherence analysis between the independent global surface temperature periods 1861–1937 and 1937–2013 highlights at least eight common frequencies between 2- and 20-year periods; (3) paleoclimatic temperature reconstructions during the Holocene present secular to millennial oscillations. The millennial oscillation was responsible for the cooling observed from the Medieval Warm Period (900–1400) to the Little Ice Age (1400–1800) and, on average, could have caused about 50% of the warming observed since 1850. The finding implies an equilibrium climate sensitivity of 1.0–2.3 °C for CO2 doubling likely centered around 1.5 °C. This low sensitivity to radiative forcing agrees with the conclusions of recent studies. Semi-empirical models since 1000 A.D. are developed using 13 identified harmonics (representing the natural variability of the climate system) and a climatic function derived from the Coupled Model Intercomparison Project 5 (CMIP5) model ensemble mean simulation (representing the mean greenhouse gas—GHG, aerosol, and volcano temperature contributions) scaled under the assumption of an equilibrium climate sensitivity of 1.5 °C. The harmonic model is evaluated using temperature data from 1850 to 2013 to test its ability to predict the major temperature patterns observed in the record from 2014 to 2020. In the short, medium, and long time scales the semi-empirical models predict: (1) temperature maxima in 2015–2016 and 2020, which is confirmed by the 2014–2020 global temperature record; (2) a relatively steady global temperature from 2000 to 2030–2040; (3) a 2000–2100 mean projected global warming of about 1 °C. The semi-empirical model reconstructs accurately the historical surface temperature record since 1850 and hindcasts mean surface temperature proxy reconstructions since the medieval period better than the model simulation that is unable to simulate the Medieval Warm Period.
Collapse
|
17
|
Li Q, Liu Y, Nakatsuka T, Liu R, Cai Q, Song H, Wang S, Sun C, Fang C. Delayed warming in Northeast China: Insights from an annual temperature reconstruction based on tree-ring δ 18O. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:141432. [PMID: 32805438 DOI: 10.1016/j.scitotenv.2020.141432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/09/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Global warming has had an unprecedented impact on environmental changes and thus human life in mid-high latitude regions. As one of the areas most affected by global warming, Northeast China has suffered from a series of ecological crises, including warming-induced water deficits, permafrost thaw, and extended growing seasons. The change in annual average temperature (annual T) variations in Northeast China since the Industrial Revolution are still not fully understood, mainly because of the lack of long-term instrumental data and high-resolution annual T reconstructions. Here, we present the first annual T reconstruction (r = -0.683, p < .001, n = 60) for 1818-2012 in Northeast China, which may also be the first temperature reconstruction based on tree-ring δ18O in China. The reconstruction is significantly related to temperature variations over mid-high latitude Eurasia and agree (p < .01) with several long-term hydroclimatic reconstructions in the surrounding area. When the internal variability in the reconstruction was high, the decadal to multidecadal cycles were significant. Further analysis found that the reconstruction was mainly affected by the East Asian Summer Monsoon (EASM) and North Atlantic Oscillation (NAO). The reconstruction was significantly negatively correlated with several time series of annual T in the Northern Hemisphere, which showed that there is a substantial difference in annual T between Northeast China and other regions of the Northern Hemisphere. The difference mainly existed before the 1950s. From the 1850s to the 1950s, the annual T in Northeast China decreased slightly. However, extreme warming began in the 1950s in Northeast China, and this warming has been unprecedented during the past two centuries. If the warming trend since the 1950s continues, then it will lead to devastating disasters to forest and permafrost ecosystems in Northeast China.
Collapse
Affiliation(s)
- Qiang Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China.
| | - Yu Liu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China; School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Takeshi Nakatsuka
- Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan
| | - Ruoshi Liu
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qiufang Cai
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China
| | - Huiming Song
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China
| | - Shengjie Wang
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
| | - Changfeng Sun
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China
| | - Congxi Fang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China
| |
Collapse
|
18
|
van Helmond NAGM, Lougheed BC, Vollebregt A, Peterse F, Fontorbe G, Conley DJ, Slomp CP. Recovery from multi-millennial natural coastal hypoxia in the Stockholm Archipelago, Baltic Sea, terminated by modern human activity. LIMNOLOGY AND OCEANOGRAPHY 2020; 65:3085-3097. [PMID: 33362297 PMCID: PMC7754161 DOI: 10.1002/lno.11575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/06/2020] [Accepted: 07/16/2020] [Indexed: 05/05/2023]
Abstract
Enhanced nutrient input and warming have led to the development of low oxygen (hypoxia) in coastal waters globally. For many coastal areas, insight into redox conditions prior to human impact is lacking. Here, we reconstructed bottom water redox conditions and sea surface temperatures (SSTs) for the coastal Stockholm Archipelago over the past 3000 yr. Elevated sedimentary concentrations of molybdenum indicate (seasonal) hypoxia between 1000 b.c.e. and 1500 c.e. Biomarker-based (TEX86) SST reconstructions indicate that the recovery from hypoxia after 1500 c.e. coincided with a period of significant cooling (∼ 2°C), while human activity in the study area, deduced from trends in sedimentary lead and existing paleobotanical and archeological records, had significantly increased. A strong increase in sedimentary lead and zinc, related to more intense human activity in the 18th and 19th century, and the onset of modern warming precede the return of hypoxia in the Stockholm Archipelago. We conclude that climatic cooling played an important role in the recovery from natural hypoxia after 1500 c.e., but that eutrophication and warming, related to modern human activity, led to the return of hypoxia in the 20th century. Our findings imply that ongoing global warming may exacerbate hypoxia in the coastal zone of the Baltic Sea.
Collapse
Affiliation(s)
- Niels A. G. M. van Helmond
- Department of Earth Sciences, Faculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
- Department of GeologyLund UniversityLundSweden
| | - Bryan C. Lougheed
- Department of Earth SciencesUppsala UniversityUppsalaSweden
- Laboratoire des Sciences du Climat et de l'EnvironnementLSCE/IPSL, CEA CNRS‐UVSQ, Université Paris‐SaclayGif‐sur‐YvetteFrance
| | - Annika Vollebregt
- Department of Earth Sciences, Faculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
| | - Francien Peterse
- Department of Earth Sciences, Faculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
| | | | | | - Caroline P. Slomp
- Department of Earth Sciences, Faculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
| |
Collapse
|
19
|
Erb MP, Emile-Geay J, Hakim GJ, Steiger N, Steig EJ. Atmospheric dynamics drive most interannual U.S. droughts over the last millennium. SCIENCE ADVANCES 2020; 6:eaay7268. [PMID: 32821813 PMCID: PMC7413725 DOI: 10.1126/sciadv.aay7268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
The American West exemplifies drought-sensitive regions with growing populations. Paleoclimate investigations have documented severe droughts in this region before European settling, with major implications for water management and planning. Here, we leverage paleoclimate data assimilation to reconstruct past climate states, enabling a large-scale multivariate investigation of U.S. drought dynamics over the last millennium. These results confirm that La Niña conditions significantly influence southwest U.S. drought over the past millennium but only account for, by one metric, ~13% of interannual drought variability in that region. Atlantic sea surface temperatures may also contribute a small influence, but unexplained variability suggests a substantial role for internal atmospheric variability. This conclusion is buttressed by analysis of simulations from the Community Earth System Model Last Millennium Ensemble. While greenhouse gases will increase future drought risk, as shown in other work, interannual U.S. drought variations will also be widely influenced by processes internal to the atmosphere.
Collapse
Affiliation(s)
- M. P. Erb
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - J. Emile-Geay
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
| | - G. J. Hakim
- Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
| | - N. Steiger
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - E. J. Steig
- Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
- Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA
| |
Collapse
|
20
|
Caribbean cyclone activity: an annually-resolved Common Era record. Sci Rep 2020; 10:11780. [PMID: 32678192 PMCID: PMC7367345 DOI: 10.1038/s41598-020-68633-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 06/30/2020] [Indexed: 11/15/2022] Open
Abstract
Tropical cyclones (TC) represent a substantial threat to life and property for Caribbean and adjacent populations. The prospective increase of TC magnitudes, expressed in the 15th chapter of the IPCC AR5 report, entails a rising probability of ecological and social disasters, which were tragically exemplified by several severe Caribbean TC strikes during the past 20 years. Modern IPCC-grade climate models, however, still lack the required spatial and temporal resolution to accurately consider the underlying boundary conditions that modulate long-time TC patterns beyond the Instrumental Era. It is thus necessary to provide a synoptic mechanistic understanding regarding the origin of such long-time patterns, in order to predict reliable changes of TC magnitude and frequency under future climate scenarios. Caribbean TC records are still rare and often lack the necessary continuity and resolution to overcome these limitations. Here, we report on an annually-resolved sedimentary archive from the bottom of the Great Blue Hole (Lighthouse Reef, Belize). The TC record encompasses 1885 years and extends all existing site-specific TC archives both in terms of resolution and duration. We identified a likely connection between long-term TC patterns and climate phenomena responses to Common Era climate variations and offer a conceptual and comparative view considering several involved tropospheric and oceanographic control mechanisms such as the El-Niño-Southern-Oscillation, the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. These basin-scaled climate modes exercise internal control on TC activity by modulating the thermodynamic environment (sea-surface temperature and vertical wind shear stress dynamics) for enhanced/suppressed TC formation both on millennial (primary) and multi-decadal (secondary) time scales. We interpret the beginning of the Medieval Warm Period (MWP) as an important time interval of the Common Era record and suspect that the southward migration of the intertropical convergence zone (ITCZ) caused, in combination with extensive hydro-climate changes, a shift in the tropical Atlantic TC regime. The TC activity in the south-western Caribbean changed in general from a stable and less active stage (100–900 CE) to a more active and variable state (1,100 CE-modern).
Collapse
|
21
|
How Much Human-Caused Global Warming Should We Expect with Business-As-Usual (BAU) Climate Policies? A Semi-Empirical Assessment. ENERGIES 2020. [DOI: 10.3390/en13061365] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In order to assess the merits of national climate change mitigation policies, it is important to have a reasonable benchmark for how much human-caused global warming would occur over the coming century with “Business-As-Usual” (BAU) conditions. However, currently, policymakers are limited to making assessments by comparing the Global Climate Model (GCM) projections of future climate change under various different “scenarios”, none of which are explicitly defined as BAU. Moreover, all of these estimates are ab initio computer model projections, and policymakers do not currently have equivalent empirically derived estimates for comparison. Therefore, estimates of the total future human-caused global warming from the three main greenhouse gases of concern (CO2, CH4, and N2O) up to 2100 are here derived for BAU conditions. A semi-empirical approach is used that allows direct comparisons between GCM-based estimates and empirically derived estimates. If the climate sensitivity to greenhouse gases implies a Transient Climate Response (TCR) of ≥ 2.5 °C or an Equilibrium Climate Sensitivity (ECS) of ≥ 5.0 °C then the 2015 Paris Agreement’s target of keeping human-caused global warming below 2.0 °C will have been broken by the middle of the century under BAU. However, for a TCR < 1.5 °C or ECS < 2.0 °C, the target would not be broken under BAU until the 22nd century or later. Therefore, the current Intergovernmental Panel on Climate Change (IPCC) “likely” range estimates for TCR of 1.0 to 2.5 °C and ECS of 1.5 to 4.5 °C have not yet established if human-caused global warming is a 21st century problem.
Collapse
|
22
|
Toulkeridis T, Tamayo E, Simón-Baile D, Merizalde-Mora MJ, Reyes –Yunga DF, Viera-Torres M, Heredia M. Climate Change according to Ecuadorian academics–Perceptions versus facts. ACTA ACUST UNITED AC 2020. [DOI: 10.17163/lgr.n31.2020.02] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Climate change has become one of the most important topics in each country’s government agendas. The current effects demand quicker actions in order to decrease the speed at which the global warming and climate is changing, which are commonly seen in global agreements to reduce pollution. However, the main changes to face and mitigate such phenomena depends on each country´s decision and not on global agreements as the causes are continent-wide although the effects and magnitudes may be local. One of the key components for an effective adaption and mitigation is the role that the population have over national decisions. For this reason, the level of awareness and knowledge about what is occurring in their surroundings vital, thus the importance of a correct information broadcast and education. For the aforementioned reasons, the current study compares the recent perception of a well-educated Ecuadorean community regarding the climate change worldwide and in Ecuador with the scientific evidence and historical facts, and how it affects its vulnerability to the climate change effects.
Collapse
|
23
|
Lu Y, Li H, Si B, Li M. Chloride tracer of the loess unsaturated zone under sub-humid region: A potential proxy recording high-resolution hydroclimate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 700:134465. [PMID: 31706090 DOI: 10.1016/j.scitotenv.2019.134465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/08/2019] [Accepted: 09/13/2019] [Indexed: 06/10/2023]
Abstract
A high-resolution hydroclimate archive is critical to understanding the past changes, but such hydroclimatic reconstructions are extremely limited. Our study aims to examine the potential of the chloride tracer (Cl) within unsaturated zone (USZ) to reconstruct high-resolution hydroclimate records. We investigated a representative sub-humid monsoon area of the Chinese Loess highland, where piston flow recharge dominates and a constant rate of Cl input occurs. We successfully reconstructed a 1007-yr hydroclimate record with a 2-yr sampling resolution using a 95-m USZ Cl profile. Excluding the recycling and mixing zone, and the groundwater affecting zone, six relatively humid phases and five relatively dry phases were discernible. The uncertainty in the time of wet/dry phase decreases as the accumulated time increases, and the minimal recharge uncertainty is 16% over a 10-yr time scale. The reconstructed hydroclimate record from the semi-humid region has a much higher resolution than that of the arid zones, likely because the semi-humid, fine-grained thick USZ, possesses higher velocity piston flow, relatively to diffusion and dispersion of Cl signals. The record compared well with other related records, suggesting that the Cl proxy can be used in sub-humid areas, and is sensitive to wet/dry alternations that are largely driven by the Asian monsoon intensity. To the best of our knowledge, this is the first investigation of the USZ Cl to hydroclimatic reconstruction in a non-arid region. The high-resolution hydroclimate record may deepen our understanding of the hydrological process in the deep USZ, past climate and water resources, and promote developments of the hydropedology and global change science.
Collapse
Affiliation(s)
- Yanwei Lu
- Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, China
| | - Huijie Li
- Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, China
| | - Bingcheng Si
- Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, China; Department of Soil Science, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada.
| | - Min Li
- Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, China.
| |
Collapse
|
24
|
Kern OA, Koutsodendris A, Mächtle B, Christanis K, Schukraft G, Scholz C, Kotthoff U, Pross J. XRF core scanning yields reliable semiquantitative data on the elemental composition of highly organic-rich sediments: Evidence from the Füramoos peat bog (Southern Germany). THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134110. [PMID: 31487594 DOI: 10.1016/j.scitotenv.2019.134110] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/29/2019] [Accepted: 08/24/2019] [Indexed: 06/10/2023]
Abstract
X-ray fluorescence core scanning (XRF-CS) has become a standard tool in paleoenvironmental studies. Allowing rapid, inexpensive and non-destructive analysis of the elemental composition of sediment cores at high spatial resolution, it is ideally suited for the reconstruction of short-term climatic change. However, its applicability to cores consisting of peat and other highly organic-rich sediments has yet remained poorly explored. We have therefore investigated the application of XRF-CS to two cores consisting of ombrotrophic peat and of fen peat and organic-rich muds of Late Glacial-Holocene and Eemian age, respectively, from a peat bog in Southern Germany using an Avaatech 4th-generation XRF core scanner. The XRF-CS-derived distributions of elements widely used in (paleo)environmental research (i.e., Al, Ca, Fe, K, Mg, Mn, S, Si, and Ti) were systematically compared to the results of inductively coupled plasma optical emission spectrometry analyses. For the Late Glacial-Holocene peat core, XRF-CS yielded reliable semiquantitative data for the majority of the investigated elements (i.e., Ca, Fe, K, Mn, S, Si, and Ti), with R2 ≥ 0.5. XRF-CS of the Eemian fen peat and organic-rich muds yielded reliable data for Al, K, S, and Ti (R2 ≥ 0.5) and, to a lesser extent, for Fe (R2 = 0.46). and Si (R2 = 0.25). This indicates that XRF-CS allows to semiquantitatively reconstruct the distribution of the majority of paleoclimatically relevant elements in peat and other highly organic-rich sediments. Hence, XRF-CS is well suited to complement the analytical toolbox for the paleoenvironmental study of such sediments.
Collapse
Affiliation(s)
- Oliver A Kern
- Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany.
| | - Andreas Koutsodendris
- Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany.
| | - Bertil Mächtle
- Institute of Geography, Heidelberg University, Im Neuenheimer Feld 348, 69120 Heidelberg, Germany.
| | - Kimon Christanis
- Department of Geology, University of Patras, 26504 Rio-Patras, Greece.
| | - Gerd Schukraft
- Institute of Geography, Heidelberg University, Im Neuenheimer Feld 348, 69120 Heidelberg, Germany.
| | - Christian Scholz
- Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany.
| | - Ulrich Kotthoff
- Center of Natural History and Institute of Geology, University of Hamburg, Bundesstraße 55, 20146 Hamburg, Germany.
| | - Jörg Pross
- Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany.
| |
Collapse
|
25
|
Abstract
We present a high-resolution, replicated speleothem δ18O record from Klang Cave in southern Thailand that characterizes rainfall variation in NCIP over the past 2,700 y. This record reveals notable dry climate conditions during the current and past warm periods, similar to the observations in SCIP, which resemble enhanced El Niño-like conditions. Using a newly developed ITCZ shift index, we find a southward shifted ITCZ during the early MWP and the CWP. Our results suggest that detecting changes in rainfall due to anthropogenic forcing still remains indistinguishable from natural variability in the northern tropics. Tropical rainfall variability is closely linked to meridional shifts of the Intertropical Convergence Zone (ITCZ) and zonal movements of the Walker circulation. The characteristics and mechanisms of tropical rainfall variations on centennial to decadal scales are, however, still unclear. Here, we reconstruct a replicated stalagmite-based 2,700-y-long, continuous record of rainfall for the deeply convective northern central Indo-Pacific (NCIP) region. Our record reveals decreasing rainfall in the NCIP over the past 2,700 y, similar to other records from the northern tropics. Notable centennial- to decadal-scale dry climate episodes occurred in both the NCIP and the southern central Indo-Pacific (SCIP) during the 20th century [Current Warm Period (CWP)] and the Medieval Warm Period (MWP), resembling enhanced El Niño-like conditions. Further, we developed a 2,000-y-long ITCZ shift index record that supports an overall southward ITCZ shift in the central Indo-Pacific and indicates southward mean ITCZ positions during the early MWP and the CWP. As a result, the drying trend since the 20th century in the northern tropics is similar to that observed during the past warm period, suggesting that a possible anthropogenic forcing of rainfall remains indistinguishable from natural variability.
Collapse
|
26
|
The Asian Summer Monsoon: Teleconnections and Forcing Mechanisms—A Review from Chinese Speleothem δ18O Records. QUATERNARY 2019. [DOI: 10.3390/quat2030026] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Asian summer monsoon (ASM) variability significantly affects hydro-climate, and thus socio-economics, in the East Asian region, where nearly one-third of the global population resides. Over the last two decades, speleothem δ18O records from China have been utilized to reconstruct ASM variability and its underlying forcing mechanisms on orbital to seasonal timescales. Here, we use the Speleothem Isotopes Synthesis and Analysis database (SISAL_v1) to present an overview of hydro-climate variability related to the ASM during three periods: the late Pleistocene, the Holocene, and the last two millennia. We highlight the possible global teleconnections and forcing mechanisms of the ASM on different timescales. The longest composite stalagmite δ18O record over the past 640 kyr BP from the region demonstrates that ASM variability on orbital timescales is dominated by the 23 kyr precessional cycles, which are in phase with Northern Hemisphere summer insolation (NHSI). During the last glacial, millennial changes in the intensity of the ASM appear to be controlled by North Atlantic climate and oceanic feedbacks. During the Holocene, changes in ASM intensity were primarily controlled by NHSI. However, the spatio-temporal distribution of monsoon rain belts may vary with changes in ASM intensity on decadal to millennial timescales.
Collapse
|
27
|
Bantan RA, Abu-Zied RH, Al-Dubai TA. Late Holocene Environmental Changes in a Sediment Core from Al-Kharrar Lagoon, Eastern Red Sea Coast, Saudi Arabia. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2019. [DOI: 10.1007/s13369-019-03958-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
28
|
Neukom R, Barboza LA, Erb MP, Shi F, Emile-Geay J, Evans MN, Franke J, Kaufman DS, Lücke L, Rehfeld K, Schurer A, Zhu F, Brönnimann S, Hakim GJ, Henley BJ, Ljungqvist FC, McKay N, Valler V, von Gunten L. Consistent multi-decadal variability in global temperature reconstructions and simulations over the Common Era. NATURE GEOSCIENCE 2019; 12:643-649. [PMID: 31372180 PMCID: PMC6675609 DOI: 10.1038/s41561-019-0400-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 06/05/2019] [Indexed: 06/10/2023]
Abstract
Multi-decadal surface temperature changes may be forced by natural as well as anthropogenic factors, or arise unforced from the climate system. Distinguishing these factors is essential for estimating sensitivity to multiple climatic forcings and the amplitude of the unforced variability. Here we present 2,000-year-long global mean temperature reconstructions using seven different statistical methods that draw from a global collection of temperature-sensitive paleoclimate records. Our reconstructions display synchronous multi-decadal temperature fluctuations, which are coherent with one another and with fully forced CMIP5 millennial model simulations across the Common Era. The most significant attribution of pre-industrial (1300-1800 CE) variability at multi-decadal timescales is to volcanic aerosol forcing. Reconstructions and simulations qualitatively agree on the amplitude of the unforced global mean multi-decadal temperature variability, thereby increasing confidence in future projections of climate change on these timescales. The largest warming trends at timescales of 20 years and longer occur during the second half of the 20th century, highlighting the unusual character of the warming in recent decades.
Collapse
Affiliation(s)
- Raphael Neukom
- Oeschger Centre for Climate Change Research and Institute of Geography, University of Bern, Switzerland
| | - Luis A Barboza
- Escuela de Matematica-CIMPA, Universidad de Costa Rica, San Jose, Costa Rica
| | - Michael P Erb
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - Feng Shi
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - Julien Emile-Geay
- Department of Earth Sciences and Center for Applied Mathematical Sciences, University of Southern California, Los Angeles, CA, USA
| | - Michael N Evans
- Department of Geology and ESSIC, University of Maryland, College Park, MD USA
| | - Jörg Franke
- Oeschger Centre for Climate Change Research and Institute of Geography, University of Bern, Switzerland
| | - Darrell S Kaufman
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - Lucie Lücke
- School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Kira Rehfeld
- British Antarctic Survey, Cambridge, United Kingdom
- Institute of Environmental Physics, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Andrew Schurer
- School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Feng Zhu
- Department of Earth Sciences and Center for Applied Mathematical Sciences, University of Southern California, Los Angeles, CA, USA
| | - Stefan Brönnimann
- Oeschger Centre for Climate Change Research and Institute of Geography, University of Bern, Switzerland
| | - Gregory J Hakim
- Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
| | - Benjamin J Henley
- School of Earth Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Fredrik Charpentier Ljungqvist
- Department of History, Stockholm University, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
- Department of Geography, University of Cambridge, Cambridge, United Kingdom
| | - Nicholas McKay
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - Veronika Valler
- Oeschger Centre for Climate Change Research and Institute of Geography, University of Bern, Switzerland
| | | |
Collapse
|
29
|
A Physical–Mathematical Approach to Climate Change Effects through Stochastic Resonance. CLIMATE 2019. [DOI: 10.3390/cli7020021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The aim of this work is to study the effects induced by climate changes in the framework of the stochastic resonance approach. First, a wavelet cross-correlation analysis on Earth temperature data concerning the last 5,500,000 years is performed; this analysis confirms a correlation between the planet’s temperature and the 100,000, 41,000, and 23,000-year periods of the Milankovitch orbital cycles. Then, the stochastic resonance model is invoked. Specific attention is given to the study of the impact of the registered global temperature increase within the stochastic model. Further, a numerical simulation has been performed, based on: (1) A double-well potential, (2) an external periodic modulation, corresponding to the orbit eccentricity cycle, and (3) an increased value of the global Earth temperature. The effect of temperature increase represents one of the novelties introduced in the present study and is determined by downshifting the interaction potential used within the stochastic resonance model. The numeric simulation results show that, for simulated increasing values of the global temperature, the double-well system triggers changes, while at higher temperatures (as in the case of the absence of a global temperature increase although with a different threshold) the system goes into a chaotic regime. The wavelet analysis allows characterization of the stochastic resonance condition through the evaluation of the signal-to-noise ratio. On the basis of the obtained findings, we hypothesize that the global temperature increase can suppress, on a large time scale corresponding to glacial cycles, the external periodic modulation effects and, hence, the glacial cycles.
Collapse
|
30
|
Ilyashuk EA, Heiri O, Ilyashuk BP, Koinig KA, Psenner R. The Little Ice Age signature in a 700-year high-resolution chironomid record of summer temperatures in the Central Eastern Alps. CLIMATE DYNAMICS 2018; 52:6953-6967. [PMID: 31178628 PMCID: PMC6534512 DOI: 10.1007/s00382-018-4555-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 11/26/2018] [Indexed: 06/09/2023]
Abstract
Despite the fact that the Little Ice Age (LIA) is well documented for the European Alps, substantial uncertainties concerning the regional spatio-temporal patterns of temperature changes associated with the LIA still exist, especially for their eastern sector. Here we present a high-resolution (4-10 years) 700-year long mean July air temperature reconstruction based on subfossil chironomid assemblages from a remote lake in the Austrian Eastern Alps to gain further insights into the LIA climatic deterioration in the region. The record provides evidence for a prolonged period of predominantly cooler conditions during AD 1530-1920, broadly equivalent to the climatically defined LIA in Europe. The main LIA phase appears to have consisted of two cold time intervals divided by slightly warmer episodes in the second half of the 1600s. The most severe cooling occurred during the eighteenth century. The LIA temperature minimum about 1.5 °C below the long-term mean recorded in the mid-1780 s coincides with the strongest volcanic signal found in the Greenland ice cores over the past 700 years and may be, at least in part, a manifestation of cooling that followed the long-lasting AD 1783-1784 Laki eruption. A continuous warming trend is evident since ca AD 1890 (1.1 °C in 120 years). The chironomid-inferred temperatures show a clear correlation with the instrumental data and reveal a close agreement with paleotemperature evidence from regional high-elevation tree-ring chronologies. A considerable amount of the variability in the temperature record may be linked to changes in the North Atlantic Oscillation.
Collapse
Affiliation(s)
- Elena A. Ilyashuk
- Institute of Ecology, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Oliver Heiri
- Geoecology, Department of Environmental Sciences, University of Basel, Klingelbergstrasse 27, 4056 Basel, Switzerland
| | - Boris P. Ilyashuk
- Institute of Ecology, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institute for Alpine Environment, Eurac Research, Viale Druso 1, 39100 Bozen/Bolzano, Italy
| | - Karin A. Koinig
- Institute of Ecology, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institute for Alpine Environment, Eurac Research, Viale Druso 1, 39100 Bozen/Bolzano, Italy
| | - Roland Psenner
- Institute of Ecology, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institute for Alpine Environment, Eurac Research, Viale Druso 1, 39100 Bozen/Bolzano, Italy
| |
Collapse
|
31
|
Navarro L, Harvey AÉ, Ali A, Bergeron Y, Morin H. A Holocene landscape dynamic multiproxy reconstruction: How do interactions between fire and insect outbreaks shape an ecosystem over long time scales? PLoS One 2018; 13:e0204316. [PMID: 30278052 PMCID: PMC6168141 DOI: 10.1371/journal.pone.0204316] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 09/06/2018] [Indexed: 11/18/2022] Open
Abstract
At a multi-millennial scale, various disturbances shape boreal forest stand mosaics and the distribution of species. Despite the importance of such disturbances, there is a lack of studies focused on the long-term dynamics of spruce budworm (Choristoneura fumiferana (Clem.)) (SBW) outbreaks and the interaction of insect outbreaks and fire. Here, we combine macrocharcoal and plant macrofossils with a new proxy—lepidopteran scales—to describe the Holocene ecology around a boreal lake. Lepidopteran scales turned out to be a more robust proxy of insect outbreaks than the traditional proxies such as cephalic head capsules and feces. We identified 87 significant peaks in scale abundance over the last 10 000 years. These results indicate that SBW outbreaks were more frequent over the Holocene than suggested by previous studies. Charcoal accumulation rates match the established fire history in eastern Canada: a more fire-prone early and late Holocene and reduced fire frequency during the mid-Holocene. Although on occasion, both fire and insect outbreaks were coeval, our results show a generally inverse relationship between fire frequency and insect outbreaks over the Holocene.
Collapse
Affiliation(s)
- Lionel Navarro
- Département des Sciences fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada
- * E-mail:
| | - Anne-Élizabeth Harvey
- Département des Sciences fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada
| | - Adam Ali
- Institut des Sciences de l’Évolution, Montpellier, UMR 5554 CNRS-IRD-Université Montpellier-EPHE, Montpellier, France
| | - Yves Bergeron
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, boul. de l’Université, Rouyn-Noranda, Québec, Canada
| | - Hubert Morin
- Département des Sciences fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada
| |
Collapse
|
32
|
Intermediate foraging large herbivores maintain semi-open habitats in wilderness landscape simulations. Ecol Modell 2018. [DOI: 10.1016/j.ecolmodel.2018.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
33
|
Borehole temperature reconstructions reveal differences in past surface temperature trends for the permafrost in the Laptev Sea region, Russian Arctic. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s41063-018-0041-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
34
|
McGowan H, Callow JN, Soderholm J, McGrath G, Campbell M, Zhao JX. Global warming in the context of 2000 years of Australian alpine temperature and snow cover. Sci Rep 2018. [PMID: 29535348 PMCID: PMC5849736 DOI: 10.1038/s41598-018-22766-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Annual resolution reconstructions of alpine temperatures are rare, particularly for the Southern Hemisphere, while no snow cover reconstructions exist. These records are essential to place in context the impact of anthropogenic global warming against historical major natural climate events such as the Roman Warm Period (RWP), Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Here we show for a marginal alpine region of Australia using a carbon isotope speleothem reconstruction, warming over the past five decades has experienced equivalent magnitude of temperature change and snow cover decline to the RWP and MCA. The current rate of warming is unmatched for the past 2000 years and seasonal snow cover is at a minimum. On scales of several decades, mean maximum temperatures have undergone considerable change ≈ ± 0.8 °C highlighting local scale susceptibility to rapid temperature change, evidence of which is often masked in regional to hemisphere scale temperature reconstructions.
Collapse
Affiliation(s)
- Hamish McGowan
- Atmospheric Observations Research Group, School of Earth and Environmental Sciences, The University of Queensland, Brisbane, 4072, Australia.
| | - John Nikolaus Callow
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia
| | - Joshua Soderholm
- Atmospheric Observations Research Group, School of Earth and Environmental Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - Gavan McGrath
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia
| | - Micheline Campbell
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia
| | - Jian-Xin Zhao
- Radiogenic Isotope Facility, School of Earth and Environmental Sciences, The University of Queensland, St, Brisbane, 4072, Australia
| |
Collapse
|
35
|
The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature. CLIMATE 2018. [DOI: 10.3390/cli6010003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
36
|
Weaver JL, Pearce CI, Sjöblom R, McCloy JS, Miller M, Varga T, Arey BW, Conroy MA, Peeler DK, Koestler RJ, DePriest PT, Vicenzi EP, Hjärthner-Holdar E, Ogenhall E, Kruger AA. Pre-viking Swedish hillfort glass: A prospective long-term alteration analogue for vitrified nuclear waste. INTERNATIONAL JOURNAL OF APPLIED GLASS SCIENCE 2018; 9:10.1111/ijag.12351. [PMID: 31093322 PMCID: PMC6512990 DOI: 10.1111/ijag.12351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 03/07/2018] [Indexed: 06/09/2023]
Abstract
Models for long-term glass alteration are required to satisfy performance predictions of vitrified nuclear waste in various disposal scenarios. Durability parameters are usually extracted from short-term laboratory tests, and sometimes checked with long-term natural experiments on glasses, termed analogues. In this paper, a unique potential ancient glass analogue from Sweden is discussed. The hillfort glass found at Broborg represents a unique case study as a vitrified waste glass analogue to compare to Low Activity Waste glass to be emplaced in near surface conditions at Hanford (USA). Glasses at Broborg have similar and dissimilar compositions to LAW glasses, allowing the testing of long-term alteration of different glass chemistries. In addition, the environmental history of the site is reasonably well documented. Initial investigations on previously collected samples established methodologies for handling and characterizing these artifacts by laboratory methods while preserving their alteration layers and cultural context. Evidence of possible biologically influenced glass alteration, and differential alteration in the 2 types of glass found at the Broborg site is presented.
Collapse
Affiliation(s)
- Jamie L. Weaver
- National Institute of Standards and Technology, Gaithersburg, MD, USA
- Pacific Northwest National Laboratory, Richland, WA, USA
| | | | | | - John S. McCloy
- Pacific Northwest National Laboratory, Richland, WA, USA
- School of Materials and Mechanical Engineering, Washington State University, Pullman, WA, USA
| | - Micah Miller
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Tamas Varga
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Bruce W. Arey
- Pacific Northwest National Laboratory, Richland, WA, USA
| | | | | | - Robert J. Koestler
- Museum Conservation Institute, Smithsonian Institution, Suitland, MD, USA
| | - Paula T. DePriest
- Museum Conservation Institute, Smithsonian Institution, Suitland, MD, USA
| | - Edward P. Vicenzi
- Museum Conservation Institute, Smithsonian Institution, Suitland, MD, USA
| | - Eva Hjärthner-Holdar
- The Archaeologists, Geoarchaeological Laboratory, National Historical Museums (SHMM), Uppsala, Sweden
| | - Erik Ogenhall
- The Archaeologists, Geoarchaeological Laboratory, National Historical Museums (SHMM), Uppsala, Sweden
| | - Albert A. Kruger
- U.S. Department of Energy, Office of River Protection, Richland, WA, USA
| |
Collapse
|
37
|
Scale-dependent climatic drivers of human epidemics in ancient China. Proc Natl Acad Sci U S A 2017; 114:12970-12975. [PMID: 29109246 DOI: 10.1073/pnas.1706470114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A wide range of climate change-induced effects have been implicated in the prevalence of infectious diseases. Disentangling causes and consequences, however, remains particularly challenging at historical time scales, for which the quality and quantity of most of the available natural proxy archives and written documentary sources often decline. Here, we reconstruct the spatiotemporal occurrence patterns of human epidemics for large parts of China and most of the last two millennia. Cold and dry climate conditions indirectly increased the prevalence of epidemics through the influences of locusts and famines. Our results further reveal that low-frequency, long-term temperature trends mainly contributed to negative associations with epidemics, while positive associations of epidemics with droughts, floods, locusts, and famines mainly coincided with both higher and lower frequency temperature variations. Nevertheless, unstable relationships between human epidemics and temperature changes were observed on relatively smaller time scales. Our study suggests that an intertwined, direct, and indirect array of biological, ecological, and societal responses to different aspects of past climatic changes strongly depended on the frequency domain and study period chosen.
Collapse
|
38
|
Loisel J, MacDonald GM, Thomson MJ. Little Ice Age climatic erraticism as an analogue for future enhanced hydroclimatic variability across the American Southwest. PLoS One 2017; 12:e0186282. [PMID: 29036207 PMCID: PMC5643054 DOI: 10.1371/journal.pone.0186282] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/28/2017] [Indexed: 11/19/2022] Open
Abstract
The American Southwest has experienced a series of severe droughts interspersed with strong wet episodes over the past decades, prompting questions about future climate patterns and potential intensification of weather disruptions under warming conditions. Here we show that interannual hydroclimatic variability in this region has displayed a significant level of non-stationarity over the past millennium. Our tree ring-based analysis of past drought indicates that the Little Ice Age (LIA) experienced high interannual hydroclimatic variability, similar to projections for the 21st century. This is contrary to the Medieval Climate Anomaly (MCA), which had reduced variability and therefore may be misleading as an analog for 21st century warming, notwithstanding its warm (and arid) conditions. Given past non-stationarity, and particularly erratic LIA, a ‘warm LIA’ climate scenario for the coming century that combines high precipitation variability (similar to LIA conditions) with warm and dry conditions (similar to MCA conditions) represents a plausible situation that is supported by recent climate simulations. Our comparison of tree ring-based drought analysis and records from the tropical Pacific Ocean suggests that changing variability in El Niño Southern Oscillation (ENSO) explains much of the contrasting variances between the MCA and LIA conditions across the American Southwest. Greater ENSO variability for the 21st century could be induced by a decrease in meridional sea surface temperature gradient caused by increased greenhouse gas concentration, as shown by several recent climate modeling experiments. Overall, these results coupled with the paleo-record suggests that using the erratic LIA conditions as benchmarks for past hydroclimatic variability can be useful for developing future water-resource management and drought and flood hazard mitigation strategies in the Southwest.
Collapse
Affiliation(s)
- Julie Loisel
- Department of Geography, Texas A&M University, Eller O&M Building, College Station TX
- Institute of the Environment and Sustainability, University of California Los Angeles, La Kretz Hall, Los Angeles CA
- Department of Geography, University of California Los Angeles, Bunche Hall, Los Angeles CA
- * E-mail:
| | - Glen M. MacDonald
- Institute of the Environment and Sustainability, University of California Los Angeles, La Kretz Hall, Los Angeles CA
- Department of Geography, University of California Los Angeles, Bunche Hall, Los Angeles CA
| | - Marcus J. Thomson
- Department of Geography, University of California Los Angeles, Bunche Hall, Los Angeles CA
| |
Collapse
|
39
|
Zhao X, Ren B, Garber PA, Li X, Li M. Impacts of human activity and climate change on the distribution of snub-nosed monkeys in China during the past 2000 years. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12657] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Xumao Zhao
- Key Laboratory of Animal Ecology and Conservation Biology; Institute of Zoology; Chinese Academy of Sciences; Beijing China
- University of the Chinese Academy of Sciences; Beijing China
| | - Baoping Ren
- Key Laboratory of Animal Ecology and Conservation Biology; Institute of Zoology; Chinese Academy of Sciences; Beijing China
| | - Paul A. Garber
- Department of Anthropology and Program in Ecology and Evolutionary Biology; University of Illinois; Urbana IL USA
| | - Xinhai Li
- Key Laboratory of Animal Ecology and Conservation Biology; Institute of Zoology; Chinese Academy of Sciences; Beijing China
| | - Ming Li
- Key Laboratory of Animal Ecology and Conservation Biology; Institute of Zoology; Chinese Academy of Sciences; Beijing China
| |
Collapse
|
40
|
Disturbance-grazer-vegetation interactions maintain habitat diversity in mountain pasture-woodlands. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2017.06.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
41
|
Bezrukova EV, Amosova AA, Chubarov VM, Finkelshtein AL, Kulagina NV. Environmental changes in the northeast of the Buryat Republic during the Holocene post-Optimum: First results. CONTEMP PROBL ECOL+ 2017. [DOI: 10.1134/s1995425517040011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
42
|
Linear and non-linear responses of vegetation and soils to glacial-interglacial climate change in a Mediterranean refuge. Sci Rep 2017; 7:8121. [PMID: 28808336 PMCID: PMC5556017 DOI: 10.1038/s41598-017-08101-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 07/07/2017] [Indexed: 11/25/2022] Open
Abstract
The impact of past global climate change on local terrestrial ecosystems and their vegetation and soil organic matter (OM) pools is often non-linear and poorly constrained. To address this, we investigated the response of a temperate habitat influenced by global climate change in a key glacial refuge, Lake Ohrid (Albania, Macedonia). We applied independent geochemical and palynological proxies to a sedimentary archive from the lake over the penultimate glacial-interglacial transition (MIS 6–5) and the following interglacial (MIS 5e-c), targeting lake surface temperature as an indicator of regional climatic development and the supply of pollen and biomarkers from the vegetation and soil OM pools to determine local habitat response. Climate fluctuations strongly influenced the ecosystem, however, lake level controls the extent of terrace surfaces between the shoreline and mountain slopes and hence local vegetation, soil development and OM export to the lake sediments. There were two phases of transgressional soil erosion from terrace surfaces during lake-level rise in the MIS 6–5 transition that led to habitat loss for the locally dominant pine vegetation as the terraces drowned. Our observations confirm that catchment morphology plays a key role in providing refuges with low groundwater depth and stable soils during variable climate.
Collapse
|
43
|
Hari P, Aakala T, Hilasvuori E, Häkkinen R, Korhola A, Korpela M, Linkosalo T, Mäkinen H, Nikinmaa E, Nöjd P, Seppä H, Sulkava M, Terhivuo J, Tuomenvirta H, Weckström J, Hollmén J. Reliability of temperature signal in various climate indicators from northern Europe. PLoS One 2017; 12:e0180042. [PMID: 28662166 PMCID: PMC5491121 DOI: 10.1371/journal.pone.0180042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 06/08/2017] [Indexed: 11/21/2022] Open
Abstract
We collected relevant observational and measured annual-resolution time series dealing with climate in northern Europe, focusing in Finland. We analysed these series for the reliability of their temperature signal at annual and seasonal resolutions. Importantly, we analysed all of the indicators within the same statistical framework, which allows for their meaningful comparison. In this framework, we employed a cross-validation procedure designed to reduce the adverse effects of estimation bias that may inflate the reliability of various temperature indicators, especially when several indicators are used in a multiple regression model. In our data sets, timing of phenological observations and ice break-up were connected with spring, tree ring characteristics (width, density, carbon isotopic composition) with summer and ice formation with autumn temperatures. Baltic Sea ice extent and the duration of ice cover in different watercourses were good indicators of winter temperatures. Using combinations of various temperature indicator series resulted in reliable temperature signals for each of the four seasons, as well as a reliable annual temperature signal. The results hence demonstrated that we can obtain reliable temperature information over different seasons, using a careful selection of indicators, combining the results with regression analysis, and by determining the reliability of the obtained indicator.
Collapse
Affiliation(s)
- Pertti Hari
- University of Helsinki, Department of Forest Sciences, Helsinki, Finland
| | - Tuomas Aakala
- University of Helsinki, Department of Forest Sciences, Helsinki, Finland
- * E-mail:
| | - Emmi Hilasvuori
- Laboratory of Chronology, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Risto Häkkinen
- Natural Resources Institute Finland (Luke), Helsinki, Finland
| | - Atte Korhola
- University of Helsinki, Department of Environmental Sciences, Helsinki, Finland
| | - Mikko Korpela
- Aalto University, Department of Information and Computer Science, Aalto, Espoo, Finland
- University of Helsinki, Department of Geosciences and Geography, Helsinki, Finland
| | - Tapio Linkosalo
- Natural Resources Institute Finland (Luke), Helsinki, Finland
| | - Harri Mäkinen
- Natural Resources Institute Finland (Luke), Aalto, Espoo, Finland
| | - Eero Nikinmaa
- University of Helsinki, Department of Forest Sciences, Helsinki, Finland
| | - Pekka Nöjd
- Natural Resources Institute Finland (Luke), Aalto, Espoo, Finland
| | - Heikki Seppä
- University of Helsinki, Department of Geosciences and Geography, Helsinki, Finland
| | - Mika Sulkava
- Natural Resources Institute Finland (Luke) Statistical services, Helsinki, Finland
| | - Juhani Terhivuo
- University of Helsinki, Finnish Museum of Natural History, Helsinki, Finland
| | | | - Jan Weckström
- University of Helsinki, Department of Environmental Sciences, Helsinki, Finland
| | - Jaakko Hollmén
- Aalto University, Department of Information and Computer Science, Aalto, Espoo, Finland
| |
Collapse
|
44
|
Ling H, Zhang P, Guo B, Xu H, Ye M, Deng X. Negative feedback adjustment challenges reconstruction study from tree rings: A study case of response of Populus euphratica to river discontinuous flow and ecological water conveyance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 574:109-119. [PMID: 27639018 DOI: 10.1016/j.scitotenv.2016.09.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Revised: 09/05/2016] [Accepted: 09/06/2016] [Indexed: 06/06/2023]
Abstract
Drought stress changes the relationship between the growth of tree rings and variations in ambient temperature. However, it is not clear how the growth of trees changes in response to drought of varying intensities, especially in arid areas. Therefore, Tree rings were studied for 6years in Populus euphratica to assess the impacts of abrupt changes in environment on tree rings using the theories and methods in dendrohydrology, ecology and phytophysiology. The width of tree rings increased by 8.7% after ecological water conveyance downstream of Tarim River compared to that when the river water had been cut off. However, during intermediate drought, as the depth of the groundwater increases, the downward trend in the tree rings was reversed because of changes in the physiology of the tree. Therefore, the growth of tree rings shows a negative feedback to intermediate drought stress, an observation that challenges the homogenization theory of tree ring reconstruction based on the traditional methods. Owing to the time lag, the cumulative effect and the negative feedback between the growth of tree rings and drought stress, the reconstruction of past environment by studying the patterns of tree rings is often inaccurate. Our research sets out to verify the hypothesis that intermediate drought stress results in a negative feedback adjustment and thus to answers two scientific questions: (1) How does the negative feedback adjustment promote the growth of tree rings as a result of intermediate drought stress? (2) How does the negative feedback adjustment lower the accuracy with which the past is reconstructed based on tree rings? This research not only enriches the connotations of intermediate disturbance hypothesis and reconstruction theory of tree rings, but also provides a scientific basis for the conservation of desert riparian forests worldwide.
Collapse
Affiliation(s)
- Hongbo Ling
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences (CAS), Urumqi 830011, China
| | - Pei Zhang
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Department of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Bin Guo
- College of Geomatics, Shandong University of Science and Technology, Qingdao 266590, China
| | - Hailiang Xu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences (CAS), Urumqi 830011, China.
| | - Mao Ye
- School of Geography Science and Tourism, Xinjiang Normal University, Urumqi 830054, China
| | - Xiaoya Deng
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Department of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| |
Collapse
|
45
|
Reynolds DJ, Scourse JD, Halloran PR, Nederbragt AJ, Wanamaker AD, Butler PG, Richardson CA, Heinemeier J, Eiríksson J, Knudsen KL, Hall IR. Annually resolved North Atlantic marine climate over the last millennium. Nat Commun 2016; 7:13502. [PMID: 27922004 PMCID: PMC5150573 DOI: 10.1038/ncomms13502] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 10/10/2016] [Indexed: 11/24/2022] Open
Abstract
Owing to the lack of absolutely dated oceanographic information before the modern instrumental period, there is currently significant debate as to the role played by North Atlantic Ocean dynamics in previous climate transitions (for example, Medieval Climate Anomaly-Little Ice Age, MCA-LIA). Here we present analyses of a millennial-length, annually resolved and absolutely dated marine δ18O archive. We interpret our record of oxygen isotope ratios from the shells of the long-lived marine bivalve Arctica islandica (δ18O-shell), from the North Icelandic shelf, in relation to seawater density variability and demonstrate that solar and volcanic forcing coupled with ocean circulation dynamics are key drivers of climate variability over the last millennium. During the pre-industrial period (AD 1000–1800) variability in the sub-polar North Atlantic leads changes in Northern Hemisphere surface air temperatures at multi-decadal timescales, indicating that North Atlantic Ocean dynamics played an active role in modulating the response of the atmosphere to solar and volcanic forcing. A lack of annually resolved climate records from the marine archive limits our understanding of oceanic processes. Here, the authors present a millennial-length, annually-resolved and absolutely-dated marine δ18O record from the shells of marine bivalves and offer insight into North Atlantic climate dynamics.
Collapse
Affiliation(s)
- D J Reynolds
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - J D Scourse
- School of Ocean Sciences, College of Natural Science, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK
| | - P R Halloran
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK
| | - A J Nederbragt
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - A D Wanamaker
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa 50011-3212, USA
| | - P G Butler
- School of Ocean Sciences, College of Natural Science, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK
| | - C A Richardson
- School of Ocean Sciences, College of Natural Science, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK
| | - J Heinemeier
- Aarhus AMS Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - J Eiríksson
- Institute of Earth Sciences, University of Iceland, Askja, Sturlugata 7, IS-101 Reykjavík, Iceland
| | - K L Knudsen
- Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus C, Denmark
| | - I R Hall
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| |
Collapse
|
46
|
Xu L, Liu X, Wu L, Sun L, Zhao J, Chen L. Decline of recent seabirds inferred from a composite 1000-year record of population dynamics. Sci Rep 2016; 6:35191. [PMID: 27748366 PMCID: PMC5066250 DOI: 10.1038/srep35191] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/27/2016] [Indexed: 11/09/2022] Open
Abstract
Based on three ornithogenic sediment profiles and seabird subfossils therein from the Xisha Islands, South China Sea, the relative population size of seabirds over the past 1000 years was reconstructed using reflectance spectrum. Here we present an apparent increase and subsequent decline of seabirds on these islands in the South China Sea. Seabird populations peaked during the Little Ice Age (LIA, 1400-1850 AD), implying that the cool climate during the LIA appears to have been more favorable to seabirds on the Xisha Islands in the South China Sea. Climate change partly explains the recent decrease in seabird populations over the past 150 years, but the significant decline and almost complete disappearance thereof on most of the Xisha Islands is probably attributable to human disturbance. Our study reveals the increasing impact of anthropogenic activities on seabird population in recent times.
Collapse
Affiliation(s)
- Liqiang Xu
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China.,Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaodong Liu
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Libin Wu
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Liguang Sun
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jinjun Zhao
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
| | - Lin Chen
- Xisha Deep Sea Marine Environment Observation and Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sansha, Hainan 573199, China
| |
Collapse
|
47
|
Zheng Y, Shao X, Lu F, Li Y. February-May temperature reconstruction based on tree-ring widths of Abies fargesii from the Shennongjia area in central China. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2016; 60:1175-1181. [PMID: 26759230 DOI: 10.1007/s00484-015-1111-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 10/26/2015] [Accepted: 11/09/2015] [Indexed: 06/05/2023]
Abstract
February-May temperature strongly affects ecological processes and socio-economics in central China, yet its long-term variability has not been thoroughly assessed due to the shortness of instrumental records. In order to improve the understanding of the regularities of temperature variability in central China, in this study, we present a new tree-ring chronology from the Shengnongjia Mountains in central China which provides a valuable 245-year record of temperature variability. The reconstructed temperature correlated strongly with February-May mean temperature records of the Fangxian meteorological station from AD 1958 to AD 2011, and the derived reconstruction explained 44.5 % of the instrumental temperature variation during this period. The study shows that this region experienced three warm periods and two cool periods, i.e., the major warm periods occurred in AD 1783-1806, AD 1879-1909, and AD 1975 to the present, whereas the cool intervals occurred in AD 1807-1878 and AD 1910-1974. This reconstruction could aid in the evaluation of regional climate variability in subtropical China.
Collapse
Affiliation(s)
- Yonghong Zheng
- School of Resource and Environmental Sciences, Wuhan University, Wuhan, 430079, China.
| | - Xuemei Shao
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Fei Lu
- Hebei Provincial Environmental Scientific Research, Shijiazhuang, 050037, China
| | - Yan Li
- Meteorological Observation Center of CMA, Beijing, 10086, China
| |
Collapse
|
48
|
Peringer A, Gillet F, Rosenthal G, Stoicescu I, Pătru-Stupariu I, Stupariu MS, Buttler A. Landscape-scale simulation experiments test Romanian and Swiss management guidelines for mountain pasture-woodland habitat diversity. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2016.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
49
|
Baek C, Kwon Y. Bootstrap estimation of long-run variance under strong dependence. KOREAN JOURNAL OF APPLIED STATISTICS 2016. [DOI: 10.5351/kjas.2016.29.3.449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
50
|
Centennial-scale solar forcing of the South American Monsoon System recorded in stalagmites. Sci Rep 2016; 6:24762. [PMID: 27097590 PMCID: PMC4838851 DOI: 10.1038/srep24762] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/04/2016] [Indexed: 11/09/2022] Open
Abstract
The South American Monsoon System (SAMS) is generally considered to be highly sensitive to Northern Hemisphere (NH) temperature variations on multi-centennial timescales. The direct influence of solar forcing on moisture convergence in global monsoon systems on the other hand, while well explored in modeling studies, has hitherto not been documented in proxy data from the SAMS region. Hence little is known about the sensitivity of the SAMS to solar forcing over the past millennium and how it might compete or constructively interfere with NH temperature variations that occurred primarily in response to volcanic forcing. Here we present a new annually-resolved oxygen isotope record from a 1500-year long stalagmite recording past changes in precipitation in the hitherto unsampled core region of the SAMS. This record details how solar variability consistently modulated the strength of the SAMS on centennial time scales during the past 1500 years. Solar forcing, besides the previously recognized influence from NH temperature changes and associated Intertropical Convergence Zone (ITCZ) shifts, appears as a major driver affecting SAMS intensity at centennial time scales.
Collapse
|