1
|
Aguiar W, Meissner KJ, Montenegro A, Prado L, Wainer I, Carlson AE, Mata MM. Magnitude of the 8.2 ka event freshwater forcing based on stable isotope modelling and comparison to future Greenland melting. Sci Rep 2021; 11:5473. [PMID: 33750824 PMCID: PMC7943769 DOI: 10.1038/s41598-021-84709-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 02/17/2021] [Indexed: 11/10/2022] Open
Abstract
The northern hemisphere experienced an abrupt cold event ~ 8200 years ago (the 8.2 ka event) that was triggered by the release of meltwater into the Labrador Sea, and resulting in a weakening of the poleward oceanic heat transport. Although this event has been considered a possible analogue for future ocean circulation changes due to the projected Greenland Ice Sheet (GIS) melting, large uncertainties in the amount and rate of freshwater released during the 8.2 ka event make such a comparison difficult. In this study, we compare sea surface temperatures and oxygen isotope ratios from 28 isotope-enabled model simulations with 35 paleoproxy records to constrain the meltwater released during the 8.2 ka event. Our results suggest that a combination of 5.3 m of meltwater in sea level rise equivalent (SLR) released over a thousand years, with a short intensification over ~ 130 years (an additional 2.2 m of equivalent SLR) due to routing of the Canadian river discharge, best reproduces the proxy anomalies. Our estimate is of the same order of magnitude as projected future GIS melting rates under the high emission scenario RCP8.5.
Collapse
Affiliation(s)
- Wilton Aguiar
- Laboratório de Estudos dos Oceanos e Clima, Instituto de Oceanografia, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil.
| | - Katrin J Meissner
- Climate Change Research Center and ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, Australia
| | - Alvaro Montenegro
- Department of Geography, The Ohio State University, Columbus, OH, 43210, USA
| | - Luciana Prado
- Instituto Oceanográfico, Universidade de São Paulo, São Paulo, 05508-120, Brazil.,Instituto de Geociências, Universidade de Brasília, Brasília, 70297-400, Brazil
| | - Ilana Wainer
- Instituto Oceanográfico, Universidade de São Paulo, São Paulo, 05508-120, Brazil
| | | | - Mauricio M Mata
- Laboratório de Estudos dos Oceanos e Clima, Instituto de Oceanografia, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil
| |
Collapse
|
2
|
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
|
3
|
Marine Biodiversity, Climate Change, and Governance of the Oceans. DIVERSITY-BASEL 2012. [DOI: 10.3390/d4020224] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
4
|
van den Broeke M, Bamber J, Ettema J, Rignot E, Schrama E, van de Berg WJ, van Meijgaard E, Velicogna I, Wouters B. Partitioning recent Greenland mass loss. Science 2010; 326:984-6. [PMID: 19965509 DOI: 10.1126/science.1178176] [Citation(s) in RCA: 693] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mass budget calculations, validated with satellite gravity observations [from the Gravity Recovery and Climate Experiment (GRACE) satellites], enable us to quantify the individual components of recent Greenland mass loss. The total 2000-2008 mass loss of approximately 1500 gigatons, equivalent to 0.46 millimeters per year of global sea level rise, is equally split between surface processes (runoff and precipitation) and ice dynamics. Without the moderating effects of increased snowfall and refreezing, post-1996 Greenland ice sheet mass losses would have been 100% higher. Since 2006, high summer melt rates have increased Greenland ice sheet mass loss to 273 gigatons per year (0.75 millimeters per year of equivalent sea level rise). The seasonal cycle in surface mass balance fully accounts for detrended GRACE mass variations, confirming insignificant subannual variation in ice sheet discharge.
Collapse
|
5
|
Abstract
Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion.
Collapse
Affiliation(s)
- Anny Cazenave
- Laboratoire d'etudes en géophysique et océanographie spatiales LEGOS-CNES, Observatoire Midi-Pyrénées.
| | | |
Collapse
|
6
|
Rockström J, Steffen W, Noone K, Persson A, Chapin FS, Lambin EF, Lenton TM, Scheffer M, Folke C, Schellnhuber HJ, Nykvist B, de Wit CA, Hughes T, van der Leeuw S, Rodhe H, Sörlin S, Snyder PK, Costanza R, Svedin U, Falkenmark M, Karlberg L, Corell RW, Fabry VJ, Hansen J, Walker B, Liverman D, Richardson K, Crutzen P, Foley JA. A safe operating space for humanity. Nature 2009; 461:472-5. [PMID: 19779433 DOI: 10.1038/461472a] [Citation(s) in RCA: 2103] [Impact Index Per Article: 140.2] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Johan Rockström
- Stockholm Resilience Centre, Stockholm University, Kräftriket 2B, 10691 Stockholm, Sweden
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
|
8
|
Rahmstorf S, Cazenave A, Church JA, Hansen JE, Keeling RF, Parker DE, Somerville RCJ. Recent climate observations compared to projections. Science 2007; 316:709. [PMID: 17272686 DOI: 10.1126/science.1136843] [Citation(s) in RCA: 451] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We present recent observed climate trends for carbon dioxide concentration, global mean air temperature, and global sea level, and we compare these trends to previous model projections as summarized in the 2001 assessment report of the Intergovernmental Panel on Climate Change (IPCC). The IPCC scenarios and projections start in the year 1990, which is also the base year of the Kyoto protocol, in which almost all industrialized nations accepted a binding commitment to reduce their greenhouse gas emissions. The data available for the period since 1990 raise concerns that the climate system, in particular sea level, may be responding more quickly to climate change than our current generation of models indicates.
Collapse
Affiliation(s)
- Stefan Rahmstorf
- Potsdam Institute for Climate Impact Research, 14482 Potsdam, Germany
| | | | | | | | | | | | | |
Collapse
|