Climate change favours large seasonal loss of Arctic ozone

Stacking Machine Learning Models Empowered High Time-Height-Resolved Ozone Profiling from the Ground to the Stratopause Based on MAX-DOAS Observation

Ozone (O3) profiles are crucial for comprehending the intricate interplay among O3 sources, sinks, and transport. However, conventional O3 monitoring approaches often suffer from limitations such as low spatiotemporal resolution, high cost, and cumbersome procedures. Here, we propose a novel approach that combines multiaxis differential optical absorption spectroscopy (MAX-DOAS) and machine learning (ML) technology. This approach allows the retrieval of O3 profiles with exceptionally high temporal resolution at the minute level and vertical resolution reaching the hundred-meter scale. The ML models are trained using parameters obtained from radiative transfer modeling, MAX-DOAS observations, and a reanalysis data set. To enhance the accuracy of retrieving the aqueous phosphorus from O3, we employ a stacking approach in constructing ML models. The retrieved MAX-DOAS O3 profiles are compared to data from an in situ instrument, lidar, and satellite observation, demonstrating a high level of consistency. The total error of this approach is estimated to be within 25%. On balance, this study is the first ground-based passive remote sensing of high time-height-resolved O3 distribution from ground to the stratopause (0-60 km). It opens up new avenues for enhancing our understanding of the dynamics of O3 in atmospheric environments. Moreover, the cost-effective and portable MAX-DOAS combined with this versatile profiling approach enables the potential for stereoscopic observations of various trace gases across multiple platforms.

Warming exacerbates the impacts of ultraviolet radiation in temperate diatoms but alleviates the effect on polar species

Under global change scenarios, the sea surface temperature is increasing steadily along with other changes to oceanic environments. Consequently, marine diatoms are influenced by multiple ocean global change drivers. We hypothesized that temperature rise mediates the responses of polar and temperate diatoms to UV radiation (UVR) to different extents, and exposed the temperate centric diatoms, Thalassiosira weissflogii and Skeletonema costatum, and a polar pennate diatom Entomoneis sp., to warming (+5°C) for 10 days, then performed short-term incubations under different radiation treatments with or without UVR. The effective quantum yields of the three diatoms were stable during exposure to PAR, but decreased when exposed to PAR + UVR, leading to significant UV-induced inhibition, which was 3% and 9%, respectively, for T. weissflogii and S. costatum under ambient temperature but increased to 12% and 17%, respectively, in the cells acclimated to the warming treatment. In contrast, UVR induced much higher inhibition, by about 45%, in the polar diatom Entomoneis sp. at ambient temperature, and the warming treatment alleviated the UV-induced inhibition, which dropped to 36%. The growth rates were significantly inhibited by UVR in S. costatum under the warming treatment and in Entomoneis sp. under ambient temperature, while there was no significant effect for T. weissflogii. Our results indicate that the polar diatom was more sensitive to UVR though warming could alleviate its impact, whereas the temperate diatoms were less sensitive to UVR but warming exacerbated its impacts, implying that diatoms living in different regions may exhibit differential responses to global changes.

CRISPR-Cas-mediated unfolded protein response control for enhancing plant stress resistance

Plants consistently encounter environmental stresses that negatively affect their growth and development. To mitigate these challenges, plants have developed a range of adaptive strategies, including the unfolded protein response (UPR), which enables them to manage endoplasmic reticulum (ER) stress resulting from various adverse conditions. The CRISPR-Cas system has emerged as a powerful tool for plant biotechnology, with the potential to improve plant tolerance and resistance to biotic and abiotic stresses, as well as enhance crop productivity and quality by targeting specific genes, including those related to the UPR. This review highlights recent advancements in UPR signaling pathways and CRISPR-Cas technology, with a particular focus on the use of CRISPR-Cas in studying plant UPR. We also explore prospective applications of CRISPR-Cas in engineering UPR-related genes for crop improvement. The integration of CRISPR-Cas technology into plant biotechnology holds the promise to revolutionize agriculture by producing crops with enhanced resistance to environmental stresses, increased productivity, and improved quality traits.

Impact of climate change on non-communicable diseases caused by altered UV radiation

Background

UV radiation can cause serious skin and eye diseases, especially cancers. UV-related skin cancer incidences have been increasing for decades. The determining factor for this development is the individual UV exposure. Climate change-induced changes in atmospheric factors can influence individual UV exposure.

Methods

On the basis of a topic-specific literature research, a review paper was prepared and supplemented by as yet unpublished results of the authors' own studies. The need for scientific research and development is formulated as well as primary prevention recommendations.

Results

Climate change alters the factors influencing UV irradiance and annual UV dose in Germany. First evaluations of satellite data for Germany show an increase in mean peak UV irradiance and annual UV dose for the last decade compared to the last three decades.

Conclusions

The climate change-related influences on individual UV exposure and the associated individual disease incidence cannot yet be reliably predicted due to considerable uncertainties. However, the current UV-related burden of disease already requires primary preventive measures to prevent UV-related diseases.

Changes in tropospheric air quality related to the protection of stratospheric ozone in a changing climate

Ultraviolet (UV) radiation drives the net production of tropospheric ozone (O3) and a large fraction of particulate matter (PM) including sulfate, nitrate, and secondary organic aerosols. Ground-level O3 and PM are detrimental to human health, leading to several million premature deaths per year globally, and have adverse effects on plants and the yields of crops. The Montreal Protocol has prevented large increases in UV radiation that would have had major impacts on air quality. Future scenarios in which stratospheric O3 returns to 1980 values or even exceeds them (the so-called super-recovery) will tend to ameliorate urban ground-level O3 slightly but worsen it in rural areas. Furthermore, recovery of stratospheric O3 is expected to increase the amount of O3 transported into the troposphere by meteorological processes that are sensitive to climate change. UV radiation also generates hydroxyl radicals (OH) that control the amounts of many environmentally important chemicals in the atmosphere including some greenhouse gases, e.g., methane (CH4), and some short-lived ozone-depleting substances (ODSs). Recent modeling studies have shown that the increases in UV radiation associated with the depletion of stratospheric ozone over 1980-2020 have contributed a small increase (~ 3%) to the globally averaged concentrations of OH. Replacements for ODSs include chemicals that react with OH radicals, hence preventing the transport of these chemicals to the stratosphere. Some of these chemicals, e.g., hydrofluorocarbons that are currently being phased out, and hydrofluoroolefins now used increasingly, decompose into products whose fate in the environment warrants further investigation. One such product, trifluoroacetic acid (TFA), has no obvious pathway of degradation and might accumulate in some water bodies, but is unlikely to cause adverse effects out to 2100.

Dependence of column ozone on future ODSs and GHGs in the variability of 500-ensemble members

State-of-the-art chemistry-climate models (CCMs) have indicated that a future decrease in ozone-depleting substances (ODSs) combined with an increase in greenhouse gases (GHGs) would increase the column ozone amount in most regions except the tropics and Antarctic. However, large Arctic ozone losses have occurred at a frequency of approximately once per decade since the 1990s (1997, 2011 and 2020), despite the ODS concentration peaking in the mid-1990s. To understand this, CCMs were used to conduct 24 experiments with ODS and GHG concentrations set based on predicted values for future years; each experiment consisted of 500-member ensembles. The 50 ensemble members with the lowest column ozone in the mid- and high latitudes of the Northern Hemisphere showed a clear ODS dependence associated with low temperatures and a strong westerly zonal mean zonal wind. Even with high GHG concentrations, several ensemble members showed extremely low spring column ozone in the Arctic when ODS concentration remained above the 1980-1985 level. Hence, ODS concentrations should be reduced to avoid large ozone losses in the presence of a stable Arctic polar vortex. The average of the lowest 50 members indicates that GHG increase towards the end of the twenty-first century will not cause worse Arctic ozone depletion.

A machine learning approach to analyse ozone concentration in metropolitan area of Lima, Peru

The main objective of this study is to model the concentration of ozone in the winter season on air quality through machine learning algorithms, detecting its impact on population health. The study area involves four monitoring stations: Ate, San Borja, Santa Anita and Campo de Marte, all located in Metropolitan Lima during the years 2017, 2018 and 2019. Exploratory, correlational and predictive approaches are presented. The exploratory results showed that ATE is the station with the highest prevalence of ozone pollution. Likewise, in an hourly scale analysis, the pollution peaks were reported at 00:00 and 14:00. Finally, the machine learning models that showed the best predictive capacity for adjusting the ozone concentration were the linear regression and support vector machine.

Recyclable, UV-Blocking, and Radiative Cooling Multifunctional Composite Membranes

It is well known that UV radiation can cause human health problems and that energy consumption can lead to human survival problems. Here, we prepared a composite membrane that can block UV radiation as well as reduce energy consumption. Carbon dots (CDs) and acrylates were prepared from xylose and epoxidized soybean oil as biomass feedstocks, respectively, and the composite membrane was prepared by a self-assembly strategy. The first layer of the membrane is composed of CDs and epoxy resin. Its main function is not only to weaken UV rays and the aggregation-induced quenching effect of CDs but also to reduce the absorption of UV rays by the second layer of the membrane. The second layer consists of barium sulfate (BaSO₄) and acrylate. Compared to TiO₂ (3.2 eV), BaSO₄ (∼6 eV) has a higher electronic band gap, which reduces the absorption of UV light by the membrane. The composite membrane exhibits excellent UV-blocking and radiative cooling performance, shielding 99% of UV rays. In addition, the membrane can reduce 4.4 °C in radiative cooling tests, achieving a good cooling effect. Finally, the recyclability of the BaSO₄/acrylate membrane is discussed, and 95% recovery rate provides sustainable utilization of the membrane. The composite membrane is expected to be popularized and used in low latitudes and areas with high temperature and high UV radiation near the equator.

Differential regulation of flower transpiration during abiotic stress in annual plants

Heat waves occurring during droughts can have a devastating impact on yield, especially if they happen during the flowering and seed set stages of the crop cycle. Global warming and climate change are driving an alarming increase in the frequency and intensity of combined drought and heat stress episodes, critically threatening global food security. Because high temperature is detrimental to reproductive processes, essential for plant yield, we measured the inner temperature, transpiration, sepal stomatal aperture, hormone concentrations and transcriptomic response of closed soybean flowers developing on plants subjected to a combination of drought and heat stress. Here, we report that, during a combination of drought and heat stress, soybean plants prioritize transpiration through flowers over transpiration through leaves by opening their flower stomata, while keeping their leaf stomata closed. This acclimation strategy, termed 'differential transpiration', lowers flower inner temperature by about 2-3°C, protecting reproductive processes at the expense of vegetative tissues. Manipulating stomatal regulation, stomatal size and/or stomatal density of flowers could serve as a viable strategy to enhance the yield of different crops and mitigate some of the current and future impacts of global warming and climate change on agriculture.

The MicroClimate Screen - A microscale climate exposure system for assessing the effect of CO2, temperature and UV on marine microalgae

Global warming and anthropogenic activities are changing the ocean, inducing profound impacts on marine life and ecosystems from changing physical and chemical factors in and above the water column. Rising surface temperatures, ocean acidification, and seasonal variations in UV radiation (UVR), modulated by water clarity and sea-ice extent, affect life cycles of the marine food-web, and directly or indirectly also the global carbon fixation. Diatoms, pelagic microalgae that are responsible for 40% of the marine productivity, have limited capability to avoid exposure to changing ocean conditions, and hence, highly relevant for model studies of the influence of climate change on growth and productivity in the marine environment. A plate-based high-throughput exposure system was constructed to assess the biological effects from relevant climate change factors on the diatom Skeletonema pseudocostatum, conducted as a chronic toxicity tests over 72 h periods. The exposure system consisted of a micro-climate unit and a light-exposure unit, enabling accurate regulation of pCO₂, temperature, UVR and photosynthetic active radiation (PAR). Changes in physical factors, including pH, dissolved inorganic carbon (DIC), total alkalinity (TA), temperature and salinity in the medium, as well as reduction in growth were characterised to demonstrate performance of the micro exposure system. The results demonstrate that the exposure system successfully simulated ocean acidification and could maintain stable temperature (CV < 3%), PAR and UVR irradiance (CV < 8%). Growth inhibition responses were typically dose-dependent and verified that the micro-exposure system could be used to assess effects and adaptions to climate-relevant stressors.

Responses of Arctic sea ice to stratospheric ozone depletion

The Arctic has experienced several extreme springtime stratospheric ozone depletion events over the past four decades, particularly in 1997, 2011 and 2020. However, the impact of this stratospheric ozone depletion on the climate system remains poorly understood. Here we show that the stratospheric ozone depletion causes significant reductions in the sea ice concentration (SIC) and the sea ice thickness (SIT) over the Kara Sea, Laptev Sea and East Siberian Sea from spring to summer. This is partially caused by enhanced ice transport from Barents-Kara Sea and East Siberian Sea to the Fram Strait, which is induced by a strengthened and longer lived polar vortex associated with stratospheric ozone depletion. Additionally, cloud longwave radiation and surface albedo feedbacks enhance the melting of Arctic sea ice, particularly along the coast of the Eurasian continent. This study highlights the need for realistic representation of stratosphere-troposphere interactions in order to accurately predict Arctic sea ice loss.

Reprogramming of Plant Central Metabolism in Response to Abiotic Stresses: A Metabolomics View

Abiotic stresses rewire plant central metabolism to maintain metabolic and energy homeostasis. Metabolites involved in the plant central metabolic network serve as a hub for regulating carbon and energy metabolism under various stress conditions. In this review, we introduce recent metabolomics techniques used to investigate the dynamics of metabolic responses to abiotic stresses and analyze the trend of publications in this field. We provide an updated overview of the changing patterns in central metabolic pathways related to the metabolic responses to common stresses, including flooding, drought, cold, heat, and salinity. We extensively review the common and unique metabolic changes in central metabolism in response to major abiotic stresses. Finally, we discuss the challenges and some emerging insights in the future application of metabolomics to study plant responses to abiotic stresses.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2021

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth’s surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1–67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.

Developing climate-resilient crops: improving plant tolerance to stress combination

Global warming and climate change are driving an alarming increase in the frequency and intensity of different abiotic stresses, such as droughts, heat waves, cold snaps, and flooding, negatively affecting crop yields and causing food shortages. Climate change is also altering the composition and behavior of different insect and pathogen populations adding to yield losses worldwide. Additional constraints to agriculture are caused by the increasing amounts of human-generated pollutants, as well as the negative impact of climate change on soil microbiomes. Although in the laboratory, we are trained to study the impact of individual stress conditions on plants, in the field many stresses, pollutants, and pests could simultaneously or sequentially affect plants, causing conditions of stress combination. Because climate change is expected to increase the frequency and intensity of such stress combination events (e.g., heat waves combined with drought, flooding, or other abiotic stresses, pollutants, and/or pathogens), a concentrated effort is needed to study how stress combination is affecting crops. This need is particularly critical, as many studies have shown that the response of plants to stress combination is unique and cannot be predicted from simply studying each of the different stresses that are part of the stress combination. Strategies to enhance crop tolerance to a particular stress may therefore fail to enhance tolerance to this specific stress, when combined with other factors. Here we review recent studies of stress combinations in different plants and propose new approaches and avenues for the development of stress combination- and climate change-resilient crops.

Arctic Stratosphere Circulation Changes in the 21st Century in Simulations of INM CM5

Simulations of Institute of Numerical Mathematics (INM) coupled climate model 5th version for the period from 2015 to 2100 under moderate (SSP2-4.5) and severe (SSP5-8.5) scenarios of greenhouse gases growth are analyzed to investigate changes of Arctic polar stratospheric vortex, planetary wave propagation, Sudden Stratospheric Warming frequency, Final Warming dates, and meridional circulation. Strengthening of wave activity propagation and a stationary planetary wave number 1 in the middle and upper stratosphere, acceleration of meridional circulation, an increase of winter mean polar stratospheric volume (Vpsc) and strengthening of Arctic stratosphere interannual variability after the middle of 21st century, especially under a severe scenario, were revealed. March monthly values of Vpsc in some winters could be about two times more than observed ones in the Arctic stratosphere in the spring of 2011 and 2020, which in turn could lead to large ozone layer destruction. Composite analysis shows that “warm” winters with the least winter mean Vpsc values are characterized by strengthening of wave activity propagation from the troposphere into the stratosphere in December but weaker propagation in January–February in comparison with winters having the largest Vpsc values.

Effects of UV Radiation on the Chlorophyte Micromonas polaris Host-Virus Interactions and MpoV-45T Virus Infectivity

Polar seas are under threat of enhanced UV-radiation as well as increasing shipping activities. Considering the ecological importance of marine viruses, it is timely to study the impact of UV-AB on Arctic phytoplankton host-virus interactions and also test the efficacy of ballast water (BW) UV-C treatment on virus infectivity. This study examined the effects of: (i) ecologically relevant doses of UV-AB radiation on Micromonas polaris RCC2258 and its virus MpoV-45T, and (ii) UV-C radiation (doses 25-800 mJ cm-2) on MpoV-45T and other temperate algal viruses. Total UV-AB exposure was 6, 12, 28 and 48 h (during the light periods, over 72 h total). Strongest reduction in algal growth and photosynthetic efficiency occurred for 28 and 48 h UV-AB treatments, and consequently the virus production rates and burst sizes were reduced by more than half (compared with PAR-only controls). For the shorter UV-AB exposed cultures, negative effects by UV (especially Fv/Fm) were overcome without impacting virus proliferation. To obtain the BW desired log-4 reduction in virus infectivity, a UV-C dose of at least 400 mJ cm-2 was needed for MpoV-45T and the temperate algal viruses. This is higher than the commonly used dose of 300 mJ cm-2 in BW treatment.