Warming Scenarios Research Articles

Heating up the roof of the world: tracing the impacts of in-situ warming on carbon cycle in alpine grasslands on the Tibetan Plateau.

Climate warming may induce substantial changes in the ecosystem carbon cycle, particularly for those climate-sensitive regions, such as alpine grasslands on the Tibetan Plateau. By synthesizing findings from in-situ warming experiments, this review elucidates the mechanisms underlying the impacts of experimental warming on carbon cycle dynamics within these ecosystems. Generally, alterations in vegetation structure and prolonged growing season favor strategies for enhanced ecosystem carbon sequestration under warming conditions. Whilst warming modifies soil microbial communities and their carbon-related functions, its effects on soil carbon release fall behind the increased vegetation carbon uptake. Despite the fact that no significant accumulation of soil carbon stock has been detected upon warming, notable changes in its fractions indicate potential shifts in carbon stability. Future studies should prioritize deep soil carbon dynamics, the interactions of carbon, nitrogen, and phosphorus cycles under warming scenarios, and the underlying biological mechanisms behind these responses. Furthermore, the integration of long-term warming experiments with Earth system models is essential for reducing the uncertainties of model predictions regarding future carbon-climate feedback in these climate-sensitive ecosystems.

Warming Diminishes the Day-Night Discrepancy in the Apparent Temperature Sensitivity of Ecosystem Respiration.

Understanding the sensitivity of ecosystem respiration (ER) to increasing temperature is crucial to predict how the terrestrial carbon sink responds to a warming climate. The temperature sensitivity of ER may vary on a diurnal basis but is poorly understood due to the paucity of observational sites documenting real ER during daytime at a global scale. Here, we used an improved flux partitioning approach to estimate the apparent temperature sensitivity of ER during the daytime (E0,day) and nighttime (E0,night) derived from multiyear observations of 189 FLUXNET sites. Our results demonstrated that E0,night is significantly higher than E0,day across all biomes, with significant seasonal variations in the day-night discrepancy in the temperature sensitivity of ER (ΔE0 = E0,night/E0,day) except for evergreen broadleaf forest and savannas. Such seasonal variations in ΔE0 mainly result from the effect of temperature and the seasonal amplitude of NDVI. We predict that future warming will decrease ΔE0 due to the reduced E0,night by the end of the century in most regions. Moreover, we further find that disregarding the ΔE0 leads to an overestimation of annual ER by 10~80% globally. Thus, our study highlights that the divergent temperature dependencies between day- and nighttime ER should be incorporated into Earth system models to improve predictions of carbon-climate change feedback under future warming scenarios.

Effects of Increasing Temperature on Bacterial Community Diversity in Mixed Stands of Artemisia argyi and Solidago canadensis in Eastern China.

Global climate change and invasive plants significantly impact biodiversity and ecosystem functions. This study focuses on the effects of progressive warming on microbial communities within the Solidago canadensis invasion community, simulated through six stages of invasion progression, from minimal to dominant S. canadensis presence alongside native Artemisia argyi, in bulk soils collected from a natural habitat and cultivated under controlled greenhouse conditions. Utilizing high-throughput sequencing and microbial community analysis on 72 samples collected from the S. canadensis invasion community, the shifts in soil microbiota under varying warming scenarios were investigated (+0 °C, +1.15 °C and +1.86 °C). We observed significant shifts in invasion community soil bacteria in response to warming, with Acidobacteria, Actinobacteria, and others showing distinct responses between baseline and warmed conditions, while groups like Chlorobi and Cyanobacteria only differed significantly at higher temperature extremes. The random forests algorithm identified 14 taxa as biomarkers and a model was established to correlate S. canadensis invasion community soil microbiota with progressive warming. Co-occurrence network analysis revealed that moderate warming enhances microbial connectivity and the presence of a super-generalist, ASV 1160. However, further warming disrupts these networks by eliminating key generalists, revealing a potential reduction in network stability and diversity. These findings illuminate the dynamic responses of microbes in S. canadensis invasion community soil to varying temperature regimes, suggesting a model for successional dynamics and offering a deeper comprehension of microbial community shifts amid climatic fluctuations. This study delineates how warming significantly reshapes the soil microbial composition, potentially impacting S. canadensis's invasion success unfavorably, thereby highlighting the importance of considering microbial dynamics in ecological management.

Stronger Westerly Wind Bursts in a Warming Climate: The Effects of the Pacific Warming Pattern, the Madden–Julian Oscillation, and Tropical Cyclones

Abstract Westerly wind bursts (WWBs) in the western–central equatorial Pacific are critical in El Niño–Southern Oscillation (ENSO) dynamics. Understanding how they may change with global warming has important implications for future projections of El Niño. In this study, we investigate how the enhanced eastern equatorial Pacific warming pattern, emerging in future climate projections, can influence WWB characteristics in an atmospheric general circulation model, CAM6. Changes in three main factors affecting WWBs—El Niño-conditions mean westerly wind stress anomalies, the Madden–Julian oscillation (MJO), and tropical cyclones (TCs)—are analyzed. We find that during El Niño onset (December–April), the WWB wind stress intensity remains largely unchanged but WWBs shift westward by about 20° of longitude. In contrast, during El Niño development (May–November), the WWB intensity increases by 41% or 79% in two warming scenarios considered [shared socioeconomic pathways (SSP5-8.5) and SSP2-4.5, respectively], which is mainly caused by a higher frequency of TC occurrence in the central tropical Pacific within 15°N/S. Further, we find that westerly wind speed anomalies associated with El Niño and the MJO also increase during El Niño development. However, as trade winds weaken in the central-eastern equatorial Pacific, the mean strength of the resulting westerly wind stress anomalies does not change much, and no significant eastward shift of WWBs is observed. Thus, our atmospheric model simulations suggest a strong TC-driven increase in WWB wind stress anomalies during El Niño development and hence a more important role of TCs in WWB generation, which in a coupled system could lead to stronger ENSO events, enhanced TC–ENSO coupling, and even greater intensification of WWBs.

Measuring butterfly persistence in the face of deep uncertainty: a case study using the regal fritillary

Scientists have documented effects of climate and land use change across a range butterfly species. However, incorporating future climate and land use change into butterfly conservation plans is a difficult task. These difficulties arise mainly from assumptions that future processes are the same as past processes (stationarity) and because scientists cannot reliably predict the future (deep uncertainty). In this case study, I used land use and climate change scenarios to compare possible futures for the regal fritillary, a grassland butterfly in the central United States. My analysis indicated that climate and land use change have the potential to influence species persistence, but that climate change has the larger effect. Moderate warming scenarios may improve the possibility of persistence, whereas extreme warming reduces this possibility. My analysis demonstrates the importance of considering nonstationarity and alternative plausible futures in butterfly conservation planning.

Historical and Future Asymmetry of ENSO Teleconnections with Extremes

Abstract El Niño–Southern Oscillation (ENSO) is the dominant source of climate variability globally. Many of the most devastating impacts of ENSO are felt through extremes. Here, we present and describe a spatially complete global synthesis of extreme temperature and precipitation relationships with ENSO. We also investigate how these relationships evolve under a future warming scenario under high greenhouse gas emissions using 14 models from phase 6 of Coupled Model Intercomparison Project (CMIP6) ensemble. First, we demonstrate that models broadly capture observed ENSO teleconnections to mean and extreme climate using the Twentieth Century Reanalysis, version 3 (20CRv3). The models project that more regions will experience an amplification of the historical ENSO teleconnection with mean temperature and precipitation than a dampening under a high-emission climate scenario. The response of the ENSO teleconnection with extremes is very similar to the mean response, with even larger changes in some regions. Hence, regions that are predicted to experience an amplification of the ENSO teleconnection under future warming can also expect a comparable amplification in the intensity of extremes. Furthermore, models that suggest greater amplification of ENSO amplitude also tend to exhibit greater intensification of mean and extreme teleconnections. Future changes in regional climate variability may be better constrained if changes in ENSO itself are better understood.

Sensitivity of the future evolution of the Wilkes Subglacial Basin ice sheet to grounding-line melt parameterizations

Abstract. Projections of Antarctic Ice Sheet mass loss and therefore global sea level rise are hugely uncertain, partly due to how mass loss of the ice sheet occurs at the grounding line. The Wilkes Subglacial Basin (WSB), a vast region of the East Antarctic Ice Sheet, is thought to be particularly vulnerable to deglaciation under future climate warming scenarios. However, future projections of ice loss, driven by grounding-line migration, are known to be sensitive to the parameterization of ocean-induced basal melt of the floating ice shelves and, specifically, to the adjacent grounding line – termed grounding-line melt parameterizations (GLMPs). This study investigates future ice sheet dynamics in the WSB with respect to four GLMPs under both the upper and lower bounds of climate warming scenarios from the present to 2500, with different model resolutions, ice shelf melt parameterizations (ISMPs) and choices of sliding relationships. The variation in these GLMPs determines the distribution and the amount of melt applied in the finite-element assembly procedure on partially grounded elements (i.e. elements containing the grounding line). Our findings indicate that the GLMPs significantly affect both the trigger timings of tipping points and the overall magnitude of ice mass loss. We conclude that applying full melting to the partially grounded elements, which causes melting on the grounded side of the grounding line, should be avoided under all circumstances due to its poor numerical convergence and substantial overestimation of ice mass loss. We recommend preferring options that depend on the specific model context, by either (1) not applying any melt immediately adjacent to the grounding line or (2) employing a sub-element parameterization.

Fungi that are medically relevant to humans and their prospect in a global warming scenario

Fungi that are medically relevant to humans and their prospect in a global warming scenario

Warming promotes expansion of a key demersal fishing resource of the western Mediterranean

Climate change is affecting marine ecosystems altering the distribution and abundance of organisms, with implications for fisheries and food security. This warming-induced reshuffle in species abundance could bring threats and opportunities to the fisheries, but needs to be assessed to promote effective actions and to foster resilience. We analyzed the density and distribution patterns of deep-sea rose shrimp (Parapenaeus longirostris), as well as identified the main environmental have identified the environmental drivers shaping its habitat along the western Mediterranean (Iberian Peninsula) during the period 2001–2020. Using spatial distribution models developed concurrently with an ensemble of four Regional Climate Models (RCMs), we have projected the density of this species during the next century under two climate scenarios (RCP4.5 and RCP8.5). Bathymetry and sea bottom temperature drove the density of the species, leading to a marked northward expansion during the last two decades. Our results projected an increase in its distribution and especially in density throughout the area along the 21st century, mirroring the effect of global warming. Consequently, the most distant period (i.e. 2100s) and the warmest scenario (RCP8.5) presented also the highest densities and low internal variability of the ensemble. We discussed the power of assessing uncertainties using a RCM ensemble, particularly under complex oceanographic features, to bring robust information for an effective scientific advice to fisheries management.

Nitrogen regulated reactive oxygen species metabolism of leaf and grain under elevated temperature during the grain-filling stage to stabilize rice substance accumulation

Rational additional nitrogen is an important agronomic measure to cope with the adverse effects of warming on rice production. However, the mechanism by which nitrogen mitigated the adverse impact of substance accumulation due to elevated temperature is poorly clarified. Therefore, in this study, a field warming experiment during grain filling and 60 kg·ha−1 of additional nitrogen was established. Under elevated temperature, panicle temperature was higher and increased more substantially than leaf temperature. However, nitrogen application did not significantly reduce the leaf, panicle, and canopy temperatures. Additional nitrogen under elevated temperature delayed the decline of chlorophyll, maintained leaf photosynthesis, and prolonged grain-filling period to alleviate the decrease of starch due to warming. Hydrogen peroxide (H2O2) was sensitive to elevated temperature in leaves and grains. However, application of nitrogen under elevated temperature improved the activity of antioxidant enzymes to mitigate the increase of H2O2, resulting in a 30.31 % and 45.33 % decrease of H2O2 in leaves and grains compared to elevated temperature, respectively. Elevated temperature promoted the expression of heat-responsive genes, especially HSP16.9 and HSP26.7, which were consistently increased in response to warming at 5–30d after flowering. In addition, the expression of HSP16.9 at 5d and 10d after flowering and HSP26.7 at 10d after flowering was further increased with nitrogen application under elevated temperature. Therefore, HSP may be the key regulator of grain response to warming with additional nitrogen under elevated temperature. In conclusion, the relevant results revealed the physiological mechanism of nitrogen to guarantee substance accumulation and provided new ideas for cultivation measures to protect against the likely scenario of global warming.

CARBON CAPTURE, USAGE AND STORAGE

Carbon Capture, Usage and Storage – in short CCUS, is not a new term in the current industrial environment. It is being discussed widely at all industrial forums, across all countries, big or small, to control pollution to ensure a healthy and happy life for all. There have been attempts and studies over last 50 years to capture carbon dioxide from the environment to avoid pollution and control global warming scenario. Many technologies have been in use for carbon capture, across the globe, some in large scale and others confined to local areas. It is expensive but very much essential – it is a goal set by WHO/UNO/European Commission – to clean the environment off CO2 gases, use it for alternative purposes or store it for future action. According to International Energy Agency (IEA), we must capture around 100 billion tons of CO2 by 2060 to meet International Global Warming and Energy goals. It is a huge goal and is a very expensive goal to achieve. All big countries who impact the environment in a huge way through their industries shall come forward for a collaboration to prepare a robust plan, pump-in money, monitor and control the processes, to achieve the goal. There is an estimate that US emitted around 5,1 mln t of CO2 in 2019 whereas Global estimate emitted around 33 mln t. These are very huge numbers and hence Global monitoring is very essential to control emission and safe storage and disposal. It is important to understand that Carbon Capture (CC), Carbon Capture and Use (CCU) and Carbon Capture and Storage (CCS) are three different terms. CC, CCU and CCS are combinedly termed as CCUS. CC is to capture carbon from various sources – fuel gas, fossil fuels, petroleum products, flares from refineries and power plants etc. Usage of the captured carbon in the form of carbon dioxide (CO2) is CCU and this is an important long-term vision by any government to ensure it is being used meaningful to avoid negative impact on climate. CCS is storage of the captured carbon quickly so that it does not impact the environment as a greenhouse gas and at the same time, it can be used later. Another term which is frequently used is Net Zero CO2. It is defined as follows: Any CO2 released into the atmosphere from a human activity shall be balanced by an equivalent amount being removed, either by nature-based solutions (including afforestation, reforestation or other changes in land use) or technological solutions that stores CO2 captured directly or indirectly, permanently. Net Zero CO2 is very important, unless this is achieved, CCUS goal cannot be achieved to control climate change. This write-up provides an insight into the following topics:  What is CCUS?  Why is it important?  Steps to CCUS;  CAPEX and OPEX involved.

Projected future changes in extreme precipitation over China under stratospheric aerosol intervention in the UKESM1 climate model

Abstract. Extreme precipitation events are linked to severe economic losses and casualties in China every year; hence, exploring the potential mitigation strategies to minimize these events and their changes in frequency and intensity under global warming is of importance, particularly for the populous subregions. In addition to global warming scenarios, this study examines the effects of the potential deployment of stratospheric aerosol injection (SAI) on hydrological extremes in China based on the SAI simulations (G6sulfur) of the Geoengineering Model Intercomparison Project (GeoMIP) by the UK Earth System Model (UKESM1) simulations. G6sulfur is compared with simulations of the future climate under two different emission scenarios (SSP5-8.5 and SSP2-4.5) and a reduction in the solar constant (G6solar) to understand the effect of SAI on extreme precipitation patterns. The results show that under global warming scenarios, precipitation and extreme wet climate events during 2071–2100 are projected to increase relative to the control period (1981–2010) across all the subregions in China. Extreme drought events show a projected increase in southern China. The G6sulfur and G6solar experiments show statistically similar results to those under SSP2-4.5 in extreme precipitation intensities of China in UKESM1. These results are encouraging. The efficacy of SAI in decreasing extreme precipitation events and consecutive wet days is more pronounced than that of G6solar when compared to SSP2-4.5. While both G6sulfur and G6solar show drying at high-latitude regions, which is consistent with our understanding of the spin-down of the hydrological cycle under SRM. Given the limitations of the current model and the small ensemble size, and considering that the hydrological effects are less beneficial than those indicated for temperature, it is recommended that further, more comprehensive research be performed, including using multiple models, to better understand these impacts.

Temperature alters antioxidant status and induces cell damage in the Amazonian fish tambaqui

Since Amazonian fish live close to their maximum thermal limits, this makes them vulnerable to the effects of global warming. The aim of this study was to evaluate the oxidative stress and antioxidant enzymatic and biochemical responses of the plasma, liver and muscle of tambaqui (Colossoma macropomum) exposed to a rising gradient of water temperature. One hundred and twenty (N = 120) juvenile tambaqui were exposed to four temperature levels, these being: the environmental temperature of the season (Tenv – 25.7–30 °C), 31 °C, 34 °C and 37 °C, following a completely randomized design with three replicates for a period of 60 days. Liver and muscle samples were used to determine the levels of the enzymes superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (GPx) and lipid peroxidation (LPO). Plasma levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. A histopathological damage assessment (HAI) was performed using liver samples and the results showed an increase in lipid peroxidation in the muscle and liver of animals kept at 37 °C in relation to other temperatures. Enzyme responses were tissue-specific in the liver and muscle. In the liver, the reduction of CAT, SOD and GPx levels of the animals was observed at 37 °C compared to those maintained at Tenv and SOD and GPx in relation to animals maintained at 31 and 34 °C. The GPx enzyme showed higher activity at 34 and 37 °C compared to the other evaluated temperatures. At 37 °C, plasma levels of ALT and AST were higher than the other temperatures evaluated, as well as an increase in histopathological damage. In this way, in a scenario of warming of the waters of the Amazon or even of the systems used for rearing of the species, the tambaqui will be able to cope with temperatures of up to 34 °C, without affecting its antioxidant capacity. However, at 37 °C, oxidative stress levels and increased liver damage suggest a reduction in antioxidant capacity due to tissue impairment of the organ and general loss of animal performance as it approaches the upper thermal limit of the species.

Metabolic balance of a marine neritic copepod under chronic and acute warming scenarios

We investigated the impact of sublethal thermal stress on physiological rates of the copepod Paracartia grani, and explored the influence of previous thermal history on this response. The copepods, originally reared at 19 °C, were raised for 23 generations at 22 °C and 25 °C, and posteriorly exposed for 7-d to stress temperature (28 °C). The copepod acclimation capacity was assessed by comparing metabolic balance at 28 °C against their respective rearing temperatures. There was an inverse relationship between rearing temperature and body size and carbon content for the reared copepod lines. Weight-specific rates, except respiration, increased with rearing temperature, whereas per capita rate differences were levelled, partly due to differences in copepod size. Heat stress impact, as weight-specific rate fold-change, appeared inversely related to rearing temperature. Carbon gains were overall sufficient and slightly in excess to account for carbon losses. Gross-growth efficiency across warming scenarios was conserved, emphasizing resilience to environmental change. Our findings underscore the importance of considering the species' thermal history when predicting the response of copepod populations to climate change associated phenomena such as gradual slow ocean warming or heatwave events.

Environmental Drivers of the Divergence of Harveyi Clade Pathogens with Distinctive Virulence Gene Profiles.

Fish and shellfish pathogens of the Harveyi clade of the Vibrio genus cause significant losses to aquaculture yields and profits, with some of them also causing infections in humans. The present study aimed to evaluate the presence of Harveyi clade fish and shellfish pathogens and their possible diversification in response to environmental drivers in southeastern USA waters. The presence and abundance of potential pathogens were evaluated via the detection and quantitation of six Harveyi-clade-specific virulence genes (toxR, luxR, srp, vhha, vhh, and vhp; VGs) in environmental DNA with clade-specific primers. The environmental DNA was obtained from water and sediments collected from three Georgia (USA) cultured clam and wild oyster grounds. In sediments, the VG concentrations were, on average, three orders of magnitude higher than those in water. The most and least frequently detected VGs were vhp and toxR, respectively. In water, the VGs split into two groups based on their seasonal trends. The first group, composed of luxR, vhp, vhha, and vhh, peaked in August and remained at lower concentrations throughout the duration of the study. The second group, composed of toxR and srp, peaked in June and disappeared between July and December. The first group revealed a high adaptation of their carriers to an increase in temperature, tolerance to a wide range of pH, and a positive correlation with salinity up to 25 ppt. The second group of VGs demonstrated a lower adaptation of their carriers to temperature and negative correlations with pH, salinity, potential water density, conductivity, and dissolved solids but a positive correlation with turbidity. No such trends were observed in sediments. These data reveal the role of VGs in the adaptability of the Harveyi clade pathogens to environmental parameters, causing their diversification and possibly their stratification into different ecological niches due to changes in water temperature, acidity, salinity, and turbidity. This diversification and stratification may lead to further speciation and the emergence of new pathogens of this clade. Our data urge further monitoring of the presence and diversification of Harveyi clade pathogens in a global warming scenario.

Flowering seasonality and airborne pollen recent trends in Sierra de las Nieves, the southernmost National Park in continental Spain

Sierra de las Nieves is the southernmost National Park in continental Spain and, in a global warming scenario, it is important to determine the impacts of climatic variations on the vegetation, with special relevance to their reproductive cycles. The flowering seasonality and intensity of the dominant anemophilous species usually reflect the response of the vegetation to climate variations, which can be monitored through the atmospheric pollen concentrations. In this study, airborne pollen was analysed for 6 years (2018–2023). A pollen calendar was elaborated to show the flowering seasonality and intensity of the dominant anemophilous taxa. Spring was the season with the highest airborne pollen diversity and intensity, Quercus being the pollen type with the highest concentrations. We observed that weather conditions influenced the presence of airborne pollen. Precipitation and relative humidity reduce pollen concentrations, while temperature rises increase them during the pre-peak period and reduce them during the post-peak. Wind dynamics play different roles depending on the pollen type considered given the heterogeneous distribution of the pollen emission sources. Significant advances were detected in the start date of the main pollen season of Quercus and Olea, as well as in the peak date of Quercus. On the contrary, other taxa such as Pinus or Poaceae did not show any trend. This brings to the fore that the responses to climatic variations may differ from one taxon to another, a continuous study in natural areas being required for detecting possible changes in the observed trends.

Increase in insurance losses caused by North Atlantic hurricanes in a warmer climate

North Atlantic hurricanes are a major driver of property losses in the United States and a critical peril for the reinsurance industry globally. We leverage insurance loss data and stochastic modeling to investigate the impacts of projected changes in hurricane climatology on the insurance industry, for +2 °C and +4 °C warming scenarios. We find that, relative to the historical baseline 1950-2022, expected changes in wind speed and rainfall may increase hurricane losses by 5% −15% (+2 °C) and 10% − 30% (+4 °C), with greater impacts at lower return periods than in the tail. The historical 100-year loss event may therefore be exceeded on average every 80 years (+2 °C) and 70 years (+4 °C). The expected changes in average annual loss are projected to be 10% (+2 °C) and 15% (+4 °C), with the largest relative increase attributable to precipitation-induced losses. Under the extreme SSP5-8.5 scenario, the expected loss inflation due to climate change is thus on the order of 0.5% per annum.

Estimating the temperature sensitivity of rice (Oryza sativa L.) yield and its components in China using the CERES-Rice model

The effects of temperature changes on rice (Oryza sativa L.) yield and its components have been widely documented. However, most existing studies are based on small-scale, short-term field experiments, with few assessing these effects on a large scale or over long periods. Here, the calibrated Crop Environment Resource Synthesis (CERES)-Rice model was used for numerical simulations over six climate regions in the major rice cultivation areas of China for the period of 1989–2018. The simulated results were used to estimate the temperature sensitivity of rice yield with a panel model in each climate region, and the yield sensitivity was then decomposed into the temperature sensitivity of three components: panicle number per unit area (Pan_no), filled grain number per panicle (Grain_no), and grain weight (Grainwt). Results indicated that rice yield exhibited negative temperature sensitivity across all climate regions, driven primarily by the temperature sensitivity of Grain_no in most regions. Additionally, Grainwt did not vary with temperature in all regions. Further analysis suggested that yield, Pan_no, and Grain_no were more sensitive to high temperature degree days (HDD) than to growing degree days (GDD). Under the warmer scenarios, HDD increase played a dominant role in the reduction of Grain_no, while the joint effect of GDD and HDD resulted in an increased Pan_no in most regions. However, the negative effect of temperature on Grain_no outweighed its positive effect on Pan_no, leading to a decline in yield. This study provides insight for understanding the temperature response of rice yield and its components and will be beneficial for developing targeted adaptations to ensure rice sustainable production under global warming.

Agricultural innovation for climate change: limited but positive impacts of commercialized drought-tolerant corn

Abstract The extent to which new technologies can countervail the risks posed by climate change is a critical element for designing adaptation strategies. This study uses new experimental data spanning 17 US states from 2008 to 2023 to examine the potential impact of recently commercialized drought tolerant (DT) traits on both yield and yield resilience in US corn production. We find that there is no yield advantage for DT hybrids under average weather conditions, but they improve yield resilience, particularly with respect to precipitation. These effects are spatially heterogeneous, such that DT has a positive yield impact in the droughty, western US, but a small, or even negative, impact in the central and eastern US. In addition, the presence of DT reduces yield variance and kurtosis, and increases skewness, all of which imply a reduction in yield risk. Using the statistical model estimates, we project the impact of DT on corn yields under future climate conditions obtained from 20 general circulation models with two representative concentration pathways. The projected ensemble means of yield gains are 6.34 bu/acre and 5.39 bu/acre under moderate and extreme warming scenarios, respectively, by the mid-twenty-first century. These gains compensate for 23% and 13.5% of total yield loss due to climate change. Our results indicate that current commercial DT hybrids reduce yield risk, improve resilience with respect to precipitation, and have the potential to offer moderate benefits under climate change warming scenarios.

Genomics-Informed Range Predictions Under Global Warming Reveal Reduced Adaptive Diversity Whilst Buffering Range Shifts for a Marine Snail.

Understanding the genetic basis of local adaptation in thermal performance is useful for predicting species distribution shifts under anthropogenic climate change. Many species are distributed across multiple biogeographic regions, and the uniquely adapted populations in each region may respond to future ocean warming with distinct distribution changes. In the present study, we investigated phylogeographic patterns, thermal sensitivity, and genetic differentiation in the intertidal snail Littorina brevicula along China's coast. Whole-genome sequencing results based on a newly assembled chromosome-level genome revealed two genetic lineages, with a north-south divergence that is linked to the thermal environment. Within each lineage, individuals could be further subdivided into genetic subgroups that differ at key genomic loci underpinning differences in upper heat tolerance. Heat stress drives adaptive divergence across multiple levels of organization, from the individual to the biogeographic level. Taking into account genetic diversity associated with variation in heat tolerance, a physiological species distribution model (pSDM) was applied to predict the distributions of the different genetic subgroups in response to climate change. Both northern and southern lineages were predicted to experience declines in habitat suitability under a 4°C future warming scenario, and that a genotypic subset of snails from the southern lineage may even be driven to extinction. These findings illustrate that even when a species' range is maintained, it can nonetheless experience a significant decrease in adaptive diversity as a result of climate change. The integrated approach presented here, which considered both physiological and adaptive genetic variation at the level of individuals within a biogeographical context, provided new insights into how marine species can respond to global warming.