Search for: "climate change"

Climate change has led to an alarming increase in the frequency and severity of wildfires worldwide. While it is known that amphibians have physiological characteristics that make them highly susceptible to fire, the specific impacts of wildfires on their symbiotic skin bacterial communities (i.e., bacteriomes) and infection by the deadly chytrid fungus, Batrachochytrium dendrobatidis, remain poorly understood. Here, we address this research gap by evaluating the effects of fire on the amphibian skin bacteriome and the subsequent risk of chytridiomycosis. We sampled the skin bacteriome of the Neotropical species Scinax squalirostris and Boana leptolineata in fire and control plots before and after experimental burnings. Fire was linked with a marked increase in bacteriome beta dispersion, a proxy for skin microbial dysbiosis, alongside a trend of increased pathogen loads. By shedding light on the effects of fire on amphibian skin bacteriomes, this study contributes to our broader understanding of the impacts of wildfires on vulnerable vertebrate species. 

Many regions of the planet have experienced an increase in fire activity in recent decades. Although such increases are consistent with warming and drying under continued climate change, the driving mechanisms remain uncertain. Here, we investigate the effects of increasing atmospheric carbon dioxide concentrations on future fire activity using seven Earth system models. Centered on the time of carbon dioxide doubling, the multi-model mean percent change in fire carbon emissions is 66.4 ± 38.8% (versus 1850 carbon dioxide concentrations, under fixed 1850 land-use conditions). A substantial increase is associated with enhanced vegetation growth due to carbon dioxide biogeochemical impacts at 60.1 ± 46.9%. In contrast, carbon dioxide radiative impacts, including warming and drying, yield a negligible response of fire carbon emissions at 1.7 ± 9.4%. Although model representation of fire processes remains uncertain, our results show the importance of vegetation dynamics to future increases in fire activity under increasing carbon dioxide, with potentially important policy implications.

 

Uptake and support of sustainable technologies that decrease greenhouse gas emissions are critical to mitigating climate change. Engagement in individual (e.g., eating less meat, electric car use) and collective (e.g., petition signing, donating money to environmental causes) sustainability behaviors may correlate with psychological factors including emotions, worry about climate change and natural hazards, and response efficacy. However, little research has explored these relationships in representative samples at high risk for climate-related hazard exposures (e.g., hurricanes, heatwaves, flooding). We assessed climate change-related sustainability behaviors in an ongoing, probability-based representative survey of 1479 Texas and Florida residents repeatedly exposed to climate-related hazards including hurricanes, heatwaves, flooding, and tornadoes. Controlling for demographics, behavior-related positive and negative emotions correlated with engagement in performing a greater number of collective-level sustainability behaviors (positive emotions: IRR = 2.06,p < .001; negative emotions: IRR = 1.46,p = .030).  However, negative emotions were mediated by natural hazard worry, which in turn was mediated by climate change worry. Positive emotions were mediated by response efficacy. Individual-level sustainability behaviors were associated with positive emotions (IRR = 1.18,p < .001), which were again mediated by response efficacy. In adjusted analyses unpacking the relationship between discrete emotions and sustainability behaviors, hope was associated with individual- and collective-level sustainability behaviors (allps < .05). Results suggest general climate change worry may be adaptive and that feelings of hope, relative to other emotions (both positive and negative), may help encourage sustainability behaviors that address climate change. Scalable interventions should explore leveraging these psychological experiences to promote uptake of sustainable technology-related behaviors more broadly.

 

The increase of tree canopy cover due to woody plant encroachment and tree plantations modifies both carbon and water dynamics. The tradeoffs between ecosystem net primary productivity (NPP) and water use with increasing tree cover in different climate conditions, particularly under future climate scenarios, are not well understood. Within the climate transition zone of the southern Great Plains, USA, we used the Soil and Water Assessment Tool+ (SWAT+) to investigate the combined impacts of increasing tree cover and climate change on carbon and water dynamics in three watersheds representing semiarid, subhumid, and humid climates. Model simulations incorporated two land use modifications (Baseline: existing tree cover; Forest +: increasing evergreen tree cover), in conjunction with two climate change projections (the RCP45 and the RCP85), spanning two time periods (historic: 1991-2020; future: 2070-2099). With climate change, the subhumid and humid watersheds exhibited a greater increase in evapotranspiration (ET) and a corresponding reduction in runoff compared to the semi-arid watershed, while the semi-arid and subhumid watersheds encountered pronounced losses in water availability for streams (>200 mm/year) due to increasing tree cover and climate change. With every 1 % increase in tree cover, both NPP and water use efficiency were projected to increase in all three watersheds under both climate change scenarios, with the subhumid watershed demonstrating the largest increases (>0.16 Mg/ha/year and 170 %, respectively). Increasing tree cover within grasslands, either through woody plant expansion or afforestation, boosts ecosystem NPP, particularly in subhumid regions. Nevertheless, this comes with a notable decrease in water resources, a concern made worse by future climate change. While afforestation offers the potential for greater NPP, it also brings heightened water scarcity concerns, highlighting the importance of tailoring carbon sequestration strategies within specific regions to mitigate unintended repercussions on water availability. 

Nearly 200 governments rely on the Intergovernmental Panel on Climate Change (IPCC) for scientific assessments of climate change. IPCC figures are important for conveying key findings, but can be difficult for policymakers and practitioners to understand. Best practices in graph design, summarized in the IPCC’s visual style guide, recommend conducting interviews with members of the target audience before finalizing figures. Therefore, we interviewed 20 policy makers and practitioners from different countries about three figures drafted for the second order draft of the summary for policymakers associated with IPCC’s Working Group III Sixth Assessment Report. Half were frequent users and half were occasional users of climate science, but similar comments emerged from both groups. The figures received a median rating of 3, on a scale from 1 (= not easy at all to understand) to 5 (= very easy to understand). Showing the caption did not always improve these ratings. Overall, two types of recommendations emerged. First, participants suggested focusing each figure on one key message for policymakers, and removing irrelevant details. For IPCC authors, this involves making hard choices about what to show in the figure and what to leave for the text. Additionally, participants suggested straightforward fixes such as using clear titles, labels, and captions that support the key message. Based on our findings, we present recommendations for the design of climate change figures, and examples of revised figures. These recommendations should be useful for the next round of IPCC reports, and for other organizations that communicate about climate science with policymakers and practitioners.

 

Habitat loss poses a major threat to global biodiversity. Many studies have explored the potential damages of deforestation to animal populations but few have considered trees as thermoregulatory microhabitats or addressed how tree loss might impact the fate of species under climate change. Using a biophysical approach, we explore how tree loss might affect semi-arboreal diurnal ectotherms (lizards) under current and projected climates. We find that tree loss can reduce lizard population growth by curtailing activity time and length of the activity season. Although climate change can generally promote population growth for lizards, deforestation can reverse these positive effects for 66% of simulated populations and further accelerate population declines for another 18%. Our research underscores the mechanistic link between tree availability and population survival and growth, thus advocating for forest conservation and the integration of biophysical modelling and microhabitat diversity into conservation strategies, particularly in the face of climate change. 

Teaching climate change is difficult. Its complexity spans many subjects, often taught disjointedly. Many climate change effects are not immediately observable, making it hard for students to connect to it personally.

This study investigates how we can spark high school students’ interest in learning about climate change using educational computer games.

We adopted a qualitative case research design to understand how games boost students’ drive and their role in motivating them. We selected a high school teacher and her eight students as our subjects, interviewing them in person. We analyzed their responses were using Keller’s ARCS Theory of Motivation Model and blending deductive and inductive methods.

The findings were encouraging: games positively impacted students’ interest in climate change. They transformed the learning atmosphere into a concentrated, captivating space where the content was seen as tough yet enjoyable. Moreover, the games helped students make real-world connections, enhancing their understanding and appreciation of the topic.

Educational games are a powerful tool in motivating students to learn about climate change science. Hence, educators should be ready to harness the games’ power to create immersive, fun, and stimulating learning environments.

 

Antarctica and its unique biodiversity are increasingly at risk from the effects of global climate change and other human influences. A significant recent element underpinning strategies for Antarctic conservation has been the development of a system of Antarctic Conservation Biogeographic Regions (ACBRs). The datasets supporting this classification are, however, dominated by eukaryotic taxa, with contributions from the bacterial domain restricted to Actinomycetota and Cyanobacteriota. Nevertheless, the ice-free areas of the Antarctic continent and the sub-Antarctic islands are dominated in terms of diversity by bacteria. Our study aims to generate a comprehensive phylogenetic dataset of Antarctic bacteria with wide geographical coverage on the continent and sub-Antarctic islands, to investigate whether bacterial diversity and distribution is reflected in the current ACBRs.

Soil bacterial diversity and community composition did not fully conform with the ACBR classification. Although 19% of the variability was explained by this classification, the largest differences in bacterial community composition were between the broader continental and maritime Antarctic regions, where a degree of structural overlapping within continental and maritime bacterial communities was apparent, not fully reflecting the division into separate ACBRs. Strong divergence in soil bacterial community composition was also apparent between the Antarctic/sub-Antarctic islands and the Antarctic mainland. Bacterial communities were partially shaped by bioclimatic conditions, with 28% of dominant genera showing habitat preferences connected to at least one of the bioclimatic variables included in our analyses. These genera were also reported as indicator taxa for the ACBRs.

Overall, our data indicate that the current ACBR subdivision of the Antarctic continent does not fully reflect bacterial distribution and diversity in Antarctica. We observed considerable overlap in the structure of soil bacterial communities within the maritime Antarctic region and within the continental Antarctic region. Our results also suggest that bacterial communities might be impacted by regional climatic and other environmental changes. The dataset developed in this study provides a comprehensive baseline that will provide a valuable tool for biodiversity conservation efforts on the continent. Further studies are clearly required, and we emphasize the need for more extensive campaigns to systematically sample and characterize Antarctic and sub-Antarctic soil microbial communities.

 

Strengthened by polar amplification, Arctic warming provides direct evidence for global climate change. This analysis shows how Arctic surface air temperature (SAT) extremes have changed throughout time. Using ERA5, we demonstrate a pan-Arctic (>60°N) significant upward SAT trend of +0.62°C decade⁻¹since 1979. Due to this warming, the warmest days of each month in the 1980s to 1990s would be considered average today, while the present coldest days would be regarded as normal in the 1980s to 1990s. Over 1979–2021, there was a 2°C (or 7%) reduction of pan-Arctic SAT seasonal cycle, which resulted in warming of the cold SAT extremes by a factor of 2 relative to the SAT trend and dampened trends of the warm SAT extremes by roughly 25%. Since 1979, autumn has seen the strongest increasing trends in daily maximum and minimum temperatures, as well as counts of days with SAT above the 90th percentile and decreasing trends in counts of days with SAT below the 10th percentile, consistent with rapid Arctic sea ice decline and enhanced air–ocean heat fluxes. The modulated SAT seasonal signal has a significant impact on the timing of extremely strong monthly cold and warm spells. The dampening of the SAT seasonal fluctuations is likely to continue to increase as more sea ice melts and upper-ocean warming persists. As a result, the Arctic winter cold SAT extremes may continue to exhibit a faster rate of change than that of the summer warm SAT extremes as the Arctic continues to warm.

As a result of global warming, the Arctic Ocean’s sea ice is receding, exposing more and more areas to air–sea interactions. This reduces the range of seasonal changes in Arctic surface air temperatures (SAT). Since 1979, the reduced seasonal SAT signal has decreased the trend of warm SAT extremes by 25% over the background warming trend and doubled the trend of cold SAT extremes relative to SAT trends. A substantial number of warm and cold spells would not have been identified as exceptional if the reduction of the Arctic SAT seasonal amplitudes had not been taken into account. As the Arctic continues to warm and sea ice continues to diminish, seasonal SAT fluctuations will become more dampened, with the rate of decreasing winter SAT extremes exceeding the rate of increasing summer SAT extremes.

 

There is a cross‐sectoral push among conservationists to simultaneously mitigate biodiversity loss and climate change, especially as the latter increasingly threatens the former. Growing evidence demonstrates that animals can have substantial impacts on carbon cycling. As such, there are increasing calls to use animal conservation and rewilding to dually overcome biodiversity loss and mitigate climate change.

Specifically, trophic rewilding—which involves restoring intact animal communities, functional roles and trophic structure within food webs, and natural ecosystem processes—utilizes a rewilding framework to simultaneously support biodiversity conservation and carbon capture and storage. Trophic rewilding is a complex conservation approach to mitigating climate change, involving accurate estimations of baseline conditions and continuous monitoring of carbon cycling and species impacts within a system. It is also predicated on garnering social support for both the reintroduction and monitoring of a species, and obtaining the animals themselves.

We are excited by the growing interest in this potential, but emphasize that a species' net impact on ecosystem carbon dynamics is context‐dependent. Caution is required whenever biodiversity conservation (including rewilding), climate change mitigation, and human welfare do not readily align. Hence—similar to other nature‐based solutions—these burgeoning efforts must avoid sweeping generalizations.

To bolster successful trophic rewilding, we highlight a range of social and ecological context dependencies that can vary outcomes in a rewilded carbon cycle and provide ethical considerations for successful implementation.

We conclude with an overview of the available technology to predict and monitor progress toward both biodiversity and climate mitigation goals.

Read the freePlain Language Summaryfor this article on the Journal blog.