As the Great Barrier Reef reels from successive devastating bleaching events, researchers are working to regenerate small areas with corals selected or manipulated for better heat tolerance.
Climate change is increasingly implicated in the decline of insect pollinator populations, which provide critical ecosystem services. Isolating its contribution from other co-occurring environmental stresses remains challenging yet crucial for informing conservation strategies and mitigating biodiversity losses. Here we compare predictions of ecologically suitable areas for European bumblebee species from 1901 to 2019 under factual and counterfactual scenarios to evaluate whether climate change has led to a loss of suitable habitat. Community-level ecological suitability was reduced by climate change across Europe by 5% on average and up to 19% locally, with pronounced declines in southern and lowland central regions. By contrast, in the Alpine and Boreal regions, habitat suitability gains at higher altitudes partially offset losses at lower latitudes and altitudes, resulting in minimal net changes. Our results demonstrate that climate change is reshaping the ecologically suitable areas for these key pollinators and represents a pervasive pressure on European wildlife. The authors consider factual and counterfactual scenarios to isolate the role of climate change in the decline of suitable habitats for European bumblebees (1901–2019). They show reductions of 5% on average, and up to 19% locally, with high-altitude gains partially offsetting losses.
The ‘double materiality’ framework helps guide financial policymakers in assessing the risks of climate change, but masks complex interactions within the financial system. I argue that effective policy requires more clarity on the underlying relationships and the links to specific mandates of different financial policymakers.
Leading European cities race to reach net-zero emissions, but residual emissions are tied to easier-to-abate sectors and temporary, land-intensive carbon removal for compensation. To keep climate neutrality credible and fair, policy must tighten expectations on cutting emissions and set clear rules for carbon removal and credits.
Rising atmospheric CO2 and climate change have generally enhanced plant water-use efficiency (WUE), yet the influence of fine particulate pollution (PM2.5) on this carbon–water coupling remains poorly understood. Drawing on a global database of tree-ring isotopes, eddy-covariance fluxes and satellite-derived vegetation metrics, here we show that PM2.5 exerts a predominantly negative influence on WUE across spatial scales. The magnitude of this effect varies geographically and is modulated by interactions among vegetation traits, pollution levels and climate, with forests and non-forests exhibiting distinct patterns. The WUE decline arises primarily from the PM2.5-induced suppression of photosynthesis rather than changes in evapotranspiration, due to reduced photosynthetically active radiation and carboxylation capacity. Current ecosystem models that omit aerosol processes fail to reproduce the observed PM2.5–WUE relation, which indicates that covarying climate drivers alone are insufficient to explain this effect. Our findings identify PM2.5 as an overlooked yet critical factor that weakens plant carbon–water coupling under climate change. The influence of fine particulate pollution (PM2.5) on plant water-use efficiency remains poorly understood. The authors highlight that PM2.5 exerts a primarily negative effect across scales due to asymmetric effects on photosynthesis and evapotranspiration.
Cities increasingly pledge net-zero emissions targets, but the robustness of their residual emissions strategies remains uncertain. We examine the approaches of 103 European cities aiming at net zero by 2030. Total residual emissions are 61.4 MtCO2e originating mostly from buildings and transport, with the median at 0.8 tCO2e per capita, indicating a rapid decarbonization process. All municipal strategies rely on temporary, land-based CO2 removal, then carbon credits (40%) and permanent CO2 removal (32%). We develop the residual emissions strategy robustness index to assess the robustness of compensation strategies, indicating that the current maturity is medium-low with notable geographical disparities. Although cities invest in options mapping and governance, little attention is paid to land availability, the potential of the urban fabric to become a distributed carbon sink, provisions against carbon reversals, monitoring, timing and quantification (estimates cover only 18% of total residual emissions). We also distil recommendations and best practices to address residual emissions.
The Atlantic Meridional Overturning Circulation (AMOC), a tipping element of the climate system, currently has an estimated global warming threshold for collapse of +4.0 °C (uncertainty range 1.4–8 °C). However, such a threshold may not be meaningful because AMOC stability depends on the rate of radiative forcing change, not a set temperature. Here we identify an AMOC stabilizing mechanism that operates on timescales slower than present-day warming rates. Slow forcing permits coherent adjustment of surface and interior ocean properties, supported by enhanced evaporation and reduced sea-ice extent, counteracting destabilizing feedbacks. Using a slow CO2 ramp (+0.5 ppm yr−1) climate model simulation, we explicitly demonstrate the AMOC remains stable up to +5.5 °C of global warming. By contrast, under faster CO2 ramps, the AMOC collapses at substantially lower warming levels (+2 °C). Our findings demonstrate rate-induced AMOC tipping and imply that limiting the rate of emissions is critical for reducing the risk of an AMOC collapse. Climate change is expected to alter oceanic circulation, with the Atlantic Meridional Overturning Circulation (AMOC) at risk of collapse. This work shows that the stability of the AMOC is dependent on the rate of atmospheric CO2 change rather than having a fixed threshold.
Heat extremes are intensifying under climate change, yet these events are traditionally identified using daily temperature metrics, which fail to capture the full dynamics of heat events. Here we present a global assessment of hourly heat extremes (HHEs) in summer, and show that HHEs are emerging worldwide and exhibit marked unequal exposure across regions and generations. Under a high-emissions scenario, global HHEs are projected to increase fourfold and their population exposure to grow sixfold by late century. Each hot day will gain about four hot hours, and a further three hot hours will occur on non-hot days, which daily metrics overlook. Low- and middle-income countries bear more than three-quarters of the current and future heat exposure, and successive generations, particularly in low-income countries, face much higher lifetime exposure than earlier cohorts. These findings underscore the urgent need for hourly-scale risk assessments, public preparedness and designing equitable strategies in a warming world. The authors quantify the global emergence of hourly heat extremes (HHEs), highlighting exposure overlooked by daily metrics. HHEs will increase fourfold by the end of the century under high emissions, with low- and middle-income countries, as well as successive generations, facing disproportionate exposure.
Although net negative emissions of carbon dioxide (CO2) are essential to meet climate targets, little is known about how declining atmospheric CO2 levels will affect ocean acidification. Here, by analysing the acidity ([H+]) and corrosivity to aragonite (ΩArag) in eight Earth system models that made simulations under rising then falling CO2 levels, we identify the Arctic as a hotspot for delayed reversibility of ocean acidification. Under falling CO2, Arctic surface waters remain comparatively more acidic, and aragonite-corrosive conditions (ΩArag < 1) persist until atmospheric CO2 drops ~120 ppm below the threshold at which they first appeared under rising CO2. This hysteresis arises from the erosion of the natural surface-layer deficit in dissolved inorganic carbon, initially maintained by sea ice limiting air–sea gas exchange and not fully restored as sea ice recovers during CO2 decline. Thus, the Arctic Ocean experiences not only the greatest acidification but also the most delayed benefits from negative emissions. Changes in the Earth system may persist long after atmospheric CO2 levels decline. This study examines ocean acidification and how it will persist in ocean regions globally, with the Arctic identified as the area that experiences relief from acidification the latest under negative emissions.
Montane tree species are undergoing accelerated elevational range shifts in response to climate warming, yet the mechanisms driving interspecific variation remain elusive. Here we show that hydraulic traits predict opposing biogeographic responses of montane trees to warming and drought. By integrating hemispheric-scale dendrochronological records from 45 species (121,743 individuals), global observations of elevational range shifts from 102 species and hydraulic trait data for 11 functional attributes, we demonstrate that climate-sensitive species tended to rapidly track warming into higher elevations, whereas taxa resistant to these stresses were poised to have expanded downslope. In addition, elevational dependencies in drought sensitivity changed over time for nearly one-third of the species, revealing dynamic reorganization of climate–growth relationships across mountain gradients. These findings establish leaf- and stem-level hydraulic traits as a fundamental predictor of range dynamics, providing a mechanistic basis for forecasting the reorganization of montane forests under continued climate change. The authors integrate dendrochronological records with range shifts to show that shifts in montane tree species are tightly linked to tree hydraulic properties. While climate-sensitive species track warming to higher elevations, stress-resistant species expand downslope.
Social media have become central to climate change communication, shaping how information circulates, how publics engage and who participates. We synthesize research about the prevalence and dominant forms of climate-related content on social media, as well as the documented effects of social media on attitudes, knowledge and behaviour, which exist but are context dependent and vary with platform affordances, governance regimes and sociopolitical conditions. We also examine how social media reshape the broader landscape of climate change communication by enabling outreach and diverse voices, while fostering fragmentation, ideological bias and misinformation, as well as marginalizing traditional media. Finally, we identify key gaps, including restricted data access, limited cross-regional research, and the underrepresentation of non-Western contexts and region-specific platforms, and call for an expanded, reflexive research agenda in future work. Social media have become an important arena for climate change communication. This Review synthesizes climate-related content on social media, its effects on climate attitudes, knowledge and behaviour, and its role in reshaping the broader communication landscape.
Social influence, which refers to how individuals and groups shape others’ attitudes and actions, plays a central role in encouraging climate-related behaviours. Here we synthesize insights from climate communication, social psychology and behavioural science to organize current evidence on how influence operates in the context of climate action. We structure this synthesis around four interacting dimensions: who is influencing, where influence is directed, how it occurs and which behaviours are targeted. Across these dimensions, we highlight strengths and gaps in the evidence, including the roles of different actors, modes of influence, and audience characteristics. We identify key priorities for future research, particularly the need to better understand how these elements interact in real-world contexts to support sustained climate action. Individuals and groups shape others’ attitudes and actions through social influence. This Perspective articulates a research agenda of social influence for climate action, synthesizes existing evidence and highlights its practical relevance for designing effective behavioural interventions.
Communication is essential for keeping communities safe when climate disasters occur. Here, we explore how disaster communication informs protective actions and examine five challenges: false information, exhaustion from repeated disasters, unequal access to information, polarized climate attitudes and mental health.
Assessing the status of adaptation is important to target support and determine priority gaps. Here I look back on an influential 2021 study that reported a systematic review of evidence of implemented human adaptation and consider how this underscored the imperative for greater policy action and spawned methodological advancements in how to track adaptation progress.
Global temperature change over long times after cessation of greenhouse gas emissions is not well constrained. Now, research shows a consistent global cooling, especially if negative CO2 emissions compensate for continued CH4 and N2O emissions.
