Global warming has increased the probability of extreme climate events, with compound extreme events having more severe impacts on socioeconomics and the environment than individual extremes. Utilizing the Coupled Model Intercomparison Project Phase 6 (CMIP6), we predicted the spatiotemporal variations of compound extreme precipitation-high temperature events in China under three Shared Socioeconomic Pathways (SSPs) across two future periods, and analyzed the changes in exposed populations and identified influencing factors. From the result, we can see that, the CMIP6 effectively reproduces precipitation patterns but exhibits biases. The frequency of compound event rises across SSPs, especially under high radiative forcing, with a stronger long-term upward trend. Furthermore, the economically developed areas, notably China\'s southeastern coast and North China Plain, will be hotspots for frequent and intense compound extreme events, while other regions will see reduced exposure. Finally, in the long-term future (2070-2100), there is a noteworthy shift in population exposure to compound events, emphasizing the increasing influence of population factors over climate factors. This highlights the growing importance of interactions between population and climate in shaping exposure patterns.

UNASSIGNED: To identify the long-term spatiotemporal trend of ozone-related chronic obstructive pulmonary disease (COPD) burden by sex and country and to explore potential drivers.
UNASSIGNED: We retrieved data of ozone-related COPD death and disability adjusted life year (DALY) from the Global Burden of Disease 2019. We used a linear regression of natural logarithms of age-standardized rates (ASRs) with calendar year to examine the trends in ASRs and a panel regression to identify country-level factors associated with the trends.
UNASSIGNED: Global ozone-attributable COPD deaths increased from 117,114 to 208,342 among men and from 90,265 to 156,880 among women between 1990 and 2019. Although ASRs of ozone-related COPD death and DALY declined globally, they increased in low and low-middle Socio-demographic Index (SDI) regions, with faster rise in women. Elevated average maximum temperature was associated with higher ozone-attributable COPD burden, while more green space was associated with lower burden.
UNASSIGNED: More efforts are needed in low and low-middle SDI regions, particularly for women, to diminish inter-country inequality in ozone-attributable COPD. Global warming may exacerbate the burden. Expanding green space may mitigate the burden.

UNASSIGNED: Climate change, largely triggered by human-induced greenhouse gases (GHGs) emissions, seems unstoppable. There was a strong rebound of anthropogenic emissions of CO 2, the preponderant GHG in terms of contribution to global warming, around the world after the COVID-19 lockdown. Also, there is still no widely accepted international treaty on curbing the anthropogenic emissions of CH 4 and N 2O, the second and third predominant GHG, respectively, so far. Thereby, prima facie, in respect to mitigating climate change, currently, humans have no aces up their sleeves. It seems that current temperature rise is not high enough to take alarm until the occurrence of tipping point.
UNASSIGNED: Climate-related international treaties, such as 2016 Paris agreement, are compromises among conflicting geopolitical pressures. However, currently, the climate treaties show little mandatory binding force on the signatories who are able to violate and then get off scot-free, thus may end up like a nostrum. Throughout the European history, I find that the only way, if at all, to achieve the peace or obedience of a treaty is via balancing powers, embodied in Bismarck\'s Realpolitik of Germany and Richelieu\'s Raison d\'état of France. Similarly, the Chinese history in East Asia proved the significance of unadulterated ideological neutrality and Darwinian adaptability in the kaleidoscope of evolving circumstances in maintaining order and enforcement of international treaties through balancing the power of rivalries to constrain ever-recurring challengers for equilibrium.
UNASSIGNED: A successful policy needs to make a thorough analysis of all relevant factors to form a long-term strategic notion. Then, statesmen need to distill an array of nebulous, always contradictory options into a tenacious, controllable direction. Thereby, I suggest that, for better curbing global warming, climate agreements or climate club be incorporated into an overall geopolitical framework among the international communities.

Subsoil stores the majority of soil organic carbon (SOC), and plays a vital role in the global carbon cycle in terrestrial ecosystems and in regulating climate change. Response of SOC decomposition to temperature warming (TR) is a crucial parameter to predict SOC dynamics under global warming. However, it remains unknown how TR varies across the whole soil profile and responds to exogenous C and N inputs. To assess this, we designed a novel incubation system to measure SOC-derived CO2 efflux across the whole soil column (i.e., 60 cm length), allowing manual addition of 13C-labeled glucose and ammonium nitrate, and incubated it under ambient or warmed temperatures (+4 °C). We found that C addition significantly increased TR in 0-20 cm, 20-40 cm and 40-60 cm by 64.3 %, 68.1 % and 57.2 %, respectively. However, the combined addition of C and N decreased TR by 11.1 % - 15.3 % compared to without anything addition (CK) in the whole soil profile. The effect of N on TR ranged from -22.8 % to -40.4 % in the whole soil profile, and was significantly lower in topsoil than in subsoil. Furthermore, sole N addition significantly promoted TR compared to CK by 79.0 % and 94.7 % in 20-40 cm and 40-60 cm subsoil, only 9.8 % in 0-20 cm topsoil. These results together suggested that TR is sensitive to increasing C availability in the whole soil profile and increasing N availability in 20-60 cm subsoil. Random forest model indicated that soil enzyme activities (explained 21.3 % of the variance) and DOC (explained 11.1 % of the variance) dominantly governed TR in topsoil, but N availability displayed a predominant control of TR in subsoil. Overall, our results suggested that increased C and N availability under climate warming scenarios could further increase the risk of carbon loss especially in subsoil with substrate deficiency, but labile C (e.g., root exudation) input under climate warming and N enrichment could reduce SOC decomposition and benefit for C sequestration by decreasing TR.

Nicotiana tabacum L. (tobacco) has extremely high economic value, medicinal value, scientific research value and some other uses. Though it has been widely cultivated throughout the world, classification and change of its suitable habitats is not that clear, especially in the context of global warming. In order to achieve rational cultivation and sustainable development of tobacco, current (average from 1970-2000) and future (2070, average from 2061-2080) potential suitable habitats of Nicotiana tabacum L. were forecasted with MaxEnt model and ArcGIS platform based on 854 occurrence data and 22 environmental factors in this study. The results revealed that mean temperature of warmest quarter (bio10), annual precipitation (bio12), solar radiation in September (Srad9), and clay content (CLAY) were the four decisive environment variables for the distribution of Nicotiana tabacum L. Under current climate conditions, suitable habitats of Nicotiana tabacum L. were mainly distributed in south-central Europe, south-central North America, most parts of South America, central Africa, south and southeast Asia, and southeast coast of Australia, and only 13.7% of these areas were highly suitable. By the year 2070, suitable habitats under SSP1-2.6, SSP3-7.0, and SSP5-8.5 climate scenarios would all increase with the largest increase found under SSP3-7.0 scenario, while suitable habitats would reduce under SSP2-4.5 climate scenario. Globally, the center of mass of suitable habitats would migrate to southeast to varying degrees within Libya under four different climate scenarios. The emergence of new habitats and the disappearance of old habitats would all occur simultaneously under each climate scenario, and the specific changes in each area, combined with the prediction results under current climate conditions, will provide an important reference for the adjustment of agronomic practices and rational cultivation of Nicotiana tabacum L. both currently and in the future.

The global retreat of glaciers is dramatically altering mountain and high-latitude landscapes, with new ecosystems developing from apparently barren substrates1-4. The study of these emerging ecosystems is critical to understanding how climate change interacts with microhabitat and biotic communities and determines the future of ice-free terrains1,5. Here, using a comprehensive characterization of ecosystems (soil properties, microclimate, productivity and biodiversity by environmental DNA metabarcoding6) across 46 proglacial landscapes worldwide, we found that all the environmental properties change with time since glaciers retreated, and that temperature modulates the accumulation of soil nutrients. The richness of bacteria, fungi, plants and animals increases with time since deglaciation, but their temporal patterns differ. Microorganisms colonized most rapidly in the first decades after glacier retreat, whereas most macroorganisms took longer. Increased habitat suitability, growing complexity of biotic interactions and temporal colonization all contribute to the increase in biodiversity over time. These processes also modify community composition for all the groups of organisms. Plant communities show positive links with all other biodiversity components and have a key role in ecosystem development. These unifying patterns provide new insights into the early dynamics of deglaciated terrains and highlight the need for integrated surveillance of their multiple environmental properties5.

Understanding the alterations in soil microbial communities in response to climate warming and their controls over soil carbon (C) processes is crucial for projecting permafrost C-climate feedback. However, previous studies have mainly focused on microorganism-mediated soil C release, and little is known about whether and how climate warming affects microbial anabolism and the subsequent C input in permafrost regions. Here, based on a more than half-decade of in situ warming experiment, we show that compared with ambient control, warming significantly reduces microbial C use efficiency and enhances microbial network complexity, which promotes soil heterotrophic respiration. Meanwhile, microbial necromass markedly accumulates under warming likely due to preferential microbial decomposition of plant-derived C, further leading to the increase in mineral-associated organic C. Altogether, these results demonstrate dual roles of microbes in affecting soil C release and stabilization, implying that permafrost C-climate feedback would weaken over time with dampened response of microbial respiration and increased proportion of stable C pool.

Mycorrhiza is an important functional feature of plants, which plays a vital role in regulating plant phenology in response to environmental changes. However, the effect of mycorrhiza on plant phenological asymmetry in response to climate changes is still rarely reported. Based on a global database of mycorrhizal statuses (obligately mycorrhizal, OM and facultatively mycorrhizal, FM) and phenology, we demonstrated that mycorrhizas reduce the phenological mismatches between above- and below-ground plant responses to climate warming under OM status. The mismatch of above- and below-ground growing season length of FM plants to warming was as high as 10.65 days, 9.1925 days and 12.36 days in total, herbaceous and woody plants, respectively. The mismatch of growing season length of OM plants was only 2.12 days, -0.61 days and 7.64 days among plant groups, which was much lower than that of FM plants. Correlation analysis indicated that OM plants stabilized plant phenology by regulating the relationship between the start of the growing season and the length of the growing season. Path analysis found that herbaceous plants and woody plants reduced phenological mismatches by stabilizing below-ground and above-ground phenology, respectively. In exploring the effects of mycorrhizal status on early- or late-season phenophases, we found that different mycorrhizal statuses affected the response of early- or late-season phenophase to warming. OM promoted the advance of early-season phenophase, and FM promoted the delay of late-season phenophase among different plant groups. In different regions, OM and FM promoted the advance of early-season phenophase in temperate and boreal regions, respectively. Our results indicate that mycorrhizal status mediates plant phenological response to warming, so the potential effects of mycorrhizal status should be considered when studying plant phenology changes.

Given the increasing threat of economic downturns and global warming, the governments of developing countries urgently need effective measures that can both stimulate economic development and promote low-carbon transitions. As a widely accepted method for stimulating economic growth, the improvement of the business environment and its effect on economic activity have been fully discussed. However, little is known about whether and how the business environment affects the low-carbon transition. By leveraging city-level data from China, this paper exploits whether and through which channels a favorable business environment promotes a low-carbon transition. We find that improving the business environment has a positive impact on carbon efficiency. This relationship is verified to be robust through various alternative tests. Additionally, it is demonstrated that enhancing the business environment can increase carbon efficiency by promoting green technology progress and stimulating new firm entry. Heterogeneity analysis indicates that the positive effect of the business environment is pronounced for cities with intensive environmental regulation, sufficient environmentally targeted fiscal expenditure, and loose economic growth requirements. This paper reveals the unintentional environmental gains of business environment optimization and provides important insights into the low-carbon transition for developing economies.

Microbial necromass carbon (MNC) accounts for a large fraction of soil organic carbon (SOC) in terrestrial ecosystems. Yet our understanding of the fate of this large carbon pool under long-term warming is uncertain. Here, we show that 14 years of soil warming (+4°C) in a temperate forest resulted in a reduction in MNC by 11% (0-10 cm) and 33% (10-20 cm). Warming caused a decrease in the content of MNC due to a decline in microbial biomass carbon and reduced microbial carbon use efficiency. This reduction was primarily caused by warming-induced limitations in available soil phosphorus, which, in turn, constrained the production of microbial biomass. Conversely, warming increased the activity of soil extracellular enzymes, specifically N-acetylglucosaminidase and leucine aminopeptidase, which accelerated the decomposition of MNC. These findings collectively demonstrate that decoupling of MNC formation and decomposition underlie the observed MNC loss under climate warming, which could affect SOC content in temperate forest ecosystems more widespread.