One Earth最新文献

Ambient air pollutants are leading contributors to global mortality. Despite the well-established risks, most studies have relied on single-pollutant models in limited regions, leaving the combined effects and individual contributions of pollutants unclear, particularly across countries. Here, we integrate daily mortality and air pollutant (nitrogen dioxide [NO₂], ozone [O₃], fine particulate matter, and sulfur dioxide) data from 482 cities in 12 countries/territories from 1998 to 2021 to assess the joint mortality risks and identify the main contributing pollutant through an air quality health index of multi-pollutant constrained groupwise additive models (AQHI-Multi). AQHI-Multi outperformed commonly used air quality indices in capturing the overall mortality risks. O₃ and NO₂ were the leading contributors (accounting for over 70% across countries/territories), with O₃'s share increasing slightly to moderately in most countries/territories. These findings highlight the need for developing air quality indices using advanced multi-pollutant models and the emerging global significance of targeted control of O₃ and NO₂.

Meeting the Paris Agreement's temperature goals requires limiting future carbon emissions, yet current policies make temporarily overshooting the 1.5°C target likely. The potential climate feedback from destabilizing peatlands, storing large amounts of carbon, remains poorly quantified. Using the reduced-complexity Earth System Model OSCAR with an integrated peat carbon module, we found that across various overshoot pathways that temporarily exceed 1.5°C-2.5°C, northern peatlands exhibit net positive feedback, amplifying the overshoot challenge. Warming increases peatlands' net carbon uptake, but this is largely offset by higher methane emissions. We estimated that for each 1°C increase in peak warming, the positive feedback from peatlands decreases the remaining carbon budget by 37 GtCO₂ (22-48 GtCO₂). If the 1.5°C temperature target is exceeded, peatlands would increase carbon removal requirement by about 40 GtCO₂ (16-60 GtCO₂) (8.6%). Our findings highlight the importance of properly accounting for northern peatlands for estimating climate feedbacks, especially under overshoot scenarios.

The years 2023 and 2024 were characterized by unprecedented warming across the globe, underscoring the urgency of climate action. Robust science advice for decision makers on subjects as complex as climate change requires deep cross- and interdisciplinary understanding. However, navigating the ever-expanding and diverse peer-reviewed literature on climate change is enormously challenging for individual researchers. We elicited expert input through an online questionnaire (188 respondents from 45 countries) and prioritized 10 key advances in climate-change research with high policy relevance. The insights span a wide range of areas, from changes in methane and aerosol emissions to the factors shaping citizens' acceptance of climate policies. This synthesis and communications effort forms the basis for a science-policy report distributed to party delegations ahead of the 29th session of the Conference of the Parties (COP29) to inform their positions and arguments on critical issues, including heat-adaptation planning, comprehensive mitigation strategies, and strengthened governance in energy-transition minerals value chains.

The Inflation Reduction Act (IRA), together with other US federal policies, offers a unique window of opportunity to promote health and equity goals through clean energy investments. Seizing these near-term opportunities to realize sizable synergies requires strategic actions from federal, state, and local actors.

In low- and middle-income countries, there is growing evidence that trees in landscapes can support healthy diets. Yet, the bulk of this evidence is based on broad-scale associations and thus fails to tease apart the contributions of different types of trees. Here, we examine how the use of on-farm trees for food, income, and fuel relates to micronutrient adequacy (vitamin A, zinc, iron, and folate) and food sourcing patterns in rural Malawi. We used data from socioeconomic, land use, and dietary surveys conducted with 460 women in both the dry and wet seasons. Our results illustrate that, compared to other uses, the use of on-farm trees for food is the most significant determinant of women's micronutrient adequacy across seasons. While this study does not find consistent dietary benefits from using on-farm trees for only fuel and income, our results suggest that multipurpose on-farm trees can support adequate intake of all measured micronutrients.

Biochar plays a vital role in carbon dioxide removal and achieving carbon neutrality, yet its diverse applications remain underexploited due to techno-economic barriers and limited industry-academia-government cooperation. Enhancing scientific innovation, cross-disciplinary collaboration, and robust policy and regulation support are essential to maximize its positive climate impact.

Carbon dioxide removal (CDR) policy is evolving rapidly but remains fragmented. Upcoming initiatives by the G7 members, which face expectations to be frontrunners in CDR deployment, should follow five principles for robust policies. This will be critical to prepare for distributional conflicts associated with achieving net-zero and net-negative emissions, both domestically and internationally.

Carbon dioxide removal (CDR) is increasingly recognized as essential for achieving the Paris Agreement’s climate goals. Current CDR strategies primarily involve land-based measures, such as afforestation, reforestation, and soil carbon enhancement. These approaches, often labeled as nature-based solutions (NBS) or natural climate solutions (NCS), have sparked debate due to their potential adverse effects on biodiversity and uncertainty around the scale and durability of potential climate benefits. This paper introduces a framework for evaluating trade-offs in land-based CDR activities following the recent United Nations Environment Assembly definition of NBS. This framework emphasizes ecosystem integrity, human rights, and sustainable development, aligning with the objectives of the three Rio Conventions, which provide a guardrail to inform pathways toward feasible and equitable implementation. By applying this framework, we provide a more comprehensive understanding of the environmental and social constraints on CDR, ensuring that climate mitigation efforts do not compromise biodiversity, ecosystem services, or human well-being.

Many modeling studies depend on direct air capture (DAC) in their 1.5°C stabilization scenarios. These studies rely on assumptions that are overly optimistic regarding the cost and scaling-up of DAC systems. This can lead to highly misleading results that can ultimately impact the ability to reach climate stabilization goals.