One Earth最新文献

The growing demand for woody biomass to meet the environmental and climate objectives of the European Green Deal raises concerns about the capacity of forest ecosystems to sustain their diverse services and functions. Deadwood, an often-overlooked source of biomass, exemplifies this dilemma, yet the evidence needed to enhance its management is sparse. Here, we put the role of deadwood into perspective through a literature review and comparison of estimates in managed and unmanaged forests. We demonstrate that deadwood intersects many overlapping and sometimes conflicting policies, playing a multifaceted role in the bioeconomy, biodiversity conservation, soil health, fire mitigation, bioenergy, and carbon storage. Given the increasing pressure on deadwood and the ecosystem services it provides, we argue that coherent and mutually supportive policies are needed to develop multifunctional pathways that reconcile deadwood management with biodiversity, bioenergy, and climate objectives. Therefore, we suggest that harmonized data and monitoring are essential, along with transdisciplinary collaboration, to identify trade-offs between biomass uses and values and ensure the maintenance of functional forest ecosystems.

Low knowledge sharing across disciplines studying geo-evolutionary processes determining species adaptations hinders the mitigation of biodiversity loss driven by human-induced climate warming. Further, the impacts of microbes and light regimes on species adaptations to accelerated climate warming are largely ignored. On a geologic timescale, range shifts to higher latitudes necessitate adaptation to new light environments, including extreme polar seasons, i.e., "polar night." Chemical crosstalk among coevolving microbes and plants modulates ecologically relevant traits, and photosensitive and other microbes may aid plant adaptation. We hypothesize that hybridization in new "circumpolar hybrid zones” and plant-microbial cooperation in those zones and elsewhere will be significant in maintaining genetic admixture and species diversity on a geological timescale. We propose the concept of circumpolar hybrid zones and an integrated framework, inclusive of microbes, to unite disparate research disciplines, advance understanding of evolution, and improve strategies for climate adaptation and mitigation.

Climate change has intensified extreme temperature events, posing significant challenges to public health and equity. While the impact of extreme temperatures on mortality is known, racial disparities in this context are less explored. Most studies on the United States focus on specific regions or do not address the effects of cold. We provide a comprehensive assessment across the country using a new database of linked administrative and census data with precise meteorological information. Analyzing death records from over 3,000 counties (1993–2005), we find that both cold and hot days increase mortality rates, with hot days disproportionately impacting racial minorities. Our analysis suggests that recent temperature increases could exacerbate racial disparities in temperature-related deaths, highlighting the need to investigate how climate change affects different population subgroups and exacerbates social inequities.

Nine years after the Paris Agreement was adopted, it is clear that negative-emission technologies are required to keep 1.5°C, or even 2°C, of global warming in reach. Yet carbon dioxide removal (CDR) strategies remain rife with political, technical, economic, environmental, and geographic challenges. This Voices surveys the pitfalls of incorporating carbon-negative technologies into climate mitigation plans and asks: how can we navigate around the challenges to make CDR a reliable component of climate mitigation?

Carbon dioxide removal (CDR) technologies are essential to address climate change and serve to compensate for legacy and hard-to-abate greenhouse gas emissions. Although near-term emissions reductions should be the priority, development and deployment of CDR must proceed now to ensure that relevant technologies are ready at scale in the future. Despite a rapid growth in CDR purchases, no single standardized methodology for evaluating project-level net CO₂ removal exists. Life cycle assessment (LCA) frequently produces net-negative emissions footprints, but only a small subset of those systems achieves a net flux of CO₂ out of the atmosphere. In contrast to LCA, CDR accounting uses expansive system boundaries and excludes avoidance credits to distinguish between systems that achieve net removal from those that only contribute to emissions mitigation. This primer discusses a framework and set of metrics for CDR accounting.

Expectations for agricultural landscapes in subtropical and tropical regions are high, aiming for conservation and development amid climate change, unfair trade, poverty, and environmental degradation. Landscape approaches (LAs) are gaining momentum as means to reconcile expectations, although they face multiple challenges, including unclear distinctions among LAs and stakeholder involvement. We studied 380 LAs from three continents via questionnaires with landscape managers (2012–2015 and 2021) and identified three LA types through cluster analysis: an “integrated” type with longer-term, multisectoral goals involving various stakeholders early in the design and two shorter-term types focused on sectoral priorities of preservation or production. Better-performing LAs are associated with longevity, inclusivity, and diversified investments across goals, notably those enabling social justice. International stakeholder analysis shows broad support for LAs but identifies gaps between support and LAs’ needs. The growing interest in LAs is promising. Yet, underpinning effective and lasting LAs that reconcile multiple expectations requires better support.

There is an increasing urgency to implement large-scale ecosystem restoration to mitigate the biodiversity and climate crises. These efforts must be scaled up to counteract the widespread degradation of the world’s forests, although restoration costs can often limit their application. Thus, there is a pressing need to identify cost-effective approaches that catalyze landscape-scale ecological recovery. Here, we highlight seven assisted restoration innovations with demonstrated local-scale results that, once upscaled, hold promise to rapidly regenerate forests. We comprehensively assessed how each approach facilitated forest, woodland, and/or mangrove recovery across 143 studies. Our results reveal techniques with a marked ability to catalyze vegetation recovery compared to “business-as-usual” approaches. However, the context-dependent cost-benefit ratio and feasibility of applying particular approaches requires careful consideration. Our assessment emphasizes that we already have many of the tools necessary to drive the terrestrial restoration movement forward. It is time to implement and assess their efficacy at scale.

Glaciers are crucial water resources in the Third Pole (the Tibetan Plateau and its surroundings) and are shrinking in response to climate change. Glacier albedo is an expression of glacier interactions with climate and dust/black carbon, and albedo reduction enhances glacier mass loss, but its changes and potential drivers remain poorly quantified. We leverage satellite observations to explore the variability of glacier albedo and understand its sensitivity to potential drivers and its future evolution. We find that glacier albedo has declined during 2001–2020, but high interannual variability is also an important signal. These variations are highly sensitive to air temperature and snow conditions and to nearby dust/black carbon emission sources. Future changes to these drivers will lead to further decreases of 2.9%–12.5% in glacier albedo by 2100 under different warming scenarios. These findings highlight the importance of albedo in glacier future evolution and the urgency of action to mitigate climate warming.

Defining an Anthropocene epoch from the mid-1900s allows representing human environmental impacts’ triphasic nature within the International Geological Timescale. Such an epoch captures humanity’s current planetary importance, with the Holocene and Late Pleistocene representing earlier phases of intensifying impacts. This formal framework empowers science and action toward planetary stewardship.

Nitrogen oxides (NO_x) and ammonia (NH₃) contribute substantially to current global fine particulate matter (PM_2.5) pollution. Their future role remains unclear and is complicated by interactions with background emissions. Here, we show that under climate mitigation scenarios, by 2050, a hypothetical phaseout of anthropogenic NH₃ emissions would reduce PM_2.5 by 20%–60% locally and be more effective than phasing out NO_x. Reducing NH₃ by 25%, instead, would be less effective than 25% NO_x reduction for many regions. Future reductions of NO_x and sulfuric dioxides from clean energy transitions would shift the nonlinear chemical regime of secondary inorganic aerosol formation toward NH₃ saturation. The later NH₃ controls are installed, the deeper the required reductions will be to be effective, although for many regions such levels are still within technical feasibility, while NO_x controls will always remain effective. Nitrogen reductions remain useful for achieving the World Health Organization guideline target for PM_2.5, and NH₃ controls need to happen sooner rather than later.