One Earth最新文献

Remote sensing plays a central role in monitoring wildfires throughout their life cycle, including assessing pre-fire fuel conditions, characterizing active fire locations and emissions, and evaluating post-fire effects on vegetation, air quality, and climate. This primer examines current remote sensing products used in wildfire research, focusing on their application in deriving burned area and emissions data and tracking the dynamic spread of individual fire events. We evaluate the strengths and weaknesses of these products and address key challenges such as generating complete, continuous, and consistent long-term monitoring data. We also explore future opportunities and directions in remote sensing technology for wildfire characterization and management.

Anthropogenic climate change is driving extreme fire seasons, challenging the effectiveness of fire management practices developed over the last 50 years. New and diverse strategies are needed to achieve safe coexistence in an age of megafires. A redefinition of the wildfire management paradigm is central to the shift, placing greater emphasis on the adoption of high-tech solutions for early fire detection and rapid ignition suppression.

Climate change is profoundly changing fire-vegetation interactions and the carbon cycle across fire-adapted ecosystems. Increasingly frequent extreme fire events in combination with human activity put ever more pressure on these systems. Limited process-based understanding and data hampers effective management strategies for these fire-adapted systems under ongoing global change.

Dr. Wayne Cascio, M.D., serves as the director of the Center for Public Health and Environmental Assessment at the US Environmental Protection Agency (EPA). Prior to his current position, Dr. Cascio worked as a physician and scientist focusing on the impacts of air pollutants on heart health. At the EPA, he has spearheaded efforts to help reduce the public health risks of wildfire smoke. The views of Dr. Cascio are his only and do not necessarily reflect those of the EPA.

New particle formation (NPF) in fire smoke is thought to be unlikely due to large condensation and coagulation sinks that scavenge molecular clusters. We analyze aircraft measurements over the Amazon and find that fires significantly enhance NPF and ultrafine particle (UFP < 50 nm diameter) numbers compared to background conditions, contrary to previous understanding. We identify that the nucleation of dimethylamine with sulfuric acid, which is aided by the formation of extremely low volatility organics in biomass-burning smoke, can overcome the large condensation and coagulation sinks and explain aircraft observations. We show that freshly formed clusters rapidly grow to UFP sizes through biomass-burning secondary organic aerosol formation, leading to a 10-fold increase in UFP number concentrations. We find a contrasting effect of UFPs on deep convective clouds compared to the larger particles from primary emissions for the case investigated here. UFPs intensify the deep convective clouds and precipitation due to increased condensational heating, while larger particles delay and reduce precipitation.

The western United States is home to most of the nation’s oil and gas production and, increasingly, wildfires. We examined historical threats of wildfires for oil and gas wells, the extent to which wildfires are projected to threaten wells as climate change progresses, and exposure of human populations to these wells. From 1984 to 2019, we found that, cumulatively, 102,882 wells were located in wildfire burn areas, and 348,853 people were exposed (resided within ≤ 1 km). During this period, we observed a 5-fold increase in the number of wells in wildfire burn areas and a doubling of the population within 1 km of these wells. These trends are projected to increase by late century, likely threatening human health. Approximately 2.9 million people reside within 1 km of wells in areas with high wildfire risk, and Black, Hispanic, and Native American people have disproportionately high exposure to wildfire-threatened wells.

Lake desiccation is a global problem associated with increased human water use and climate change. Like other drying lakes, Utah’s Great Salt Lake (GSL) is producing health-harming dust. We estimate social disparities in dust fine particulate matter (PM_2.5) exposures based on four policy-relevant water-level scenarios. Dust PM_2.5 exposures would increase as GSL levels drop (e.g., from 24.0 μg m⁻³ to 32.0 μg m⁻³). People of color and those with no high school diploma would experience disproportionately higher exposures (e.g., 28.4 μg m⁻³ for Pacific Islanders vs. 26.0 μg m⁻³ for Whites under very low lake levels). Racial/ethnic disparities would be reduced if GSL water levels rose. If the GSL vanished, racial/ethnic disparities between the highest and lowest exposed groups would be moderate (16.3%). If the GSL stabilized at healthy levels, those disparities would be smaller (7.9%). While all nearby residents face unhealthy dust exposures, findings reveal exposure disparities for socially disadvantaged groups.

Twenty-first century wildfires pose multifaceted challenges exacerbated by climate change and urbanization. Current mitigation measures often fall short, necessitating inclusive approaches that integrate Indigenous knowledge, historical ecology, and community-based strategies. Collaborative and integrated efforts are crucial to fostering sustainable fire management practices for resilient ecosystems and communities.

Forest fires are intensifying in a world bearing rapid anthropogenic climate change. Among the many factors affecting forest fire frequency and severity, such as hotter and drier conditions, there is also the increase in a certain kind of insect: bark beetles. Most bark beetles prefer dead tree wood as their diet, but some (e.g., the mountain pine beetle) have evolved to mass attack living trees. Previously, their larvae were kept in check by early winter freezes. However, in warmer winters, thanks to climate change, the larvae no longer freeze, plus more trees are drought and heat stressed, resulting in soaring reproduction of these beetles. The increasing volume of dry and combustible woody materials can help feed larger fires. Suze Woolf, an artist preoccupied with climate impacts on forests, observed their hieroglyphic “scribing” on bark and sapwood while hiking and turned those observations into a series of Bark Beetle Books. “Volume XIV: Ars datum est” is one that presents the trails of bark beetles—i.e., galleries where beetles deposit eggs—as a bar in a bar chart. The chart represents forest areas affected in British Columbia and Alberta from 1999 to 2007. These trails, to Suze, are undecipherable cryptograms that seem like a message we’re just not getting. This artist book, as Suze’s meditation on human impact, illustrates how bark beetles enthusiastically respond to the conditions we cooked: a warming world, a century of fire suppression, and a vast menu of even-aged agri-timbers over which we and the beetles now compete.

Around the world, fire regimes are shifting due to changing climate, land use and management, and human populations and infrastructure. While fire is a healthy and necessary process for many ecosystems, altered fire regimes are increasing risk to both people and wildlife in many regions. Reducing risk requires a holistic approach with investment from many stakeholders. In this Voices, we ask: what aspects of fire hazard, vulnerability, and exposure can be mitigated, and what collaborations does this require?