Journal Article

Cloud-to-ground (CG) lightning is a major source of summer wildfire ignition in the western United States (WUS). However, future projections of lightning are uncertain since lightning is not directly simulated by most global climate models. To address this issue, we use convolutional neural network (CNN)-based parameterizations of daily June-September CG lightning.

Despite widespread concern over increases in wildfire severity, the mechanisms underlying this trend remain unclear, hampering our ability to mitigate the severity of future fires.

Area burned by wildfire has increased in western US forests and elsewhere over recent decades coincident with warmer and drier fire seasons. However, high–severity fire—fire that kills all or most trees—is arguably a more important metric of fire activity given its destabilizing influence on forest ecosystems and direct and indirect impacts to human communities.

The sagebrush biome in the western United States is a focus of widespread conservation concern due to multiple interacting threats including larger, more severe wildfires. Given the immense scale of the region and limited resources, prioritizing restoration treatments is essential for optimizing risk reduction and managing for resilient ecosystems.

Managers across the western US seek effective fuel treatment strategies to mitigate hazardous fuel loads and risks of high severity fire in dry conifer forests. Conventional fuel hazard reduction treatments emphasis reducing canopy fuel continuity and surface fuel loading using an even spaced, thin-from-below approach, with pile or broadcast burning of residual surface fuels.

Pathways to achieving net-zero and net-negative greenhouse-gas (GHG) emission targets rely on land-based contributions to carbon (C) sequestration. However, projections of future contributions neglect to consider ecosystems, climate change, legacy impacts of continental-scale fire exclusion, forest accretion and densification, and a century or more of management.

Increasing wildfires are causing global concerns about ecosystem functioning and services. Although some wildfires are caused by natural ignitions, it is also important to understand how human ignitions and human-related factors can contribute to wildfires.

Drought, wildfire, wind, insects, and pathogens can interact across space and time to shape forest ecosystems. Although subdisciplines in ecology have long studied individual disturbances, their interactions remain poorly understood, particularly under climate change. Further, inconsistent terminology used to describe these interactions compounds this gap.

Although half of Earth’s population resides in the wildland-urban interface, human exposure to wildland fires remains unquantified. We show that the population directly exposed to wildland fires increased 40% globally from 2002 to 2021 despite a 26% decline in burned area.

Wildfire activity has accelerated with climate change, sparking concerns about uncharacteristic impacts on mature and old-growth forests containing large trees.