Wildfires

Wildfire blowups, fire whirls, towering thunderstorms: When fires get large and hot enough, they can actually create their own weather. In these extreme fire situations, firefighters’ ordinary methods to directly control the fire don’t work, and wildfires burn out of control. Firefighters have seen many of these risks in the enormous Park Fire burning near Chico, California, and other wildfires in summer 2024. But how can a fire create weather? Satellite images show how the Park Fire near Chico, Calif., created intense pyrocumulonimbus plumes, visible in white, in July 2024. CSU/CIRA and NOAA I’m an atmospheric scientist who uses data collected by satellites in weather prediction models to better anticipate extreme fire weather phenomena. Satellite data shows fire-produced thunderstorms are much more common than anyone realized just a few years ago. Here’s what’s happ...

Extreme heat has already made 2024 a busy wildfire year. More acres had burned by mid-July than in all of 2023, and several communities had lost homes to wildfires. As fire season intensifies across the West, there are steps homeowners can take to make their homes less vulnerable to burning and increase the likelihood that firefighters can protect their property in the event of a wildfire. We research wildfire risk to homes and communities. Here’s what decades of research suggest homeowners in high-fire-risk areas can do to protect their properties. This house near Cle Elum, Wash., survived a 2012 wildfire because of the defensible space around the structure, including a lack of trees and brush close to the house, according to state officials. AP Photo/Elaine Thompson Small improvements make big differences A structure’s flammability depends on both the materials that were used to build...

When wildfire smoke is in the air, doctors urge people to stay indoors to avoid breathing in harmful particles and gases. But what happens to trees and other plants that can’t escape from the smoke? They respond a bit like us, it turns out: Some trees essentially shut their windows and doors and hold their breath. As atmospheric and chemical scientists, we study the air quality and ecological effects of wildfire smoke and other pollutants. In a study that started quite by accident when smoke overwhelmed our research site in Colorado, we were able to watch in real time how the leaves of living pine trees responded. How plants breathe Plants have pores on the surface of their leaves called stomata. These pores are much like our mouths, except that while we inhale oxygen and exhale carbon dioxide, plants inhale carbon dioxide and exhale oxygen. A highly magnified view of stomata in a maize leaf. Umberto Salvagnin/Fli...

When wildfires rage, the immediate threat is obvious – but smoke from the fires actually kills far more people than the flames. As fires become more frequent, that smoke is leading to a public health crisis. In a new study published in the journal Science Advances, we found that wildfire smoke likely contributed to more than 52,000 premature deaths across California alone from 2008 to 2018, with an economic impact from the deaths of more than US$430 billion. Previous studies have examined the short-term health risks from wildfire smoke, but few have assessed how exposure to wildfire smoke over years adds up to shorten human lives. Smoke from far-off wildfires turns the skies orange over San Francisco in 2020. Running in wildfire smoke carries harmful particles deep into a person’s lungs. AP Photo/Tony Avelar Wildfire risk and severity have grown as the climate has changed and as more...

A tiny, vibrant world thrives along the rocky bottom of most streams. As sunlight filters through the water, mayfly nymphs, no larger than your fingernail, cling to algae-coated cobbles. Their brushlike mouthparts scrape the greenish coating, leaving faint trails as they feed. Six spindly legs anchor them against the current, while feathery gills wave gently, drawing oxygen from the flowing water. This scene is common in well-maintained creeks and streams that flow through populated areas. But when wildfires sweep through, the toxic materials left behind can devastate this ecosystem. When you think of urban wildfires, you might picture charred trees and houses. But beneath the surface of nearby streams, fires can also cause a silent upheaval – one that affects populations of creatures that are important indicators of the water’s health. Images of some of the benthic invertebrates that help keep streams healthy, and whose disa...