Every year, millions of acres of land are consumed by fire in the United States. By raising temperatures, melting snow sooner, and drying soils and forests, climate change is fueling the problem. Here’s what we know.
Since 2015, the United States has experienced, on average, roughly 100 more large wildfires every year than the year before. This changes region by region, and year to year, but generally we’re seeing more wildfires, more acres burned, and longer, more intense fire seasons.
Fire has historically been a natural part of many wild landscapes. But global warming has changed some of the underlying variables that make wildfires more or less likely to occur every year.
Warmer temperatures increase the likelihood that fires will burn more intensely. They also cause snow to melt sooner, and lead to drier soils, forests, and plants, which act as kindling. Increased droughts, unusual rain patterns, and insect outbreaks that lead to large stands of dead trees are also connected with climate change—and they all make wildfires more likely.
Scientists say the region’s wildfires are the worst in 18 years and have linked their increasing prevalence and intensity to climate change. However, US President Donald Trump has blamed poor forest management for the blazes.
Plumes of smoke from the fires are so large, they have crossed the US and the Atlantic Ocean, carried by the jet stream, and have reached the skies of Europe.
Nasa captured the high-altitude smoke and associated aerosols – particles in the air – as they travelled east to New York City and Washington DC in the middle of last week.
The states of Oregon, Washington and California are experiencing some of the most unhealthy air on the planet, according to global air quality rankings.
In some parts of Oregon, air quality has been so hazardous that it has gone beyond the scale of the state’s Air Quality Index.
Pollution has hit historic levels in five of the state’s cities – Portland, Eugene, Bend, Medford and Klamath Falls, officials said this week.
Pollution from wildfires, contains soot and other fine particles dangerous to human health, as well as noxious chemicals.
Residents who smell smoke or see haze are advised to take precautions against breathing it in and to stay informed about local air quality warnings.
All of the smoke also translates into significant carbon emissions, Nasa says.
It already estimates that 2020 is the highest year of fire carbon emissions for California in its Global Fire Emissions Database, which goes back to 1997.
“Fire emissions this year far outpace the annual totals for all other years, and it is only September 11,” says Douglas Morton, chief of the Nasa Goddard biospheric sciences laboratory.
California’s peak fire season usually runs until October, but can continue until further in the year.