Western Wildfires and Climate Change

Wildfires in the Western U.S. are becoming more frequent and the wildfire season is lengthening, driven by regional temperature increases that are double the global average and earlier spring snowmelt.

• The frequency of large wildfires, defined as those exceeding 1,000 acres, has increased in every Western U.S. state over the last 12 years when compared to the 1980-2000 annual average. Additionally, while local variations exist, wildfire seasons across the region have almost universally lengthened over the last 40 years.
• The Western U.S. is warming at approximately twice the global average rate, with average annual temperatures rising by 1.9° F since 1970. This warming is associated with spring snowmelt occurring 1 to 4 weeks earlier than in the late 1940s, depending on the location.
• Projections indicate that every ecosystem type in the region will experience an increase in average annual burn area, though the impact varies by ecosystem; for example, the Southern Rocky Mountain Steppe-Forest of central Colorado is expected to be more affected than the semi-desert and desert regions of southern Arizona and California.

APA

Union of Concerned Scientists (2013). Western Wildfires and Climate Change. https://www.ucs.org/resources/western-wildfires-and-climate-change

Chicago

Union of Concerned Scientists. Western Wildfires and Climate Change. 2013. https://www.ucs.org/resources/western-wildfires-and-climate-change.

Wikipedia

{{cite report |author=Union of Concerned Scientists |title=Western Wildfires and Climate Change |date=22 July 2013 |url=https://www.ucs.org/resources/western-wildfires-and-climate-change |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{unionofconcernedscientists2013western, author = {{Union of Concerned Scientists}}, title = {{Western Wildfires and Climate Change}}, institution = {Union of Concerned Scientists}, year = {2013}, month = jul, url = {https://www.ucs.org/resources/western-wildfires-and-climate-change}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }