Climate Change and Forest Fires in the Western United States

Large forest fires have occurred more frequently in the western United States since the mid-1980s, as spring temperatures increased, mountain snow melted earlier, and summers became hotter, according to new research. Almost seven times more forested federal land burned during the 1987–2003 period than during the prior 17 years. In addition, large fires occurred about four times more often during the latter period. The study represents the most systematic analysis to date of recent changes in forest fire activity in the region. The increases in both fire extent and frequency are strongly linked to higher March-through-August temperatures and are most noticeable in mid-elevation forests of the northern Rocky Mountains. The findings suggest that climate change, rather than fire suppression policies or fuel accumulation, is the primary driver of the recent rise in large forest fires.