UCLA Study Warns Record Wildfire Seasons Are "Only The Beginning"

A new study from the University of California – Los Angeles (UCLA) warns that climate change largely driven by human activities is the main issue fueling record wildfire seasons and that they're likely to get worse in coming years. The researchers point to US Geological Survey Data showing an astronomical increase in the amount of land burned yearly by wildfires.

The study was published in the journal Proceedings of the National Academy of Sciences on November 9; it details the use of AI and data gathered over a few decades to explore the link between climate change and the increased risk of wildfires in the Western US. The team found that these states may have passed a "critical threshold" in which climate change caused by human activities is primarily responsible for weather changes that increase wildfire risk.

Key to the findings is a climate metric called vapor pressure deficit (VPD), which is described as "the amount of moisture the air can hold when it is saturated minus the amount of moisture in the air."

The higher the VPD, the researchers explain, the more moisture the air can pull from plants and soil, increasing fire risk. From 1979 to 2020, the study estimates that only 32-percent of the increased VPD levels in the Western US happened naturally, with the remaining 68-percent most likely caused by human-driven climate change.

Using USGS data, the study reports that from 1984 to 2000, 11 states in the Western US averaged 1.69 million acres of land burned by wildfires every year. From 2001 to 2018, that average jumped to 3.35 acres, and 2020 drastically exceeded that with a massive 8.8 million burned acres.

The study's corresponding author Rong Fu explained:

I am afraid that the record fire seasons in recent years are only the beginning of what will come, due to climate change, and our society is not prepared for the rapid increase of weather contributing to wildfires in the American West [...] Our results suggest that the western United States appears to have passed a critical threshold — that human-induced warming is now more responsible for the increase of vapor pressure deficit than natural variations in atmospheric circulation. Our analysis shows this change has occurred since the beginning of the 21st century, much earlier than we anticipated.