Scientists in California have confirmed that fires in the western US are linked to climate change confirmed the link between climate change and the increase in the area of land affected by major forest fires. This is reported in an article published in the journal Proceedings of the National Academy of Sciences.
Over 17 years, from 1984 to 2000, the average area burned in 11 western US states was 683 thousand hectares per year. Over the next 17 years, until 2018, the average area burned up was approximately 1.35 million hectares per year. And in 2020, according to a report from the National Interagency Coordination Center, the amount of land devastated by wildfires in the West reached 3.5 million hectares.
To determine the cause, scientists used artificial intelligence, which analyzed data on climate and fires. This made it possible to identify the role of the key factor contributing to the ignition – the lack of steam pressure. This parameter shows the difference between the theoretical vapor pressure in saturated air (humidity at the level of one hundred percent) and the actual pressure of water vapor held in the air at the same temperature. When vapor pressure deficits are high, air absorbs more moisture from soil and plants.
The study found that 68 percent of the total increase in vapor pressure deficits in the western United States between 1979 and 2020 was probably due to global warming caused by human activity. The remaining 32 percent are due to natural causes. Thus, climate change caused by human activities is the main reason for the increase in the number of fires in the western United States.