Forest fires have dramatically increased across the western United States in recent decades. These fires have caused widespread forest death, greenhouse gas emissions, and air pollutions.
Although many factors contribute to the recent rise in fire activity, climate warming and drying play a leading role, says a research conducted by University of Idaho and Columbia University.
In the study published in PNAS, researchers demonstrated that human-caused climate change caused over half of the documented increases in fuel aridity (the degree of dryness) since the 1970s and doubled the forest fires since 1984.
Their finding is based on computational models and 30 years’ of weather recordings.
The analysis showed that during 2000–2015, 75% more forested area experienced high fire-season fuel aridity and an average of 9 additional days per year of high fire potential.
In addition, climate change accounted for about 55% of increases in fuel aridity from 1979 to 2015 across western US forests.
Researchers estimated that human-caused climate change contributed to an additional 4.2 million hectares of forest fire area during 1984–2015, nearly doubling the forest fire area expected in its absence.
They suggest that forest fires are going to keep getting bigger due to climate change. Therefore, people should be getting ready for bigger fire years than those familiar to previous generations.
In addition, forest fires might threaten those who live in a forested area with only one road in and one road out.
Eventually, many western forests will burn, and they will become too fragmented for fires to spread easily. At that time, the growth in fire will cease.
Citation: Abatzoglou JT, Williams AP. (2016). The impact of anthropogenic climate change on wildfire across western US forests. PNAS, published online. DOI: 10.1073/pnas.1607171113.
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