Written By: Kaylee Zhou

Wildfires are fires that are uncontrolled and often damage rural environments and ecosystems (National Geographic Society, 2019). Usually, wildfires occur above ground, but recently there have been many wildfires that happen both above and cause damage to the top layer of soil. Wildfires are dangerous because of their ability to quickly spread and decrease air quality. The West Coast of the United States is notorious for their annual wildfires. In particular, the state of California has suffered many long and damaging wildfires in recent years. Scientists from the University of California at Los Angeles and the Lawrence Livermore National Laboratory have collaborated to research how climate change has affected the wildfire patterns over the past twenty years. They concluded that  human-induced climate change has been the main cause of increased wildfires in the United States (ScienceDaily, 2021). 

How was this discovered?

University of California at Los Angeles professor, Rong Fu, led the team’s research study, starting by examining the United States’ Geological Survey data. He compared the increase in area burned for 11 states in the West overtime. From 1984 to 2000, an average of 1.69 million acres burned per year, but from 2001 to 2018, the average acres burned per year increased to 3.35 million. More recently, the National Interagency Coordination Center reported that in 2020, 8.8 million acres burned due to wildfires. 

These statistical points shocked scientists, and they were eager to learn how much of these wildfires were caused by human-induced climate change, rather than natural changes in weather patterns. To continue their research, they turned to Artificial Intelligence. Using this tool, the researchers estimated how much climate change and other factors led to wildfire risk. This estimation was measured through vapor pressure deficit. 

What is vapor pressure deficit?

Vapor pressure deficit is a unit of measurement that tells the difference between the amount of pressure in an air’s water and its saturation point. The saturation point is the maximum amount of pressure the air can carry at its given temperature (Drygair Greenhouse Dehumidifiers, 2021). This unit of measure is important because it provides information about the temperature of the air and how humid an area is. These two factors are both important for learning about wildfires in certain areas. The higher the vapor pressure deficit,  the drier an area is, leading to increased chances for wildfires. Professor Park Williams from Columbia University pointed out that the vapor pressure deficit for California reached its all-time high in August 2020. This information showcases the correlation between vapor pressure deficit data and wildfires, since that time period also led to large, uncontrollable wildfires across California (Meyer, 2020). 

At the conclusion of his study, Fu’s research results indicated that from 1979 to 2020,  68% of the vapor pressure deficit increase in the United States resulted from human-induced global warming. 

Conclusion

Rong Fu believes that this research was beneficial for allowing scientists to understand that wildfires will progressively become more intense and more frequent in the future. In fact, he said, “Our results suggest that the western United States appears to have passed a critical threshold — human-induced warming is now more responsible for the increase of vapor pressure deficit than natural variations in atmospheric circulation” (ScienceDaily, 2021). Overall, Fu tried to express that humans have caused much damage over the decades, but he never expected this damage to impact society so much, so quickly. The researchers initially thought that these consequences would only occur decades and centuries later, but instead they occurred much earlier than expected. On a lighter note, the recognition of these environmental issues is the first step towards solving the problem.  

References and Sources

Meyer, R. (2020, September 16). The most important number for the West’s hideous fire season. The Atlantic. Retrieved November 29, 2021, from https://www.theatlantic.com/science/archive/2020/09/most-important-number-for-the-wests-wildfires-california/616359/. 

National Geographic Society. (2019, July 15). Wildfires. National Geographic Society. Retrieved November 29, 2021, from https://www.nationalgeographic.org/encyclopedia/wildfires/. 

ScienceDaily. (2021, November 5). Increasingly frequent wildfires linked to human-caused climate change. ScienceDaily. Retrieved November 29, 2021, from https://www.sciencedaily.com/releases/2021/11/211105114305.htm. 

VPD – what is vapor pressure deficit? Drygair Greenhouse Dehumidifiers. (2021, August 16). Retrieved November 29, 2021, from https://drygair.com/vpd-vapor-pressure-deficit/.