Climate change is the reason for the intense fires across the western American states over the past. Some of these factors are people, forest management decisions that allowed a vast amount of vegetation that can burn quickly and turn into fuel. Fire is simple in only requiring three components which are the right weather and climate conditions, plenty of combustible fuel, and a spark. According to Jennifer Balch, a fire ecologist at the University of Colorado, Boulder, "people are changing all three of those."
A study which Balch was a co-author, found that humans were responsible for 97 percent of the ignitions that caused fires that then threatened homes in the wildland-urban interface between 1992 and 2015. The clearest connection with climate change is the warming air temperatures. the planet has heated up continuously since the start of the Industrial Revolution in the late 1800s. With humans beginning to burn massive amounts of fossil fuels, releasing carbon dioxide that traps excess heat in the atmosphere. This has caused the average temperatures to raise up 1.8 degrees and California is closer to 3 degrees. Since the 1980's the warming has accelerated per decade, and it is most likely to accelerate further in the future.
Even though that seems like a small amount, but it can have a major effect. Hot air, if not 100 percent humidity, is like a thirsty sponge: it soaks up water from whatever it touches (plants both living and dead, soil, lakes, and rivers. The hotter and drier the air, the more it sucks up, and the amount of water it can hold increases exponentially as the temperature rises. The small increases in the air's heat can mean big increases in the intensity with which it pulls out water. Scientists can measure this "vapor pressure deficit" which the difference between how much water the air holds and how much it could hold. If this deficit is cranked up for a long time, soils and vegetation will parch. Brief heat spells will dry out the smallish stuff or already dead fuel. This causes record-breaking heat waves in the western United States during August and early September and forms more combustible material, and associated drought and the regional vapor pressure deficit climb to record levels.
With the snow melting earlier, snow cover in February and March was below its usual average. The heat kicked in and remained, the average temperature across the U.S. was 2.6 degrees Fahrenheit above the 20th-century average. California along with much of the West had longer and deeper aridity. This also non coincidentally resulted in five of the state's hottest years on record occurred in the past decade. This climate change affects the snow that usually provides about 30 percent of the state's summer water needs, is melting earlier in the year. Giving the plants and soil longer to dry out and become potential fuel.
Higher autumn temperatures and less precipitation, in particular, a growing delay in the onset of winter rains which usually puts an end to the fire season in California, which have led to a 20 percent increase in the number of autumn days for burning. The western fire season has extended by at least 84 days since the 1970s. California's fire protection service has stated publicly that it no longer considers a wildfire "season," due to the season being year-round. The fires are also changing growing larger and more intense, this can increase future fire risk. This also affects forests as they burn and we cant count on them to self-regenerate. These similar plant transitions are also occurring across other fire-prone habitats, like Southern California's chaparral and Colorado's forests.
Climate change has increased fire risk in both direct and indirect ways. Even if it's a natural spark that starts a forest fire. Climate change, forest management, human behavior, and learning to adapt to the new reality and mitigate risks which require swift and decisive action from many different angles. Balch states "That's the tricky thing about fires-it isn't any one thing that's causing them, it's multiple puzzle pieces fitting together."
source:
https://www.nationalgeographic.com/science/2020/09/climate-change-increases-risk-fires-western-us/
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