Climate change is not the only reason for wildfires and extreme weather events; lightning-caused fires and human actions also factor as a cause.
A study published by the Proceedings of the National Academy of Sciences in 2017 showed that people ignited 84% of the blazes in 1992 and 2012; sparks from railroads and power lines also routinely cause wildfires. The researchers have found that human-ignited fires occurred in the spring, fall, and winter when forests tend to be moist, and lightning-ignited fires were clustered in the summer.
Several factors have likely enabled increased forest fire activity in the United States in recent decades, including the legacy of fire suppression and human settlement, natural climate variability, and human-caused climate change. The U.S. has witnessed increases in prolonged periods of excessively high temperatures, heavy downpours, and in some regions, severe floods and droughts. Climate change has been a critical factor in increasing the risk and extent of wildfires but temperature, soil moisture, and the presence of trees, shrubs, and other potential fuel also directly or indirectly have ties to forest fires. Many factors cause extreme weather events. Heavy Downpours have increased over the last three to five decades in the Northeast, Midwest, and upper Great Plains. Human-caused warming is one of the factors for heavy downpours. Moreover, Floods are caused or amplified by both weather, and human-related factors include structural failures of dams and levees, altered drainage, land-cover alterations, heavy or prolonged precipitation, snowmelt, thunderstorms, and storm surges from hurricanes.
Therefore we can say that several factors directly or indirectly contributed to the wildfires and extreme weather events. Climate change is interdependent on human activities, and it is one of the factors for environmental change.
Correction: The previous version of this fact-check had been checked differently. However, the claim has now been fact-checked for 'Climate change is the only cause of wildfires and extreme weather events in the United States.' Additional information on the claim was revealed by the National Academy of Sciences and the Congressional Research Service, saying that climate change is not the only reason for Wildfires and extreme weather events.