A new study reports that people are responsible for about 84 percent of all the wildfires in the United States. They are also the reason behind the expansion of the wildfire season.
Over these past few years, wildfires have started becoming increasingly more frequent and bigger. They have also expanded to new areas and can be traced across a longer time period. And according to a new research, this may be because of humans.
Research was carried out by scientists from several universities. They were led by Jennifer Balch from the University of Colorado. Study results were released earlier this week in the PNAS. This is the Proceedings of the National Academy of Sciences of the United States of America journal. The paper was titled as follows: “Human-started wildfires expand the fire niche across the United States”.
For their study, the researchers looked at data from around 1.5 million blazes. These took place from in between 1992 to 2012. All of the analyzed wildfires required the intervention of firefighters.
According to the study results, humans were behind almost 84 percent of all such events encountered across the United States. They were also to blame for around 44 percent of all the acreage burned across this same time period.
Lightning is still the number one cause of the acreage burns. But humans are reportedly expanding the ‘fire niche’. The researchers state that acreage burns have been detected in places that could not have been affected by lighting.
The scientists stated that people are known for consciously or unconsciously causing quite their share of fires. These can start from anything from a campfire to a yard waste fire. But their contribution to the wildfires is higher than initially expected.
And the human ignitions also have quite an impact on the national fire regimes, as stated in the same report.
Natural wildfires mostly occur throughout the summer. They are commonly started by lightning striking hot and dry vegetation. But the manmade fires have extended the wildfire season. Over the past few years, such events also took place in the fall and in spring.
According to the research, most of the human-started, large wildfires especially occurred in the spring. The scientists detected a significant raise of such events across this season. General climate conditions could further increase the risk of wildfires.
The researcher state that global warming is most like to raise this risk across many regions of the American west. It will do so as spring is getting warmer. This is also coming increasingly earlier, according to them. As such, it may also help magnify the detrimental effects of the human-started fires.
According to the study leads, their research may be one if not the most comprehensive assessment of the human role in wildfires. They went to show that the expansion of the fire niche was caused by niche. They did so as they determined that the respective areas have a “historically low lightning strike density”.
Research also determined the top causes behind the man started wildfires. The top five factors include burning debris, arson, equipment use, campfires, and children provoked fires. This last factor was only noted in about 5 percent of the cases. But burning debris was seen to be behind about 29 percent of the cases and arson is the causes of 21 percent of all the wildfires.
As a conclusion, the scientists advise for a modification in the mitigation efforts concerning wildfires. Both local and national policies may benefit from focusing on reducing the expansion of the human-related fire niche.
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