A team led by Philip Dennison of the University of Utah in Salt Lake City used satellite data to measure areas burned by large fires since 1984. The researchers also looked at climate variables such as seasonal temperature and rainfall.
The results indicated that in the region stretching from Nebraska to California, the number of wildfires more than 400 hectares in size increased by seven fires a year between 1984 and 2011. The total area burned by these fires increased at a rate of about 36,000 hectares a year.
The researchers also found that most areas that saw increases in fire activity also experienced increases in drought severity. ‘We looked at the probability that increases of this magnitude could be random, and in each case, it was less than one per cent,’ said Dennison.
‘Twenty eight years is a pretty short period of record, and yet we are seeing statistically significant trends in different wildfire variables – it is striking,’ said one of the study’s co-authors, Max Moritz of the University of California-Berkeley Cooperative Extension.
Although the study stopped short of linking the changes to anthropogenic climate change, the authors did point out that they are in line with projections from models linking fire patterns and climate.
This story was published in the June 2014 edition of Geographical Magazine