U.S. West should expect bigger wildfires more often: report

A warming trend has contributed to a sharp rise in the number and size of wildfires on forest lands in the U.S. West, where big burns are likely to become the norm, according to a report released on Tuesday by a climate research group. The average annual number of fires that cover more than 1,000 acres has nearly quadrupled in Arizona and Idaho and doubled in California, Colorado and six other Western states since 1970, the study by Climate Central showed. The report, which analyzed 42 years of records about fires on U.S. Forest Service lands in 11 Western states, linked rising spring and summer temperatures in the region to a fire season that begins earlier, ends later and sparks larger, more frequent blazes.