Flannigan said warmer temperatures also spawn an increase in lightning activity. For every degree the temperature rises, there's a 12 per cent increase in lightning. Fires have certainly increased in the last several decades, he said. "The amount of fire activity in Canada, which currently is about 2 1/2 million hectares — about half the size of Nova Scotia — has doubled since the 1970s." The Insurance Bureau of Canada has been watching weather trends with a wary eye.