This year, during the last week of April, a fire stretched over an apparently much larger area--- total acreage for the burned area has yet to be given, but the fire spread from behind the Spryfield Lions Rink all the way to Fergesons Cove, over 20 kilometres away.
Forest fires in Nova Scotia are rare. Forest fires in Nova Scotia in spring are practically unheard of.
I've pulled up some historic weather data from Environment Canada, for Halifax. From 1977 to 2000, the average daily high temperature for April was 8.4 degrees. On average, only 9.6 days of April see temperatures reach above 10 degrees, and just 0.2 days see temperatures above 20 degrees-- almost statistically irrelevant.
Since 2000, we've seen the following high temperatures:
2001 Average high: 7.2; extreme high: 18.2
2002 Average high: 7.9; extreme high: 14.5
2003 Average high: 8.0; extreme high: 21.8
2004 Average high: 9.1; extreme high: 26.3
2005 Average high: 10.0; extreme high: 20.1
2006 Average high: 10.1; extreme high: 18.4
2007 Average high: 7.9; extreme high: 23.7
2008 Average high: 11.3; extreme high: 18.7
2009 Average high: 10.7; extreme high: 29.5
I stress that we can not attribute any particular weather event, or any particular fire, to climate change. But modelling for global warming suggests that our springs will become significantly warmer, and the trends for the past decade bear that out. We can also expect drier springs, but the data are more erratic in that regard, at least so far-- this year total rainfall for April was slightly more than usual, but it was clustered in just two major rain events, and was followed by an extended dry spell and record warm temperatures.
So, while we can't say positively that either the Porters Lake or the Spryfield fires were the direct result of climate change, we can say with much certainty that the frequency of warmer and drier springs is increasing because of climate change, and with that increasing frequency of warm, dry springs, we should expect more forest fires.
We can also expect, throughout the year, more storms. Like Hurricane Juan, these storms will fall many trees, which will become fuel for future fires.