Scientists frequently condemn journalists for being too quick to assert that particular events either support or call into question anthropogenic climate change. Indeed, reporting responsibly on the issue can be challenging. One the one hand, one cannot ignore the long-term contribution climate change makes to the frequency and severity of events; on the other, one doesn’t want to propagate the false idea that the accuracy or inaccuracy of climatic science hinges on a small number of extreme events of local weather trends.
A recent RealClimate post considers the case of Australia’s terrible recent brushfires. It considers a century worth of evidence on Australian brushfires, examining the importance of maximum temperatures, relative humidity, wind speed, and drought factors. Climate change trends are pushing in the direction of higher average temperatures and reduced rainfall. In the end, it comes to a measured by sobering conclusion:
While it is difficult to separate the influences of climate variability, climate change, and changes in fire management strategies on the observed increases in fire activity, it is clear that climate change is increasing the likelihood of environmental conditions associated with extreme fire danger in south-east Australia and a number of other parts of the world.
That may not be the kind of conclusion that translates easily into a headline for a popular newspaper, but it is the sort that we need to consider when making public policy on both climate change mitigation and adaptation.
The fourth report of the Intergovernmental Panel on Climate Change (IPCC) concluded back in 2007 that:
An increase in fire danger in Australia is likely to be associated with a reduced interval between fires, increased fire intensity, a decrease in fire extinguishments and faster fire spread. In south-east Australia, the frequency of very high and extreme fire danger days is likely to rise 4-25% by 2020 and 15-70% by 2050.
Those fires will naturally contribute to positive feedbacks within the climate system, as heat-induced dryness prompts the fire-induced emission of greenhouse gasses previously bound up in forests and grasslands.