Neville Nicholls, a Lead Author for the IPCC's Fourth Assessment report has attempted to find deficiencies in a recent paper dealing with climate influences on bushfires in Australia between 1925 and 2010. (Crompton, R. P., K. J. McAneney, K. Chen, R. A. Pielke Jr., and K. Haynes, 2010. Influence of Location, Population and Climate on Building Damage and Fatalities due to Australian Bushfire: 1925-2009. Weather, Climate, and Society, Vol. 2, pp. 300-310, doi:10.1175/2010WCAS1063.1.) This paper found that: "There is no discernable evidence that the normalized data are being influenced by climate change due to the emission of greenhouse gases."
Nicholls' attempt at discrediting the study has been slapped down convincingly by the study authors. Nicholls' comment is HERE. And the response HERE. The original authors conclude the exchange thus:
Our result—that there is no discernable evidence that normalized building damage is being influenced by climate change due to the emission of greenhouse gases— is not surprising, when you consider that bushfire damage is not solely a function of bushfire weather; far from it, in fact. Even given a gradual aggravation of bushfire weather due to anthropogenic climate change or other factors, a bushfire still has to be ignited. Once ignited, a bushfire then has to traverse the landscape and impact a populated area, where outcomes in terms of damage will be a function of the spatial disposition of dwellings with respect to the fire front, and especially distance of properties from the bushland boundary (McAneney et al. 2009). These factors all contribute a large degree of stochasticity to eventual event loss outcomes.
The Nicholls (2011) speculations are worthy of discussion but no evidence is presented to support these contentions. Moreover, the evidence that we are aware of and have presented here in relation to a potential bias in our normalization methodology and to the possible sources of reduced vulnerability does not undermine our findings in any way.
What's newsworthy here is not just that the evidence further supports the original conclusions (that there is no discernable evidence that normalized building damage is being influenced by climate change due to the emission of greenhouse gases), but that an IPCC lead author can put together such a poor case, backed without any evidence! Is this the sort of people the government is relying on to provide scientific advice-those that rely on idle speculation, rather than back their claims with evidence?
ABC did not report on the original study so we don't expect a follow up. This is very surprising given the lead authors are based in Australia and its a highly relevant work with broad policy implications. ABC instead promote a report by the government's climate commission that includes this misleading statement regarding bushfires: 'The intensity and seasonality of large bushfires in southeast Australia appears to be changing, with climate change a possible contributing factor" Page 40. Once again ABC severely misinform its audience.