Natural disasters and ‘climate change’

I’ve written about this subject before, and mentioned approvingly both Roger Pielke Jnr of the USA and John McAneney of Australia, who seem to have written about it most sensibly, by relating the costs of disasters over time to relative GDP at each time. Well, Roger Pielke was asked to write about it on a new website in the USA (http://fivethirtyeight.com), and copped some incredible flak from the orthodox, which prompted McAneney to write something in response, which I am most happy to publish  here. What follows is John McAneney’s text, slightly re-arranged by me.

There is a widespread view that the cost of natural disasters is rising because of global climate change. That perception is wrong. The reality is much more prosaic: costs are rising due to more stuff sitting in harm’s way. To the degree that climate change is implicated at all, its contribution is currently unmeasurable.

This statement should not be controversial: in fact, it is now IPCC orthodoxy. Nonetheless for articulating this orthodoxy on Nate Silver’s new website, 538, Roger Pielke Jr., a Professor at Colorado University, found himself at the centre of a maelstrom of invective. The witch hunt on the blogosphere was disturbing.

Even more unseemly was that several well known scientists of the climate change church felt compelled to join in the concert of the trolls and deny what is well-supported peer-reviewed science, in fact some 30-odd studies on different perils and in different countries. In the eyes of these self-appointed High Priests, Pielke Jr’s crime has been to hold them, rather than those malevolent trouble makers, the climate change deniers, to task, demanding that their rhetoric meet some benchmark of truthfulness, an act of unforgivable ‘treachery’ in their eyes that in the 15^th century would have invited a heresy charge before the Inquisition.

In an act of palliative care, Prof. Kerry Emanuel of MIT was invited to provide an antidote to Pielke Jr’s article on 538. In it Emanuel alludes to a 2011 paper that I co-authored with Pielke Jr and Ryan Crompton. It asks how long it might be until we might be able to detect a statistically significant signal in the economic losses from land falling hurricanes in the US. Based on recent climate modelling, we found that this could take centuries and depending upon what climate model was used to set the basin-wide boundary conditions under a warmer climate, the time frame, called the emergence time scale, varied between 120 years and 550 years.

Just to be clear this time scale does not mean that a warming climate poses no threats before then; rather it is just pointing out the reality that it takes an awfully longtime to detect a small (climate change) signal in a very noisy one (loss data). The corollary is that it is silly to use each new natural disaster – a typhoon in the Philippines, a man-made flood in Australia, a landslide in Brazil, a wildfire somewhere else — as the latest expression of climate change. But unfortunately, for the climate change alarmists, any departure from the average is seen as prima facie evidence that the horsemen of the Apocalypse are ‘a comin’. The entrails of a goat might prove more convincing. And like we never had bad weather before!

Now like most scientists, I am not an expert on climate science. In fact the complexity of the ocean-climate-land system means that nobody can truthfully accept this mantle, although some seem only too happy to do so. However a career spent trying to understand complicated systems, has led to a healthy skepticism of models. And personally the unmodelled slowdown in the rate of temperature rise over the last 15-odd years provides me with little confidence that the current crop of global climate models can accurately forecast the future some 80 years hence.

But what if the models are correct? Even sort of. Do I want to run the risk of living in a polluted world, one where the oceans are acidified and biodiversity destroyed? Or in a hotter Sydney, already a bit over baked for my liking? Emphatically not!   So what should be done, if anything, to counter this uncertain downside risk? By whom, when and by how much? These are difficult questions that demand political solutions, decisions that can only be informed at the margins by science. So let’s make sure that our advice to policy makers is honest and open to scrutiny – we need more debate not less on this subject.

In the meantime, and returning to the theme of the rising cost of natural disasters, adapting to the current climate variability would be a sensible place to start. Any gains achieved would put us in good stead for whatever climate change might eventually throw at us. So for starters let’s stop building in inappropriate areas and subsidising insurance premiums for those who chose to build in harm’s way.

And if we are truly looking at decarbonising the economy must nuclear energy really be off the agenda?

[Dr John McAneney is Professorial Fellow in the Department of Geography and Environment of Macquarie University, Sydney, Australia and the MD of Risk Frontiers, an R&D company based at the same university and which studies natural disasters. He is the author of Shifting Sands, a novel dealing with corruption in a scientific institution.]