Well it’s been two months since I posted my last update and the Climate Change and Emergency Preparedness Inquiry is in full swing. As I suspected the reporting date has been extended to the 26th of June (and even that date is still rather ambitious). There are now 338 submissions (most of the new ones being from individuals) and hearings have been held in Melbourne, Brisbane and Perth (the transcripts are available online). Hearings in Sydney and Canberra are scheduled for the next couple of days. I have only skimmed through the content of the hearings and there’s some interesting reading, but I’ll leave it to the inquiry to sum them up in its report.

There doesn’t appear to have been any more recent news coverage of the inquiry.

In related developments the Productivity Commission report on Barriers to Climate Change Adaptation and the associated Government response has been released.

The Climate Commission has also released a new report on climate change and extreme weather. Interestingly it cites new research into a link between heat related fatalities and climate change in Australia (hint: there is one). As far as I’m aware this is the first time any link has been found between present climate change and disaster impacts in Australia – big news given that I’ve previously estimated heatwaves as having the most costly impact of any disaster type. Previous studies have attributed rises in disaster losses to socio-economic changes.

Over in the United States new research by Munich Re has now linked insured losses from thunderstoms to climate change (though I expect there to be discussion about the normalisation methodology). However this study is an outlier – most studies have found no significant trends in current disaster losses.

But most concerning is this report of a new study into rainfall extremes. I’ve often said that whilst climate change impacts on flooding will require improved land use planning, planned retreat and better mitigation, big changes to emergency response will only be needed if there’s changes to the largest flood possible (aka the Probable Maximum Flood or PMF). Unfortunately there hasn’t been any studies at this most extreme end of the scale – until now. It turns out that by the end of the century climate change could substantially increase the probable maximum precipitation (at least in the continental US, by as much as 30%) – the rainfall that gives rise to the PMF.

The PMF is critically important for emergency planning and the siting of infrastructure like evacuation centres, hospitals and schools. More concerning is the possible impact on dams – which are built or retrofitted to withstand the current PMF, but don’t take into account climate change. It was concerns over possible dam failure in a PMF that led to the construction of the auxiliary spillway for Warragamba Dam. If the proposed dam raising of Warragamba is built for current conditions and allows additional development in the valley a PMF under climate change could possibly lead to dam failure – a catastrophe that could kill tens of thousands of people.