After a long, hot period of drought in eastern Australia, spanning much of the 1990s and 2000s and referred to as the worst in 1000 years (see also discussion on BNC on the drought here and the strange winter of 2009 here), the period 2010-2011 has seen record rainfall and rural flooding events in Australia. This has culminated this week with the 3rd largest city, Brisbane, being struck by severely damaging and costly urban floods, inundating the central business district and overwhelming many thousands of homes and businesses. To quote:

BRISBANE is besieged by the flood of the century, with more than 30,000 properties to be inundated tomorrow… The Queensland capital is now the scene of a natural disaster unprecedented in contemporary Australia. The Brisbane River is due to reach 5.2m on a 4am high tide, 30cm down on the predicted peak, but approaching the mark set in the devastating 1974 floods that claimed 14 lives.

This all comes on the back of an earlier ‘drought breaking’ flood that struck central Queensland earlier in 2010, which I described in this post:

Do the recent floods prove man-made climate change is real? In this post, I said:

Earlier this year in Australia, the Bureau of Meteorology released a Special Climate Statement on the recent exceptional rain and flooding events in central Australia and Queensland. February 28th 2010 was the wettest day on record for the Northern Territory, and March 2nd set a new record for Queensland. Over the 10-day period ending March 3rd, an estimated 403 cubic kilometres (403,000 gigalitres) of rainfall fell across the NT and QLD. Extreme, indeed.

For further background on these events, you should read the latest special climate statement, released on 7th January by the Bureau of Meteorology: An extremely wet end to 2010 leads to widespread flooding across eastern Australia. It says:

It was the wettest December on record for Queensland and for eastern Australia as a whole, the second-wettest for the Murray-Darling Basin, the sixth-wettest for Victoria and the eighth-wettest for New South Wales. For Australia as a whole it was the third-wettest December on record. This followed an extremely wet spring, the wettest on record for Queensland, New South Wales, eastern Australia and the Murray-Darling Basin. The heavy late November and December rainfall followed a very wet July to October for Australia, meaning many catchments were already wet before the flooding rain. It was Australia’s wettest July to October on record and also the wettest July to December on record.

The point of this post is not to try to attribute these extreme weather events directly to climate change, although I think there is a real influence at work here. A major factor is one of the strongest La Niñas on record, as detailed in this excellent piece by climatologist Neville Nichols. Climate scientist Will Steffen from ANU also had this to say:

…there was no direct link between global warming and the tragic flash flooding in Toowoomba which has killed at least nine people in southeast Queensland.

But he told The Australian Online that climate change would lead to heavier, more frequent rain.

“As the climate warms, there is more water vapour in the atmosphere,” he told The Australian Online.

“This means that there is a probability that there will more intense rainfall events around the world.

There is some evidence that we can see them now. I think the place where the best data is the US.”

My point is this. The recent “Big Dry” was almost certainly the most economically damaging climate event ever to strike Australia — certainly for rural areas. Now, on the back of this extended event, which impacted many sectors of Australian business, comes the latest diluvian disaster. Aside from the direct costs of replacing damaged and destroyed goods and rebuilding infrastructure (the insurance estimate I saw on the news today was >$5 billion), there are reports that the cascading effects could wipe 1% off Australia’s GDP — around $13 billion — mainly through export losses.

These are major climate-related costs to the economy, as well as to the welfare of the people caught up in this event and the natural systems that are being damaged.

Then, in Europe and the US, we’ve seen record snowstorms and extremely disruptive cold snaps, which can be linked to extremely unusual events in the Arctic, as described here. And, of course, in 2009 we witnessed the horrific bushfires in Victoria – the worst on record. Again, I repeat, these types of events have happened before, and are difficult to attribute individually to climate change versus random chance — but that doesn’t change the fact they they really hurt, economically and socially.

Climate change, left unabated, will increase the frequency and severity of natural disasters. More and more energy is being trapped within the Earth system (see figure to the right), and it has to be expressed somewhere, sometime. The laws of physical science dictate nothing less. And it will, in turn, hit the Australian and World economy hard. Those economic rationalists among us should heed the reminder that these latest natural events have delivered. Avoided global heating is avoided cost (with the worst-case scenarios being incalculable).

For the general populace’s opinion on climate change, what will the latest events do? I can’t be sure of course, but I suspect that it will, in many, awaken within them a deep-seated horror — “...this could happen to me“. This personal demon, fed by the graphic reporting we now get on such events, might well do more than anything else to catalyst a community consensus for real, effective and urgent action to eliminate fossil fuels.