Climate change will cost us all

Climate change will cost us all

14 August 2010

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Australia — You don’t have to be Lord Stern to see how the costs of climate change are already compounding and spiralling, out of control.

Some costs are relatively benign – such as the devaluation of waterfront properties in Byron Bay as sea levels rise – a process starting in earnest whether estate agents like it or not.

Other costs are terrible, such as the conservative $4.4 billion figure put on last year’s Black Saturday fires by the Victorian Bushfires Royal Commission, including insurance claims of $1.2 billion (property and vehicles), $1.1 billion spent by the Victorian Bushfires Reconstruction and Recovery Authority, $658 million in destroyed timber, 173 lives lost worth $645 million according to established formulae (not counting injuries) and about $593 million spent on firefighting (not counting volunteers).

Climate change features minimally in the Commission’s final report, handed down a fortnight ago. That is interesting in itself, because when he announced the inquiry the Premier, John Brumby, said everything would be on the table, including climate change.

The Commission’s interim report last August was silent on climate change – many letter writers to The Age in Melbourne raised this glaring omission – but flagged the issue would be dealt with in the final report.

In September 2009 the commission took expert evidence from CSIRO principal research scientist Kevin Hennessy. He was asked seven questions, including whether climate change was a factor in the extreme fire conditions on Black Saturday, and how often such conditions might occur over the next 10-40 years.

Except perhaps in the darkest sceptic circles, it is uncontentious that climate change was a contributing factor to the dangerous weather experienced that day – although Hennessy pointed out that a forensic ”detection and attribution” study, as was carried out after the European heatwave of 2003, would need to be done to determine the degree of that contribution.

The Commission’s final report notes it “took limited evidence on the subject of climate change because it was persuaded by Mr Hennessy’s conclusions [which] are consistent with the opinions of the Bureau of Meteorology and CSIRO, Australia’s leading climate science agencies.”

Dangerous fire weather is generally measured by the Forest Fire Danger Index, which takes in temperature, rainfall, humidity and wind speed.

The 1939 Victorian bushfires that burnt more than 400,000 hectares were given an index score of 100, now called ”catastrophic”. In some locations on Black Saturday, the index reached 170 and higher.

According to a 2007 study by CSIRO, the Bureau of Meteorology and the Bushfire Cooperative Research Centre, catastrophic days occurred at only 12 of 26 locations across south-east Australia (the triangle below a line from Brisbane to Adelaide) for which good records are available, back to 1973. At four places, the frequency was one occurrence in eight years or less.

The study, which formed the basis of Hennessy’s evidence to the Royal Commission, then looked at various global warming scenarios to 2020 and 2050, using low and high greenhouse gas emissions projections.

On top of a warming of 0.7 degrees to 1990, compared with pre-industrial levels, the ”low” emissions projection assumed 0.4 degrees of warming by 2020 and 0.7 degrees by 2050, keeping total warming to 1.4 degrees. The ”high” warming projection assumed 1 degree of additional warming by 2020 and 2.9 degrees by 2050, taking total warming to 3.6 degrees.

Says Hennessy: “Given that global warming over the last 15 years has been tracking the mid to high [Intergovernmental Panel on Climate Change] range, the projections for fire weather are more likely to be closer to the high global warming range than the low global warming range.”

Cutting to the chase, the scariest numbers are these: by 2020, under the high warming scenario, catastrophic fire weather days will occur at 20 sites, and at seven of those the frequency will be every eight years or less. By 2050, catastrophic days will occur at 22 sites, and at 19 of those the frequency will jump to every eight years or less. So that’s catastrophic fire weather occurring at almost double the sites.

In seven places (Bourke, Ceduna, Laverton, Melbourne airport, Mildura, Wagga and Woomera) catastrophic fire days could occur every three years … or less, the expert witness report concludes.

These figures predict an increase in the frequency of catastrophic fire weather, not fire occurrence, which would be influenced by fuel load and land-clearing and ignition. But the risk is plain.

Hennessy won’t speculate as to why the Royal Commission’s final report said so little about increased bushfire risk due to future climate change. “It was included in my evidence and I tried to emphasise that while the damage associated with the Black Saturday fires was extreme, we can expect more of this in the future,” he says.

For those who think we’re going to hell in a handbasket, it’s all too hard and can’t be stopped, Hennessy’s figures are a wake-up call: ”low” warming (beneath the so-called 2 degree guardrail) is much safer than ”high” warming (3 or 4 degrees, which is where we’re heading based on the world’s post-Copenhagen pledges).

And that’s just bushfire risk. The Insurance Council of Australia puts bushfire claims by value at just 7 per cent of total natural disaster claims between the years 1967-1999, smaller than flood (29 per cent) severe storm (26 per cent), cyclone (25 per cent) and earthquake (13 per cent). But those figures are based on a 2001 study which Hennessy says do not include area burnt or lives lost.

Earlier this week Professor Peter Hoppe, head of insurance company Munich Re’s geo risks research unit, warned that the incidence of natural catastrophes had doubled over the last 30 years, and global warming was the only logical explanation.

There were 828 ”weather catastrophes” – including heatwaves and fire, floods, landslides and storms (stripping out geophysical events such earthquakes and tsunamis) – compared with 317 in 1980. The average number of annual disasters has increased from 339 in the 1980s to 547 in the 1990s and 693 between 2000 and 2009.

As the post-Copenhagen malaise over climate deepens, plenty of people have observed it’s going to ”take another disaster” – such as Hurricane Katrina – to drive genuine public concern and action to beat global warming.

At this rate, there will be a smorgasbord of disasters to choose from, with heatwaves from New York to Tokyo, drought bushfires in Russia and the floods in Pakistan.

But in Australia, after Black Saturday, surely we’ve had enough disaster already?

We may not yet have been able to count on society’s general foresight and goodwill in tackling climate change. What we can count on is fear. When that takes hold, watch out.

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