Wednesday, April 8, 2009

Bushfire imaging to determine global warming risks

By Rachael Brown for The World Today

ABC News Online, 9 April 2009

In an attempt to determine which areas of the globe will be most affected by climate change, US scientists are using thermal satellite imaging to help map global wildfires, with Victoria's recent deadly fires feature in the research.

But the paper's authors say that despite fire being a major by-product of climate change, it is often missing from global warming debates.

The findings, published in the journal PloS ONE, predict climate change will cause major shifts in global fire patterns and that it will happen fast.

Researchers used thermal infrared satellite data of fire behaviour between 1996 and 2006.

The study's author, Max Moritz, a wildfire specialist at the University of California, Berkeley, explains there are not too many areas unaffected.

"The world's deserts tend to be fire free and the equatorial rain forests and then the very high latitudes, close to the poles, tend to be relatively fire free but as you move away from those areas, you find more fire prone parts of the planet," he said.

Researchers looked at the relationship between the affected regions, and climate variables, like fuel loads and weather conditions, and they have plotted what changes the planet can expect if drastic cuts in greenhouse gas emissions do not occur.

Assistant Professor Moritz admits it is just one model, and whole suite would be needed to confidently pinpoint areas most at risk.

The preliminary results reveal regions like north-east China and central Africa may become less fire prone in the coming decades.

He says this finding will surprise those who assume global warming will always equate to more fire.

But he expects there will be hotspots of fire invasion like those forming in parts of the western United States and Tibet.

"Say the Tibetan plateau or the real equatorial rainforest belt or up in the high boreal regions of Eurasia. We do see increases of a broad areas like that but I think one of the more striking take-home messages is about the rate of change that we see some of these patterns shifting," he said.

"So even in the near term, projections from 2010 out to 2039, just the next couple of decades, we see some fairly extensive shifts in some places increasing and some places decreasing."

Geosciences Professor Katherine Heyhoe from Texas Tech University says this year's devastating bushfires in Victoria are a prime example of this rapid change.

"I don't think anyone expected the type of event that you experienced," she said.

"As the Bureau of Meteorology said, it is impossible to attribute any one event to climate change but the conditions that were experienced during that time, were certainly consistent with what we expect to see from climate change over the coming decades."

"Namely shifting rainfall patterns, extended drought and massive heat waves."

Professor Heyhoe says while the study does not have any practical applications in predicting specific fires, it is provides a useful tool to manage what areas are most at risk.

"It is almost like one of those whole body scans you can get when you go to the doctor where you get a scan of your whole body and what that does, is it identifies certain places in your body that might present problems for you and so then you go to a specialist to try to figure out what is wrong with your joint or what is wrong with your heart or your hand," she said.

"So what our study is like, it is like that whole body scan of the world to identify where some potential hot spots are in terms of changes in wildfire activity and to inform regional studies.

She says while some climate change is inevitable, there are many choices that can be made now to limit its impact.

However Professor Moritz says fire is often left out of global debates on climate change.

"Fire is going to be playing a bigger role in carbon cycling, altering air and water quality supplies across the whole planet. In altering habitats so basically we need to think about integrating fire into how we plan," he said.

"We are not necessarily integrating fire into most of our climate change studies in as rigorous a way as we could and in fact, we don't even have a fire chapter in the IPCC - the Intergovernmental Panel on Climate Change and I think that these are directions that we could go to more comprehensively include fire as an agent of change in altered climates."

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