Monday, October 12, 2009

Climate change and natural disasters

(See separate article in Green Left for information about contributing to help flood victims in the Philippines)

People in the Philippines are struggling to rebuild after Typhoon Ketsana on September 26 caused widespread flooding and landslides. This has caused a humanitarian catastrophe overshadowed in the Australian media by the terrifying, and equally devastating earthquakes and tsunamis in Samoa and Indonesia.

Millions were affected by flooding in the Philippines, and hundreds of lives lost, after the typhoon dumped enormous amounts of rain on the Philippines on September 24, causing widespread flooding. The storm strengthened as it moved over Indochina, where it caused further flooding and deaths in Vietnam, Cambodia and Laos. The death toll is variously estimated at nearly 400 across the region and may turn out to be higher. More deaths occurred when Typhoon Parma struck the Philippines a week later, exacerbating the situation. Currently, some 400 000 people around the capital, Manila, are living in emergency shelters.

Meanwhile, hundreds more have died in southern India in the worst floods on record which began on October 5. Areas that were recently suffering terrible drought in Andhra Pradesh and Karnataka have been flooded as the Krishna river overflowed. “About 400 mm of rain took place in three days. This has never happened before in India Meteorological Department (IMD) records,” said S.P. Kakran, senior official in the ministry of water resources, in the October 7 Hindustan Times. Dr Santosh Kumar of the National Institute of Disaster Management was also quoted, saying that “This should be studied, whether there is a link between this and climate change.”

Loading the climate dice

Climate change denialists like to point out that weather events such as typhoons are caused by such a diverse range of factors that it is impossible to say that such events are caused by climate change. But true as this may be, warming ocean surface temperatures are one major contributor to the strength of tropical storms, just as warming contributes to drought and other weather crises.

Australian climate scientist David Karoly explained this to the February 9 ABC Lateline show: “It's very difficult to attribute a single event to climate change or to natural variability. What we have to do is really look at the balance of probabilities or the risk or likelihood of these events.... it is possible to get extreme events like [the Black Saturday fires] just due to natural variability. But what we're seeing now is that the dice have been heavily loaded so that the chances of these sorts of extreme fire weather situations are occurring much more rapidly in the last 10 years due to climate change. So climate change has loaded the dice.”

Following the 2005 Hurricane Katrina that devastated the US Gulf coast, debate raged about whether climate change had influenced the storm’s development. Katrina was one of only three Category Five Hurricanes that have made landfall in the US since records began. In 2006, researchers at the Lawrence Livermore National Laboratory (LLNL, a US government-funded research institute) found that human-induced warming should be blamed for at least part of the development of Katrina. LLNL climate scientist Benjamin Santer said in a press release “Natural processes alone simply cannot explain the observed sea surface temperature increases in these hurricane breeding grounds. The best explanation for these changes has to include a large human influence.” Regardless of the controversy over the causes of Katrina, there is widespread scientific agreement that global warming increases the likelihood of more frequent and severe storms.

Local environmental protection

A September 29 statement by the Philippines socialist party Partido Lakas ng Masa (PLM) calls on the government to protect the environment to prevent future disasters. The PLM demands the government “immediately put a halt to all mining, quarrying, and logging activities in the mountainous regions. With denuded forests and damaged mountains, flooding and mudslides will torment lowland communities.” The statement also demands the government cut greenhouse emissions, blaming emissions for “much stronger storms and droughts worldwide.”

Action on local environmental problems like land clearing is an important measure in many areas to lessen the impacts of changing weather. The presence of forest cover can help to soak up rainfall and slow water flows, as well as stabilising steep slopes at risk of landslides. Measures such as these are important around the world. In drought-stricken southeastern Australia, reforestation could have significant benefits for water security. Research suggests that for Melbourne, ending logging in water catchments could see an extra 65 billion litres annual inflow to dams after 60 years. This is because mature trees draw far less water than younger regrowth.

University of Queensland scientist Clive McAlpine says that “the current drought has been made worse by past clearing of native vegetation.” In a 2007 press release, McAlpine explained “the 2002-03 El Nino drought in eastern Australia was on average two degrees Centigrade hotter because of vegetation clearing… Protection and restoration of Australia's native vegetation needs to be a critical consideration in mitigating climate change.” Other recent research comparing northern Australia to the Congo, which has a forested interior, suggests that forests themselves – especially at the coast – create winds and help carry moisture inland.

This has ramifications beyond water use. “The “bulldozer solution” of clearing large tracts of bush to reduce the risk of bushfires will only compound the problem – by clearing the land, you get a hotter land surface, so bushfires will be more severe,” McAlpine said in the August edition of Ecos magazine.

Poverty exacerbates climate disasters

Disasters such as the flooding in the Philippines and India, as well as the are exacerbated because they hit poor areas with inadequate infrastructure and emergency resources. According to ABC News’ Sally Sara, many buildings in the flooded areas of India “are of limited quality mud brick, so people have not been able to get up onto rooftops and seek shelter as others have in more established towns.” The Oct 7 Times of India states that 250 000 houses have either collapsed or have been damaged, and 18 million people are affected. As the flood waters recede, water-borne diseases set in due to lack of clean drinking water. The final human toll of these events could be enormous.

There have already been too many such natural disasters this year, including the Black Saturday bushfires that devastated Victoria in February. And the forecast for years to come is worsening. A UK government report has found the rate of climate change is already worse than the worst-case scenarios forecast in 2007 by the UN's Intergovernmental Panel on Climate Change (IPCC). According to the report, the earth could warm by an average four degrees by 2060 if the world continues its current path. This average would include up to 15 degrees in the Arctic, ten degrees in parts of Africa, and would likely see greatly reduced rainfall in coastal Australia and many other areas. Sea levels would rise, greatly increasing the impact of flooding in coastal areas. The typhoons, floods and bushfires of the future are not looking good, unless drastic measures are taken to reduce greenhouse emissions.

(This article was published slightly edited in Green Left Weekly #813, 14 October 2009)

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