Stephen Leahy

BROOKLIN, Canada, Aug 31 2006 (IPS) — One year after Hurricane Katrina devastated the U.S. Gulf Coast, a new survey reveals a majority of U.S. citizens now believe global warming is responsible for extreme weather events in recent years.

Most climate scientists have been saying this for some time, but with the proviso that no single event – like Hurricane Katrina – can be conclusively blamed on climate change. Instead, it is the accumulation of evidence over many decades and from many sources that rising global temperatures are likely to result in more and stronger hurricanes in the Atlantic in future.

“The number of named storms is nearly 50 percent higher in the last decade than in the previous four decades,” said Judy Curry, who heads Georgia Tech’s School of Earth and Atmospheric Sciences.

Tropical storms are named when sustained winds reach speeds of 62-117 km/hr, and become hurricanes when wind speeds are higher than 118 km/hr.

Statistically it is clear that in the Atlantic, hurricanes are becoming more frequent and bigger, Curry told IPS. And climate change, which has increased atmospheric and sea surface temperatures, is the likely cause, she said.

Not every scientist agrees. Some argue that a natural cycle called Atlantic Multidecadal Oscillation is responsible for the recent increase in the number of very powerful hurricanes.

However, a paper published this week in Geophysical Research Letters examined this hypothesis and concluded that climate change offered the best explanation for the increases in sea surface temperatures that is fueling increased hurricane activity.

Curry notes that the Pacific, especially the northwestern region of Japan and China, has experienced a record-breaking season of typhoons (another term for hurricanes) this year with the 12th typhoon moving toward East Asia this week.

It has been much quieter in the Atlantic with just five named storms so far this year. That is a sharp contrast to last year’s record breaking 28 named storms, including Katrina, which killed more than 1,800 people and caused an estimated 81 billion dollars in damages.

The National Oceanic and Atmospheric Administration reduced its forecast in August to an expected 12 to 15 named storms, of which seven to nine might become hurricanes.

“There is great deal of year-to-year variability so even if this turns out to be an average year, there will be more and stronger storms in the coming years,” says Curry.

The risk from hurricanes is growing substantially and it makes sense to act now to minimise the potential impacts, she says.

Latin America and the Caribbean will be among those hit hard by the increases in extreme weather events like hurricanes unless there are real changes in development policies, says a report by a coalition of Britain’s biggest environment and development groups, including the New Economics Foundation and the WWF (World Wide Fund for Nature).

“All policies and programmes should face the test of whether they will leave people in Latin America and the Caribbean more or less vulnerable to the effects of global warming,” says the report “Up in Smoke” released this week.

Energy efficiency and renewable power should be made priorities by governments in the region, it says, and urges industrialised countries to cut their own emissions and provide funding and “climate-friendly” technologies to poorer countries.

The World Bank also admitted this week that up to 25 percent of the projects it funds were at risk of failing due to climate change. The impacts of higher temperatures, more variable precipitation, more extreme weather events, and sea level rise are already being felt and will continue to intensify, the Bank said in a release.

“Climate change may be one of the biggest threats to attempts to cutting poverty in the world’s most deprived nations and has forced the World Bank to reassess its development projects,” the Bank said.

Projects in small island states are already being impacted because of rising sea levels and storm surges, which have affected the water supply and infrastructure. Many arid countries in sub-Saharan Africa are bearing the brunt of the damage because of the impact of climate change on crucial farm production, according to the Bank’s report, “Managing Climate Risk”.

The Bank says aggressive mitigation of greenhouse gas emissions is crucial if dramatic long-term changes are to be averted, although most of the changes projected for the coming decades can no longer be avoided.

Adapting to the new era of extreme weather means learning from disasters like Hurricane Katrina.

Katrina was not an especially powerful storm – it just happened to strike a very vulnerable region where natural buffers like wetlands had been removed to facilitate industrial development and where the city of New Orleans was well below sea level.

“For decades, we ignored the potential consequences and allowed the Gulf Coast to become industrialised by the petrochemical industry and others – showing that offshore drilling and other activities have serious onshore implications,” said Sierra Club’s executive director, Carl Pope.

The Sierra Club is calling for restoration of the coastal marshes and cypress forests and closure of the Mississippi River Gulf Outlet. The outlet funneled Katrina’s storm surge right into New Orleans and had previously caused the loss of thousands of hectares of salt marsh.

“We can never know how much a healthy coastal marsh/forest ecosystem could have reduced the storm surge that inundated the city,” said Leslie March, chair of the Sierra Club Delta (Louisiana) Chapter.

“But Katrina showed us once again that protecting the environment is necessary in order to protect human beings, their communities, and our economy,” March said in a statement.