Cyclones and Climate Change - The Deadly Legacy of Oil

In the aftermath of Cyclone Nargis in Burma , the world’s attention is rightly focused on the unfolding human tragedy.

This storm is already one of the deadliest cyclones of all time, with up to 100,000 people loosing their lives, and another 1.5 million left destitute and homeless.

The incompetence and corruption of the Burmese military regime is exacerbating an already gruesome situation. The impact of the storm was also made worse by the fact that much of the coastline had been denuded of trees, making areas more vulnerable to the deadly storm surge.

But what about the storm itself? Sadly, it seems we can expect many more tragedies like this in the future as human induced climate change proceeds apace.

Nargis was the first named storm of the 2008 North Indian Ocean cyclone season , forming on April 27 in the central Bay of Bengal. Nargis rapidly intensified to attain peak winds of at least 165 km/h (105 mph) on May 2; the Joint Typhoon Warning Center assessed peak winds of 215 km/h (135 mph) - making it a rare category 4 storm.

Sea surface temperatures were over a full degree Celsius above average in the region where Nargis intensified before landfall, as can be seen from this May 1 National Oceanographic and Atmospheric Administration satellite map.

Cyclone Nargis was close to a “perfect storm”. According to Mark Lander , a meteorology professor at the University of Guam. “When we saw the (storm) track, I said, 'Uh oh, this is not going to be good. It would create a big storm surge. It was like Katrina going into New Orleans."

The storm pushed a 12 foot wall of water onto the densely populated Irrawaddy delta in central Myanmar. The result was the worst disaster ever in the impoverished country.

It is impossible to link any single storm to climate change but there is mounting scientific evidence that our warming world will produce more intense storms such as Nargis, with a predicable human toll. Last year, Cyclone Sidr slammed into Bangladesh, killing as many as 10,000 people and leaving 20,000 homeless.

"While we can never pinpoint one disaster as the result of climate change, there is enough scientific evidence that climate change will lead to intensification of tropical cyclones," said Sunita Narain, director of the Indian environmental group Center for Science and Environment.

"Nargis is a sign of things to come," she said. "The victims of these cyclones are climate change victims and their plight should remind the rich world that it is doing too little to contain its greenhouse gas emissions."

The science is already there. The 2007 report of the Intergovernmental Panel on Climate Change (IPCC) had clearly observed that cyclones will increase in their intensity as a result of global warming. According to the IPCC: “There is observational evidence of an increase of intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures.”

The IPCC also noted that based on a range of models, it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical sea surface temperatures.

Professor Kerry Emmanuel of the Massachusetts Institute of Technology reported in the journal Nature in 2005 that warmer oceans worldwide are making devastating storms such as Hurricane Katrina more likely by making cyclones on average more powerful and longer lasting. He found that the destructive power of tropical cyclones worldwide had increased by 70% in the last 30 years.

Another paper was published in the prestigious journal Science , backing up Emmanuel’s disturbing findings. These researchers found that the number of deadly Category 4 and 5 storms worldwide has almost doubled in the last 35 years.

This is no act of God. The authors of both these papers attributed this disturbing trend at least in part to human-induced climate change.

Imagining cyclones becoming more powerful is like imaging Cher with a more flamboyant wardrobe. Even an average sized hurricane packs 200 times more energy than the electrical generating capacity of the entire planet.

While this cold statistic is hard to imagine, the physical evidence of that massive power sadly is not. As the human tragedy unfolds in Burma, we should remember that these grim disasters are becoming more likely due to our warmer world - and our continued addiction to fossil fuels.

This was published on Desmog Blog on May 9, 2008