What's Behind All The Extreme Weather?
Hurricanes, floods, and record heat. Is the recent spate of extreme weather conditions the result of climate change? As VOA's Rebecca Ward reports, the verdict is still out.
September 15, 2010 8:00 PM
It's been a long hot summer in the northern hemisphere. And along with the heat has come some extreme weather - storms in the Atlantic and Pacific, flooding and forest fires. In Russia, Moscovites wrestled with weeks of record breaking heat, while fire fighters fought devastating wildfires. Massive flooding in Pakistan continues to affect nearly 20 million people, with one-fifth of the country submerged at one point.
You don't need to be a climatologist to know things aren't as they should be.
"We're having our hottest year on record in a hundred and fifty years," says Jay Gulledge, senior scientist on global climate change at the Pew Center on Global Climate Change. "We know there's a long term warming trend that's been going on for the past century. The largest warming has occurred in the last half-century."
Gulledge says no one weather event can be specifically linked to climate change. But he says the trend indicates a relationship between weather and warming.
"If we put more heat in there, we will get more extreme weather, which means droughts, floods, hurricanes, etc. If we put less in, then the problem will not be as bad."
James Carton at the University of Maryland agrees, noting that the latest studies indicate as global warming progresses, the world will likely see extreme hurricanes - categories three, four and five - becoming more frequent.
"The science behind that is quite simple," says Carton. "Hurricanes draw their energy from the evaporation of surface temperatures from the ocean. And as the ocean warms up, and the ocean has been warming up, you can expect more evaporation, therefore more intense hurricanes."
But Patrick Michaels of the Cato Institute warns against focussing on any one data set.
"I am looking at the accumulated energy cyclone index through August of 2010 and it is at its absolute lowest values since it was started to be taken in 1979, despite the fact that the planet is a few tenths of a degree warmer at its surface than it was. So, how strong is this relationship?"
More heat in the atmosphere is blamed on carbon emissions - the kind that results from burning coal, running automobiles and even switching on lightbulbs - pretty much any activity that takes some kind of energy. The more greenhouse gases the world produces, the warmer it gets. But Patrick Michaels says fears surrounding the effects of climate change are overblown.
"If you take a look at the actual rates of warming that are being observed and compare them to the median values produced by the United Nations computer models, you'll find that the observed rate of warming is at or near the low end of the ranges that are being predicted. That should be pretty reassuring. It should tell you that it's not the end of the world, that you have decades to figure what are you going to do about this, if anything."
At the University of Maryland's Center for Environmental Science, Professor James Carton has a different view, saying it isn't just the climate at risk because of too much carbon dioxide.
"As you increase the carbon dioxide in the atmosphere, you increase the acidity of the ocean," he says. "And that is also becoming a serious problem because as the ocean becomes more acidic, they affect the shells of many of our plankton."
Carton says the best solution to a warming world would be to attack the problem directly. The Pew Center's Jay Gulledge agrees.
"At some point, my expertise is in the science, and at some point we're going to reach a level of impacts of climate change that is going to force behavorial change."
You can watch all of Rebecca's "Going Green" reports on the environment by clicking here.