Global environmental challenges
Floods? Droughts? Wildfires? Hurricanes? Yes, there is a climate change connection
For years, climate scientists were circumspect when asked if a specific bit of violent weather — for example, Hurricane Irene, the late-summer storm that slammed the heavily populated U.S. East Coast — could be blamed in some way on climate change.
“Climate is what you expect,” the scientists would say, “while weather is what you get.” They would often go on to say that while increasingly severe weather and correspondingly serious costs and consequences were forecast in climate change computer simulations, there was no way to directly blame a given storm on human-generated heat-trapping gases in Earth’s atmosphere.
There still is no direct line between a certain amount of warming and a certain storm, wildfire, drought or flood. But there is a “new normal,” detailed by scientists on a new website . Staffed and advised by some of the most well-known climate change experts in the United States and elsewhere, the site says plainly that what the computer models foretold in 2007 is clearly documented to be occurring.
“All weather events are now influenced by climate change because all weather now develops in a different environment than before,” the Climate Communication site noted in an article released days after Irene dumped record amounts of rain on the U.S. Mid-Atlantic and Northeast.
“While natural variability continues to play a key role in extreme weather, climate change has shifted the odds and changed the natural limits, making certain types of extreme weather more frequent and more intense. The kinds of extreme weather events that would be expected to occur more often in a warming world are indeed increasing.”
So what has really changed? For one thing, it’s just plain getting hotter, the Climate Communication scientists say, citing U.S. and global statistics.
Sixty years ago, the number of new record high temperatures in the contiguous United States was about the same as the number of new record lows. Now, the number of new record highs each year is twice the number of new record lows, a sign of a warming climate, these scientists said.
Unveiled as wildfires consumed hundreds of homes in Texas and heavy rains swamped parts of New England, the site had its public unveiling as some Republican presidential candidates expressed doubts that climate change was happening — or that humans contributed to it.
Another climate change signal showed up in September’s early days: the National Snow and Ice Data Center reported that Arctic sea ice was at near-record lows in August, with both the Northwest Passage and the Northern Sea route open. The extent of sea ice in August was near the record lows of 2007, when it dipped to its lowest point in the satellite record that started in 1979. Arctic sea ice generally hits its lowest extent sometime in the next few weeks. Stay tuned.
Photo credits: REUTERS/Mike Stone (Flames roar near Bastrop State Park as a wildfire burns out of control near Bastrop, Texas, September 5, 2011)
REUTERS/Lucas Jackson (A man walks down a flooded street in the town of Totowa, New Jersey August 30, 2011)