At the end of one of the most bizarre weather years in US history, climate research stands at a crossroads.
After extreme weather events like the drought in Texas and the floods in New England, scientists say they could, in theory, do a much better job of answering the question: “Did global warming have anything to do with it?”
However, for many reasons, efforts to put out prompt reports on the causes of extreme weather are essentially languishing. Chief among the difficulties that scientists face is that the political environment for new climate-science initiatives has turned hostile and, with the federal budget crisis, money is tight.
So, as the weather becomes more erratic by the year, the public is left to wonder what is going on.
When last year ended, it had seemed as if people had lived through a startling year of weather extremes, but in the US, if not elsewhere, this year has surpassed that.
A typical year in the US features three or four weather disasters whose costs exceed US$1 billion each, but this year, the National Oceanic and Atmospheric Administration (NOAA) has tallied a dozen such events, including wildfires in the Southwest, floods in multiple regions of the country and a deadly spring tornado season — and the agency has not finished counting. The final costs are certain to exceed US$50 billion.
“I’ve been a meteorologist 30 years and never seen a year that comes close to matching 2011 for the number of astounding, extreme weather events,” Jeffrey Masters, a co-founder of the popular Web site Weather Underground, said last month. “Looking back in the historical record, which goes back to the late 1800s, I can’t find anything that compares, either.”
Many of the individual events this year do have precedents in the historical record and the nation’s climate has featured other concentrated periods of extreme weather, including severe cold snaps in the early 20th century and devastating droughts and heat waves in the Dust Bowl era of the 1930s.
However, it is unusual — if not unprecedented — for so many extremes to occur in such a short span. This year’s calamities included wildfires that scorched millions of acres, extreme flooding in the Upper Midwest and the Mississippi River valley and heat waves that shattered records in many parts of the country. Elsewhere, huge floods inundated Australia, the Philippines and large parts of Southeast Asia.
A major question nowadays is whether the frequency of particular weather extremes is being affected by human-induced climate change.
Climate science already offers some insight. Researchers have proved that the temperature of the earth’s surface is rising, and they are virtually certain that the human release of greenhouse gases, mainly from the burning of fossil fuels, is the major reason. For decades, they have predicted that this would lead to changes in the frequency of extreme weather events and statistics show that has begun to happen.
For instance, scientists have long expected that a warming atmosphere would result in fewer extremes of low temperature and more extremes of high temperature. In fact, research shows that about two record highs are being set in the US for every record low and similar trends can be detected in other parts of the world.
Likewise, a well-understood physical law suggests that a warming atmosphere should hold more moisture. Scientists have directly measured the moisture in the air and confirmed that it is rising, supplying the fuel for heavier rains, snowfalls and other types of storms.