DURHAM, N.C. - One of the snowiest U.S. winters in recent history -- coupled with last year's leak of damaging e-mails from a group of climate scientists -- has led some to question whether global warming is nothing but hot air.

Not true, says a Duke University climate scientist.

"There is a reason we call it global warming," says William L. Chameides, dean of Duke's Nicholas School of the Environment and a member of the National Academy of Sciences. "Global temperatures can be warming even if temperatures in the United States are not."

While we've been experiencing wintry extremes, other regions of the world have had to contend with extreme heat waves, he says. These include Australia, Brazil and South Africa.

Even here in the United States, this winter has been exceptional for its snow, but not its cold, he notes. The National Oceanic and Atmospheric Administration's National Climate Data Center reported that January 2010 was the fourth-warmest January on record. Average temperatures in the contiguous United States that month were about a half a degree Fahrenheit above the long-term averages.

"This pattern of warmer temperatures and stronger storms is consistent with climate models that show global warming will bring more extreme weather, specifically more severe storms with greater amounts of precipitation," Chameides says.

The leaked e-mails, in which scientists from the University of East Anglia's Climate Research Unit wrote about using a "trick" to "hide the decline," have given climate science a black eye, Chameides acknowledges.

"The worst thing we climate scientists can do at this point is contend that these issues are inconsequential. They aren't," he says. "Transparency and impartiality are at the heart of the scientific process.

"But it's egregious for climate deniers to exaggerate the problem. A careful, objective, complete reading of the scientific literature reveals the scientific evidence that the globe is warming -- and that this warming is connected to human activities -- remains strong."