TAMPA — To see global warming in action, look at the world's glaciers.
Not only are they melting, but they're melting faster and faster, says climate change researcher Lonnie Thompson.
"Within a couple of decades, there will be no ice on Kilimanjaro," Thompson told several hundred people Thursday at the University of South Florida.
The highest mountain in Africa, Kilimanjaro in Tanzania, has lost 86 percent of the ice it had in 1912. And 26 percent of the ice there in 2000 is gone now.
Thompson is an Ohio State University researcher and an adviser to the Academy Award-winning documentary An Inconvenient Truth. He has spent decades studying glaciers, measuring the thickness and spread of their ice caps, drilling solid cores of ice and shipping them down mountainsides, sometimes by yak, for scientific analysis.
He is fond of a saying that ice asks no questions, presents no arguments, reads no newspapers nor listens to any debates as it changes from solid to liquid. It just melts.
And it's not just melting in Africa, he said. Researchers have documented shrinking glaciers from Alaska to Peru to Tibet. Glaciers do advance and retreat over time, he said, but it's alarming to see change take place so quickly.
"It's the acceleration that we're really concerned with," said Thompson, the featured speaker on the first day of a two-day USF conference on climate change, the environment and health.
The conference marks the dedication of USF's new School of Global Sustainability, which will begin to offer an interdisciplinary master's degree in global sustainability starting in August.
Thompson said 2005 was the warmest year on record and 2009 was the second warmest. Eleven of the warmest years on record have been in the past 12 years. The 20th century was the warmest of the last 2,000 years.
The evidence suggests that the warming is not, for example, caused by the sun, Thompson said. The stratosphere is cooling, while surface temperatures are getting warmer. Also, temperatures have warmed more during the winter than in summer and more at higher latitudes than at lower latitudes.
If the sun were driving the change, he said, the stratosphere, the summer and the lower latitudes would all be heating up more than they are.
"There's a whole line of evidence that points to the human-driven changes of climate," he said.
To illustrate what would happen if 8 percent of Earth's ice on land melted, Thompson showed the audience maps with the sea covering parts of the Pinellas beaches, as well as much of Florida south of Lake Okeechobee, New Orleans and New York City.
"If you go to a place like the Netherlands, you can forget it," he said. "It's not going to be there."