The causes and consequences of global warming are still debated. But few still dispute its existence. According to NASA, 2005 was the warmest year since the late 1800s. The next four warmest were 2004, 2003, 2002 and 1998. The last time the Earth was this warm, by many estimates, was 100,000 years ago.
Scientists point to disturbing signs: The melting of glaciers and the polar ice caps. The migration of animals, worldwide, to higher, cooler altitudes. The drop in nighttime temperatures across America during the three-day jet grounding following Sept. 11. The deaths of overheated coral reefs. The documentary film "March of the Penguins" spotlighted how global warming makes it more difficult for penguins and their chicks to survive the trek to nursing grounds.
Whether recent changes to the Earth's climate are the result of naturally occurring climatic cycles is pretty much the only question people are still asking. If the shift is as man-made as Australian scientist Tim Flannery argues, we've gotten ourselves into big trouble.
Flannery is the author of "The Weather Makers: How Man Is Changing the Climate and What It Means for Life on Earth," a new book that explores global warming.
Flannery believes world leaders who decline to take immediate action are fiddling while Rome burns.
The over-reliance on fossil fuels by the industrial world's "weather makers," Flannery says, could set off the eradication of 95% of the Earth's species. Flannery blames fossil fuels for 80% of the Earth's warming, and argues that unless oil, coal and gas are replaced quickly -- by green technology such as solar energy and hybrid cars -- hurricanes and floods could wreak havoc on the East Coast.
"This is no part of any known cycle," said Flannery, a burly Australian scientist who is a professor at the University of Adelaide and likes to be photographed in full bush regalia.
"We know how the cyclical climate works. It's related to the way the Earth moves around the sun. Those cyclical changes are highly predictable. They should be driving the Earth into a new cooling phase. Instead they're doing the opposite."
Flannery's views are likely to resonate in California, which has become a battleground over efforts to curb greenhouse gases. Concerns over greenhouse gases prompted the state to implement a pioneering law in 2002 requiring "feasible and cost-effective" emissions curbs. Since then, Maine, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Washington and Oregon have adopted similar curbs.
