Scientific consensus has been warning us for years that climate change is real. But the mountain of scientific evidence wasn't enough on its own for the issue to penetrate mainstream debate. For some to be convinced of the coming environmental threats, they needed to feel the heat. Literally.

So with freakishly warm temperatures over the last year, many pundits are now increasingly alarmed over the fate of the planet.

Tom Friedman lamented the daffodils growing off-season in his garden. "Don't know about you, but when I see things in nature that I have never seen before in my life, like daffodils blooming in January, it starts to feel creepy," he wrote in the New York Times. Even Pat Robertson started to care during the excessive heat of last summer. "I have not been one to believe in global warming," he said on a broadcast of The 700 Club in August. "But I tell you, [the blistering summers] are making a convert out of me."

While it is clearly good news that attention, long overdue, is being given to the fact that humans are causing climate change, it is dangerous to use an unseasonably warm winter as evidence of the problem. The reason is simple: The current weather is one of the least compelling bits of evidence for climate change and, in fact, may not be evidence at all.

"Seeing one event--a heat wave in December in Washington or a cold snap in January in Washington--and from that arguing that global warming is or isn't real is not good science," said Richard Alley, one of the authors of the recent Intergovernmental Panel on Climate Change report, in an e-mail to The Nation.

Wycliffe Muga, who covers environmental issues for the BBC and Kenya's Daily Nation, said in an interview that recent warm weather "is purely incidental."

"Studies on global warming indicate that the change in temperature will be very gradual," said Muga. "A not-so-cold winter does not mean much."

Dennis Feltgen, a meteorologist at the National Weather Service, recently told the Washington Post that the unusually warm weather is not a byproduct of global warming but of El Niño. In the same article Alley said, "It's very dangerous to blame climate for weather."

It may also prove to be counterproductive. Imagine if next winter the Northeast is hit with an average snowfall and typically cold temperatures. Will Pat Robertson and his followers be convinced that God has saved us from global warming? Will Tom Friedman's readers take a deep breath knowing there is no strange vegetation in the columnist's garden? Will people still take seriously the coming problems or the urgency with which the world needs to act?

"If next year the temperature is cold, the people who have relied on the weather as evidence will be discredited," Muga said.

One problem is that, at least in the short term, sensationalism works. People are less likely to make sacrifices when a problem seems distant. On the other hand, as Muga notes, "when you relate [global warming] to what happens today, people will be scared into action."

Ana Unruh Cohen, director of environmental studies at the Center for American Progress, reached by e-mail, sees things differently. "Using the strongest scientific evidence is always preferred, but I think you can use weather events to help people understand how a warmer earth will be different and the significant impacts we will experience."

But the actual evidence seems persuasive enough. There is plenty of verifiable data from experts that says global warming is very real and very bad.

§ The IPCC report released February 2, involving leading scientists from 113 countries, concluded that climate change is so severe that it will "continue for centuries" and that, unless curbed, it could cost us more than a million lives by 2100.

§ The Stern Review, released in October by prominent British economist Sir Nicholas Stern, concluded that climate change could have drastic economic consequences. The report called global warming "the greatest market failure the world has ever seen" and predicted that its effects could displace more than 200 million people by the year 2050.

§ Political leaders across the globe have expressed fear at what lies ahead. French President Jacques Chirac said, "We are on the historic threshold of the irreversible." The South African environmental minister, Marthinus van Schalkwyk, said failure would be "indefensible." Alfonso Pecoraro Scanio, Italy's environment minister, said, "While climate change runs like a rabbit, world politics move like a snail; either we accelerate or we risk disaster."

Sounds pretty serious, even without the mention of mysterious daffodils (which, according to the American Daffodil Society, are "quite tolerant of cold" and have been known to grow in January, even in icy conditions).

Clearly, the coming dangers from climate change are grounded in reality. It would be wise to make sure that the dialogue over it is, as well.

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