The Time Is Now, Climate Experts Warn

"I try not to talk about a threshold of two degrees," Schneider added. "At 1.8 the world is not fine. At 2.2, we don't turn into a climatic pumpkin. We just have more severe events. The object is not to get hung up on the numbers. The object is to get out there and get solutions."

Others agreed.

Nevermind the Tipping Point

"Time is of the essence here. I don't know if targets like 350 ppm are that useful," said John Harte of the University of California, Berkeley. "We can't make a regulation on something we can't control. We don't regulate temperature, and we don't even regulate the amount of CO2 in the atmosphere. However, we control what our automobiles look like. We control the efficiency of our devices. We control what our energy looks like."

"I'm not so enthused about the concept of the tipping point," he added. "My view is that we've probably passed some tipping points. We've entered some realms of irreversibility. There are probably many more, but we don't know where they are."

"We know that if we don't take action, it will be a disaster," he said. "That's all we need to know."

Whether they focused on thresholds or not, the scientists all agreed that the problem is urgent and that not doing anything will lead to disaster: rising sea levels, food shortages, spread of infectious diseases and extinctions.

Starting From Here...

Hansen argued that to achieve the target of 350 ppm, we need to put a moratorium on new coal-fired power plants and phase out burning coal without capturing and storing the carbon.

While scientists agree that coal is a huge part of the problem, they also emphasized the need to apply every available sensible strategy to address the problem.

"There seems to be an emphasis on coal and a distraction from other things we can be doing as well," NASA's Zwally said.

"Some people think that climate change is just about saving a few rare species, and it's just environmentalists making a fuss," Frelich said. "That's really not it."

"It's really about the quality of life for people," he continued. The Earth has been through many big changes before. There have been big extinctions, and new species have evolved to fill the ecosystems. It's not a big deal to the Earth's ecosystems, but it will be a really big deal for the quality of life of humans."

Frelich points out that right now the best soil for growing crops in the United States aligns ideally with the right climate for agriculture. But if the favorable climate moves north, it will be over Canada in an area where bedrock lies at the surface, stripped of soil by the last glaciation.

"If the best climate for growing crops lines up with the Canadian shield, that's an issue for people," he adds.

The scientists also pointed out that countries that tackle this most aggressively will be the winners, regardless of what other nations have committed to.

"The economic giants of the rest of this century are going to be the nations that are selling wind turbines and solar panels and efficient cars to the rest of the world," said Harte. "I would think we'd want to be the leader in that."

"Solving this problem is technologically and economically not that difficult," Harte added. "It's proving to be politically difficult."

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Related Links:

Discovery News blog: Environmental Case

Hansen's Testimony to Congress

How Stuff Works: Climate Change

Discovery Earth Live