Efforts to suck carbon from air must be ramped up

WASHINGTON (AP) – The nation needs to ramp up its efforts to suck heat-trapping gases to a new climate change report, a new U.S. report said.

The report Wednesday from the National Academy of Science says technology has become better, and climate change is worsening. By mid-century, the world needs to be replaced by 10 billion metric tons of carbon dioxide each year. That's the equivalent of the U.S.

Last year the world was nearly 37 billion metric tons of carbon dioxide in the air, and emissions have been rising.

Steve Pacala, Princeton University biologist and chair of the panel, said in an interview that "the easiest way to remove heat-trapping gases from the atmosphere would be" much easier. "

"It causes one to think about the climate problem when you have a backstop," he said. "And the ultimate temperature we have to go through."

The report comes on the heels of a United Nations science report that painted a picture of the world's ability to avoid dangerous warming. Wednesday's study, "said Kate Gordon, a research fellow at the Columbia Center for Global Energy Policy who was not part of the report's panel.

The 370-page report called for the nation to invest in technologies and methods that would remove the heat-trapping gasses like carbon dioxide from the atmosphere that is generated from transportation. The technologies outlined include the simple and the futuristic:

– Plant more trees and manage forests better, and limit the amount of land used by people. Plants take carbon dioxide from the air and use it to grow.

– Can be kept better so they can store more carbon dioxide and produce more food.

– Conserve and restore coastal plants, like marshlands and sea grass beds.

– A relatively new technology called direct air capture. Pilot projects have started using giant fans that pull in air, use a chemical reaction to suck carbon out, and then inject it underground.

– A still-to-be-worked out technology that links certain types of rock that can absorb carbon dioxide.

Burning more biofuel – like wood – and capturing the carbon dioxide after burning and burying it underground

"These technologies will definitely have a lot of success," said Nobel Prize-winning atmospheric chemist Mario Molina of the University of California San Diego, who was not part of the report's panel.

The study was co-authored by Christopher Jones, an engineering professor of Georgia Tech.

Pacala said the natural methods like tree planting is pretty cheap and available now. But he said they can only do so much because "there's a limit to available land."

Jason Furtado, a meteorologist professor at the University of Oklahoma who was not part of the report, called the bioenergy method the most promising, but not necessarily the easiest.

The direct air capture, being used by Climeworks, Carbon Engineering and others, is mostly limited by cost, Pacala said.

Carbon Engineering acting chief scientist David Keith, a Harvard University professor, said removing carbon from the air. "The idea that humanity could continue huge fossil (fuel) emissions while simultaneously balancing them with removal is nutty – you plug the leaks before bailing the boat."

The report addresses concerns that it creates a "moral hazard" – an understanding of the issue of carbon-removal technologies that could give civilization an excuse to cut emissions, coal and oil. Pacala said carbon removal technologies are not a substitute for massive reductions in carbon emissions. They are tools to get overall emissions down, he said.

"The fact that we need large-scale negative emissions we have left it too late to solve the problem," said Norwegian scientist Glen Peters, who tracks global carbon emissions.

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Follow Seth Borenstein on Twitter: @borenbears.

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The Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.