A Harvard expert has come up with an idea that could revive the Ice Age in a snap and end global warming. It's just one of a handful of "geo-engineering" schemes dreamed up by experts to chill our warming planet and ward off the devastation wide-scale melting could cause.

The concept essentially mimics volcanic eruptions. It would be relatively cheap -- at least compared to the $2 trillion in annual repairs that climate change might cause by the year 2030, according to a recent report by David Keith, Harvard University's Gordon McKay Professor of Applied Physics.

It'd also be a quick fix, guaranteed to lower global temps because there's proof it works, Keith contends.

Volcanic proof

Mount Pinatubo's 1991 eruption in the South Pacific showed that particulate matter shot into the atmosphere cools the planet. The big blast blanketed the earth with sulfuric acid haze, enough to lower temperatures in the Northern Hemisphere a full degree Fahrenheit -- and 0.7 degrees worldwide -- in the following months.

Keith says large aircraft could sprinkle particulates that would limit sunlight penetration into the stratosphere. Perhaps those would be sulfates similar to what volcanoes unleash, creating a chemical umbrella over the Arctic and other select locales where ice is melting.

Such "solar radiation management" might come with troubling consequences, but the alternative may be worse. Global warming will melt sizeable portions of the ice caps and rising sea levels and devastating to cities by the shore, Keith said in a 2007 talk.

Alaska has become all too familiar with those costs, as it weighs what to do about more than 30 eroding villages, such as Kivalina, that could one day wash away. Relocating them will cost hundreds of thousands dollars per resident, raising questions about the role public funds should play in moving towns.

Progress reducing CO2: 'Zip'

Keith says his fix would come decades faster than lowering carbon dioxide emissions, an effort that's gone nowhere despite decades of warning. "We've known about this problem 50 years ... and we've accomplished close to zip," he said.

Others climate change observers, including Alaskans, are frosty to his concept. They say it could unintentionally worsen warming and distract people from addressing the core problem: rising greenhouse-gas emissions.

NASA climatologist Claire Parkinson wrote a book two years on the topic in which she picked apart some of the geo-engineering concepts. In "Coming Climate Crisis? Consider the Past, Beware the Big Fix" Parkinson says she isn't sure warmer temperatures will cause the calamity some fear. North Country residents – including Alaskans shivering through 50-below cold this winter -- may even think that a little warming is a good thing.

At any rate, since we don't know how climate change will play out, is it worth tricking the earth with schemes that could produce unknown risks?

"This particulate matter won't just stay up there," she said. "It could descend and cause health problems and it could lead to other chemical reactions. It could lead to something different altogether. We just don't fully understand what it will do."

Keith couldn't be reached for this article. An assistant said he's on a ship headed toward Antarctica for a secluded family getaway. Keith, who apparently really likes the cold, once called the heat-management idea "absurdly cheap." It would cost no more than $8 billion to acquire the aircraft and spread 5 million metric tons of material into the sky 20 miles above the Earth, according to one report. Annual bursts of 3 million metric tons would be enough to counter anticipated greenhouse-gas emissions in the next half century.

As he joked in his 2007 TED Talks presentation: "We could create an ice age at a cost of .001 percent of GDP. Not that we'd want to."

But the concept should be studied, he urged in his report. Predictions about the consequences of climate change, such as increasing heat and glacier melt, have undershot their mark. It's worth knowing the risks of implementing "solar-radiation management," just in case the world is one day confronted with the need to take emergency action.

Reduce CO2 first

Stephen Gray, director of the Interior Department's Alaska Climate Science Center, said that experimental idea and others should be on the table for discussion. But not at the expense of reducing carbon dioxide emissions by using alternative energy.

"If you're interested in doing something about climate change there are lot of options related to increasing energy efficiency, or changing the type of emissions we produce, things that we know we are going to have a positive impact without resorting to some of these more exotic ideas," said Gray.

And there is no shortage of "exotic" ideas out there. One off-the-wall proposal suggested by geo-engineers involves fertilizing nonproductive areas of the ocean with iron to stimulate plant growth that absorbs and traps atmospheric carbon dioxide. Gray doesn't like that one, either.

"I'd be more than reluctant to send someone out there with a cargo ship to dump iron in the ocean," he said.

Other strategies include:

Cloud-whitening: Pumping sea spray into the sky to create whiter clouds that reflect sunlight, with some pump stations situated on Bering Sea islands.

Damming up the Arctic Ocean: This could include a Bering Sea dam more than 150 miles long between Russia and Alaska, starting south of the Yukon Ruver, extending to St. Lawrence Island, and from there extending farther to Russia. It would trap Yukon River freshwater so it mixes with the Arctic Ocean, thus reducing ocean salinity and increasing the propensity for freezing.

Sunshields: Reflect away some of the sun's intense light by putting an object -- maybe a large lens or trillions of little discs -- into space about a million miles above the earth.

Alaskans focused on real-life issues

Alaskans aren't working on such geo-engineering dreams, said Gray. They're too busy dealing with the real-life consequences.

"It's fine to speculate about these grand ideas in the setting where I'm sure this gentleman (Keith) operates, but when we're seeing village infrastructure fall into melting permafrost or impacts from storms … we're dealing with more practical matters," he said.

John Walsh, director of the Center for Global Change at the University of Alaska Fairbanks, said humans don't know enough about the interplay between oceans, earth and clouds to employ tricks such as Keith's.

"There are risks and there can be surprises," he said. "We aren't in a position to say how it would play out. We could conceivably trigger a much bigger loss of ice if there's some sort of feedback loop involved."

Climate change has other negative consequences that Keith's idea won't help either, such as ocean acidification and shifts in seafood availability, said Parkinson, the NASA scientist. The solution that addresses all potential problems is reducing greenhouse-gas emissions.

"I'm not 100 percent sure we're headed toward a disaster, as some people feel we are," she said. "But my net conclusion remains that we need to reduce emissions. And it comes more from the fact that we really don't know all the consequences of what we're doing."

Contact Alex DeMarban at alex(at)alaskadispatch.com