Green Blog: For Planes, a Climate Antidote: Bypass the Arctic

This year Arctic sea ice reached a historic low, breaking a record set in 2007 by a whopping 18 percent.? Researchers suggest that the ice could disappear entirely in as little as two or three decades. That would accelerate the warming of the planet, given that dark solar-energy-absorbing ocean water would replace a surface of bright white ice, which reflects sunlight back into space.

Air traffic is the biggest source of pollution in the Arctic. Ever since cross-polar flights became commonplace in the late 1990s, flights crossing the Arctic Circle have risen steadily, surpassing 50,000 in 2010.

While cross-polar flights account for only a tiny percent of total global emissions from aviation, the standard cruising altitude for commercial planes in the Arctic is the stratosphere, an extremely stable layer of the atmosphere. Black carbon and other emissions get trapped in this layer and as a result remain in the atmosphere?longer, causing far more damage than emissions from flights at lower latitudes, scientists say.

But with some creative detours, airlines can buy a little more time for Arctic sea ice, a new study suggests.

Writing in the journal Climatic Change, Mark Jacobson, an atmospheric scientist at Stanford University, and other researchers report that rerouting planes around the Arctic Circle could help delay the advent of a tipping point after which the ice would eventually disappear.

The research team gathered emissions data from 40,399 cross-polar flights in 2006 and used computer simulations to compare what would happen over the next 22 years if? those flights skirted the Arctic rather than following their current routes.

Using these less direct flight paths would increase commercial planes? total fuel use by 0.056 percent, their calculations suggest. But global surface temperatures would dip by by nearly three-hundredths of a degree Fahrenheit (0.015 degrees Celsius), they wrote. That?s because the emissions would predominantly be dumped in less stable areas of the atmosphere, where precipitation washes out pollutants, especially black carbon.

Rerouting flights to save the Arctic sea ice would cost about $99 million a year in additional fuel and operational costs globally, the scientists reported. But the climatic savings from avoiding the increase in temperature would be 47 to 55 times that amount for the United States alone by 2025.

Ultimately, Dr. Jacobson warns, the aviation industry will need to make more drastic changes than skirting the Arctic.?Aircraft traffic is on the rise, so it?s not like the problem will go away by itself,? he said.

?We have three options here ? move pollution sources away from sensitive areas like the Arctic; reduce emissions from current fuels, although less of one pollutant usually results in more of another; or we need to change airplane technology so that you don?t use fossil fuels anymore,? Dr. Jacobson said

This third option, which could involve switching to something like cryogenic hydrogen fuel, ?is the only one which isn?t just a temporary fix,? he said. ?Industry doesn?t want to spend the money, but in the end we will have to go there ? it?s just a question of how much damage we inflict before we make the switch.?

Source: http://green.blogs.nytimes.com/2012/12/03/for-planes-a-climate-antidote-bypass-the-arctic/?partner=rss&emc=rss

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