Tuesday, November 9, 2010
Current technology can reduce ship pollution 90%, and a House committee is weighing law to reduce black carbon emissions.
By Lisa Song
In the next few decades, a warming Arctic will open up shorter shipping routes, potentially reducing the amount of fuel needed to travel between ports. But the increased amount of soot in the atmosphere could further accelerate the region's climate change, and the shorter distances won't generate enough fuel savings to offset the impact. (Editor: I do not see the writers proof of statement - therefore it's her opinion - readers are urged to read the cited study below for more details. Power plants generate more black-carbon than all other sources (including ships) combined.)
Those are the key findings of a recent study published in the journal Atmospheric Chemistry and Physics. This new study is the first systematic analysis of how Arctic shipping could affect local climate.
About 15,000 ship trips occur in the Arctic region (north of 60° latitude) each year, but they comprise a small fraction of global shipping. Melting sea ice could create ice-free passages by 2030 and create shortcuts for global trade. Two of the most anticipated routes are the Northwest Passage linking Japan to eastern Canada, and the Northeast Passage along Russia's northern coast, which would connect China with Europe.
Increased ship traffic will bring additional air pollution to the Arctic. Of particular concern is black carbon, a form of particulate matter emitted through the burning of fossil fuels.
"Black carbon is—in my opinion—the second leading cause of global warming after carbon dioxide," said Mark Jacobson, a professor of civil and environmental engineering at Stanford University, who was not involved in the study.
Today's shipping industry produces 42 million tons of carbon dioxide annually, versus only 4 million tons of black carbon. But the cumulative effects of black carbon can add substantially to those of carbon dioxide from Arctic ships: over a short-term period such as 20 years, one ton of black carbon emitted in the Arctic can produce a similar warming effect as 4,000–7,000 tons of carbon dioxide, James Corbett, the study's lead author, told SolveClimate News. Corbett is a professor of marine policy in the College of Earth, Ocean and Environment at the University of Delaware.
Short-Lived But Potent Pollutant
Black carbon warms the earth in two ways. First, atmospheric black carbon absorbs sunlight and heats up the air around it. Particles of black carbon can also fall to the ground and accelerate melting by decreasing albedo, or surface reflectivity. Ice and snow reflect much more sunlight than the ocean, so the more ice that melts, the more water there is to absorb heat. The result, said Jacobson, is a positive feedback loop that will speed up Arctic warming.
Unlike carbon dioxide, which can remain in the atmosphere for 100 years, a single particle of black carbon rarely lasts more than three weeks before it's rained out of the atmosphere and deposited on the ground. (The one exception is black carbon emitted by planes that fly over the Arctic; the planes fly in a higher level of the atmosphere called the stratosphere, where the air is more stable. As a result, stratospheric black carbon can last for months or even years.)
However, Corbett said, the cumulative effect of ground emissions provides a continuous source of black carbon that's transported from populated places like Europe to the Arctic, and the emissions will only increase as sea lanes open up.
Although the new routes would cut down on ships' CO2 emissions, those reductions would be offset by the effects of black carbon, said Corbett. "It won't benefit the Arctic…[because the black carbon emissions] would be in a place where you would least want them."
The Arctic is particularly sensitive to climate change. While global temperatures have risen by an average of 0.7° C due to anthropogenic warming, the Arctic has warmed 2.0-2.5° C.
"Those ships will be emitting black carbon pollution right near the glaciers and the sea ice where they can do the most damage," said David Marshall, senior council for the Clean Air Task Force, a nonprofit committed to air quality and climate issues. The Task Force helped support Corbett's work but Marshall did not work directly with the study's authors.
Marshall called the study "the most up-to-date survey of shipping emissions in the Arctic." He believes the research "can provide a firm foundation for policy makers trying to assess the impact of those emissions."
(Editor: Shipping is the lifeblood of commerce - without would cause a world crisis - ships should be allowed to use all available means to stay in business - shorter routes (thought the Arctic) means lower costs which means less pollution - ships must be allowed through the Arctic while this opportunity exists - the ice is not going to be gone forever.)
Posted by Voyage Adviser at 4:53 AM