Tuesday, April 28, 2015

Arctic Warming Feedback Loops: Algae Blooms and Thawing Permafrost

The Arctic is the epicenter of global warming and what happens in the far north has global implications. New research points to previously unknown warming feedback loops in the Arctic that could push us past irreversible tipping points. The latest research points to relationships between warming, algae blooms and carbon releases from the permafrost. Together these three phenomenon could significantly exacerbate global warming.

Average temperatures in the Arctic are already 2.7°F higher than the 1971-2000 average, according to some estimates that is warmer than it has been in as much as 44,000 years. While the entire earth is warming, Arctic temperatures have increased at almost twice the global rate and far exceed the bounds of historical natural variability.

Gifford Miller of the University of Colorado, is one of the many researchers who are studying Arctic warming. “Our findings add additional evidence to the growing consensus that anthropogenic emissions of greenhouse gases have now resulted in unprecedented recent summer warmth that is well outside the range of that attributable to natural climate variability,” Miller said.

This warming has both local and global implications. Locally, warmer temperatures are destroying a centuries old way of life by preventing Nunatsiavut Inuit communities from hunting fishing and trapping. This has led to a host of social problems from family strife to drug and alcohol abuse.

Globally the warming Arctic is disrupting weather patterns all around the world. The warming Arctic has caused the jet stream to be less stable and the result is that weather patterns stay longer in one place.

The National Oceanic and Atmospheric Administration (NOAA) 2014 Arctic report card paints a grim picture of rapid warming and a distressing prognosis for the future.

Scientists have discovered some unexpected corollaries of Arctic warming that could significantly worsen the climate picture. A new study published in PNAS uses computer models to suggest that algae blooms (aka phytoplankton) in the Arctic Ocean could accelerate warming by as much as 20 percent by the end of this century.

Phytoplankton thrives on the combination of thinning ice and elevated levels of atmospheric CO2. When the phytoplankton dies it carries the CO2 to the sea floor. While this has been considered to be a good way to remove carbon from the atmosphere, the authors of this study suggest that it may actually increase warming by trapping more heat in the upper layers of the ocean where it can easily be released back into the atmosphere.

"We believe that, given the inseparable connection of the Arctic and global climate, the positive feedback in Arctic warming triggered by phytoplankton and their biological heating is a crucial factor that must be taken into consideration when projecting future climate changes," says Jong-Seong Kug, a professor at POSTECH's School of Environmental Science and Engineering and one of the leaders of this study.

Algae blooms could cause summer temperatures in the Arctic to be as much as 23.4° F warmer in than they were before human emissions began in the 1800s. If the 20 percent increased warming figure proves to be correct that would increase temperatures to 28° F warmer. This risks thawing the permafrost which would release vast quantities of carbon. 

According to a University of Georgia study published in April ancient organic matter locked away in Arctic permafrost for thousands of years, is now being transformed into carbon dioxide and released into the atmosphere. While scientists have been aware of the dangers of carbon released from the melting permafrost, the findings from the University of Georgia Skidaway Institute of Oceanography, documents what happens when organic carbon is released.

Thawing permafrost causes bacteria to eat away at the previously frozen organic matter and this releases carbon dioxide. This is troubling because there is more than ten times the amount of carbon in the Arctic soil than has been put into the atmosphere by fossil fuels and 2.5 times more carbon is locked in the permafrost than exists in the atmosphere today.

The findings of this study show that 60 percent of the carbon in the thawed permafrost was converted to carbon dioxide in only two weeks.

While the Intergovernmental Panel on Climate Change (IPCC) project significant warming their models do not take Arctic algae or melting permafrost into account.

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