How Bird Poop Could Help Keep the Arctic Cool
Researchers have discovered that ammonia produced from tons of seabird guano helps form low lying clouds that can partially block sunlight
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The fight against climate change has led to some strange discoveries: researchers recently found that feeding cows seaweed could reduce the methane content of their burps, others have suggested that dumping iron into the ocean may superpower carbon dioxide-munching phytoplankton, and still others are experimenting with injecting carbon into the ground to turn it into stone.
Now, researchers are turning to bird poop. A new study, published in the journal Nature Communications, suggests that excrement from our feathered friends has the power to cool the Arctic, reports Jennifer Viegas at Discovery News.
The new study, led by Betty Croft of Dalhousie University, focuses on how ammonia created from seabird poop affects the atmospheric chemistry of the Arctic by spurring the formation of clouds that can keep the region cool.
“There is a connection between ecology and climate that certainly surprised me. The environment is very interconnected,” study author Gregory Wentworth tells Eva Botkin-Kowacki at The Christian Science Monitor. “How often do you hear about bird droppings being able to affect climate?”
Fish is full of nitrogen, writes Viegas. And this delicious seafood treat is a favorite of colony-nesting seabirds like terns, puffins, murres and kittiwakes. After digestion, the seabirds squirt out lots of guano, which is full of uric acid produced from that nitrogen. The guano is then broken down by microbes, which releases ammonia, into the atmosphere. It combines with sulfuric acid and water vapor, forming particles which eventually collect water vapor and glom together, creating clouds.
“The cooling effects occur when the clouds are reflecting sunlight back into space,” Wentworth tells Viegas. “This effect is largest for clouds over darker surfaces, such as the open ocean, and is relatively minor over bright surfaces like sea ice and snow.”
The researchers were tipped off to the ammonia-guano connection during a trip the Canadian Arctic two years ago when air samples showed high amounts of ammonia during the times when the temperature was above freezing, according to a press release. The Arctic does not have the large concentrations of agriculture or industry that usually produces so much ammonia. So they looked around and soon tracked the source to the birds.
It seems impossible that seabirds could generate enough poop to create actual clouds. But hoards of birds flock to the arctic every year, reports Botkin-Kowacki, leaving behind an estimated 33,000 tons of ammonia. The researchers modeled the influence of this smelly compound in the generation of low-lying clouds. They found that this type of cloud cover could block about one watt per square meter of heat during warmer months.
“The research is important because it shows yet another way in which the biosphere is controlling aerosols and climate. This information is vital in order to more accurately determine how human activities have altered aerosols,” Ken Carslaw, director of the Institute for Climate and Atmospheric Science at the University of Leeds, tells Viegas.
While spreading more guano across the Arctic would do little to stop climate change, it is sobering to point out that in the last 50 years, researchers estimate that seabird populations have plummeted by nearly 70 percent worldwide.
Though more work is necessary to confirm this study's findings, reports Botkin-Kowacki, this study further demonstrates the amazing complexities of the biosphere.