In a new study, researchers from Dalhousie University and the University of Toronto have found that seabird droppings can affect cloud accumulation in the Arctic, effectively helping to cool the climate in the process, and help to decrease the Arctic melting rate.
The findings came as a surprise to the study’s authors who used computer modelling to simulate the effects of seabird guano -specifically, the copious amounts of ammonia released by the microbial breakdown of the bird poop- on cloud formation and the cooling of Arctic regions. The results showed that on its own, the extra cloud coverage originating from the bird droppings ends up reflecting as much as one watt per square metre of radiant heat from regions of the Arctic where seabird colonies are found.
“There is a connection between ecology and climate that certainly surprised me. The environment is very interconnected,” says Gregory Wentworth, formerly of the Department of Chemistry at U of T and now atmospheric scientist with Alberta Environment and Parks and co-author of the study, in conversation with the Christian Science Monitor. “How often do you hear about bird droppings being able to affect climate?”
Between the months of May and September, tens of millions of breeding seabirds such as terns, puffins and jaegers take up residence in the Arctic and near-Arctic regions north of the 50th parallel. Their uric acid-rich droppings are broken down by microbes, releasing an incredible 33,000 tonnes of ammonia, according to the researchers’ estimates, which combines to form the extra cloud coverage.
“Our chemical-transport model simulations indicate that the pan-Arctic seabird-influenced particles can grow by sulfuric acid and organic vapour condensation to diameters sufficiently large to promote pan-Arctic cloud-droplet formation in the clean Arctic summertime,” say the study’s authors, whose work is published in the journal Nature Communications.
Evidence has shown that climate change is increasing the Arctic melting rate and hitting the area faster and harder than other regions of the planet, a testament to the sensitivity of the Arctic’s climate system and the dramatic effects that changes in climate can have on ecosystems. A 2014 study by the U.S. National Oceanic and Atmospheric Administration found that Arctic air temperatures are rising at more than twice the rate of the rest of the world, a phenomenon dubbed Arctic amplification.
The seabird study shows once again the interplay between nature and climate in the planet’s polar regions, say the study’s authors, who point out that further warming in the Arctic may cause changes to bird populations and migration routes, which could in turn further impact the cooling capacity of Arctic regions.
“The findings are surprising, and support the precautionary principle; there are likely [other, similar] interconnections between the living and non-living components of Earth’s climate system that we don’t yet understand,” says Randall Martin, co-author of the study and head of the Atmospheric Composition Analysis Group at Dalhousie University.
A 2015 study from the University of British Columbia reported that since the 1950s seabird populations around the world have plummeted by almost 70 per cent. Researchers attribute the decline to a range of factors including human overfishing, oil and plastic pollution in the oceans as well as environmental changes brought on by global warming.