Pen-guano a climate change problem and solution

In a surprising discovery, it’s been found that ammonia released from the guano of the Antarctic’s millions of penguins may help buffer that continent’s heating due to climate change.

Researchers say they’ve found it adds to the formation of cloud-seeding aerosols!

Which means the decline in penguin populations could further accelerate climate change.

Penguins are only found in the Southern Hemisphere and forty million of these hardy birds live in and around Antarctica. Two species, the emperor and the Adélie, actually call the continent home, while others, such as the chinstrap, gentoo and macaroni, just use the Antarctic Peninsula for breeding.  As the British Antarctic Survey says: “ the real home of all penguins is the cooler waters of the Southern Hemisphere.”

These birds feed on protein-rich fish, squid and krill, that ends up as guano (penguin poo) once they come back onshore. Penguin rookeries can house a million or more breeding pairs. That’s a lot of guano, and a lot of nitrogen released once it all starts to break down.

The nitrogen, in the form of ammonia, is often experienced by humans as a pungent fishy smell downwind of a seabird colony.

In Antarctica, such ammonia may play a role in cloud formation, says Mathew Boyer, atmospheric scientist and Ph.D. student at the University of Helsinki.

Boyer and colleagues measured air ammonia concentrations on the Antarctica Peninsula, between January and March in 2023, near a colony of 60,000 Adelie penguins near Marimbio Base, an Argentine research station on Marambio Island.Ammonia concentrations, 8 km downwind of the colony, were greater than 13.5 parts per billion, more than 1,000 times higher than the baseline value, says Boyer.

Even when the penguins had left the rookery at the end of February, ammonia concentrations were 100 times higher than the baseline, as the guano left behind was still releasing gas. “I thought the ammonia would decrease more quickly when the penguins left the site, says Boyer.”

Concentrations of cloud-forming particles also increased sharply when the wind blew from the rookery, sometimes creating a, presumably pungent, fog over the study site

Boyer says that the ammonia’s reaction with the sulphur compound dimethyl sulphide (DMS), emitted by phytoplankton, produces aerosols. These plumes of particles act as surfaces on which moisture can condense, forming clouds. More clouds mean more sunlight is reflected, and heating reduced.

Marine phytoplankton DMS gives the sea its smell and is well known for its role in cloud formation.

“Penguins and phytoplankton have a synergistic role in the formation of particles in the atmosphere,” says Boyle.

Although gaseous ammonia doesn’t last long in the atmosphere, he says, hours to a day at most, the particles could last several days.

During that time, they could be transported over parts of the Southern Ocean and Antarctic continent, impacting cloud formation over a larger area, he says. This could be particularly important inland, where there’s not much in the way of other aerosols.

Antarctic sea ice loss is already threatening habitats, food sources and breeding behaviour of most penguin species, leading to population declines. Some species could be extinct by the end of the 21^st century, says Boyer, adding that such losses could cause further warming in the summer due to  reductions in cloud cover caused by lack of   aerosols.

This all makes Antarctic atmospheric science more complex. Fundamentally, Boyer says, the Antarctic atmosphere depends upon the interactions between sea ice, phytoplankton metabolism, and bird populations—all of which change in ways that are not well understood.

“There are connections between things that happen on our natural planet that we just don’t necessarily expect, Boyer told the Washington Post, “…and this is one of them.”

The paper was published in Nature Communications Earth and Environment.

Guano does the same thing elsewhere