Ammonia gas from bird feces sets off a reaction that may buffer local effects of climate change according to recentUniversity of Helsinki study

“Biological processes influence atmospheric composition and climate through a variety of mechanisms. For example, living organisms emit vapors that moderate cloud properties via the production of aerosol and cloud condensation nuclei (CCN) or ice nucleating particles (INP), which subsequently impact Earth’s surface radiative balance, precipitation, and weather. Changes in the biology of an ecosystem can therefore impact climate.”

 -- Penguin guano is an important source of climate-relevant aerosol particles in Antarctica, Matthew Boyer et al.

Penguins devouring a diet of fish and krill near Marambio Base, a research station on the Antarctic Peninsula (operated by Argentina) leave behind piles of foul-smelling guano (excrement) which is full of nitrogen waste. Scientists who measured ammonia levels in the air found that the concentration of ammonia was elevated when wind blew from the direction of a nearby Adélie penguin colony of 60,000 about five miles away, the ammonia concentration increased to as high as 13.5 parts per billion. That figure is over 1,000 times higher than the baseline value that is naturally found in Antarctica (less than 10.5 parts per trillion).

The ammonia enhanced the particle concentrations in the clouds up to 30 times than the background, according to Matthew Boyer, a PhD student studying aerosol processes in polar environments.

WATERTODAY reached out to Matthew Boyer, research lead to discover more Nature’s connections to the impacts of climate.

Interview with Matthew Boyer, Doctoral Researcher at the Institute for Atmospheric and Earth System Research, University of Helsinki, Finland

By Suzanne Forcese

WT: Matt tell us about your area of research and the journey that drew you to researching aerosols, Penguins, and climate change in Antarctica.

Boyer: I look at processes related to aerosol particles in the polar regions, and at the University of Helsinki, there is a lot of expertise on the process of new particle formation, which is the process when gases interact to form particles in the atmosphere.

We have a lot of specialized instrumentation that can measure the gases, as well as the chemistry of these gases when they start to form new particles, and subsequently the particles themselves.

We are interested in these processes in Antarctica, because it’s a remote location that is far away from anthropogenic pollution sources, meaning is virtually free of anthropogenic pollution.

There is also virtually no vegetation on the continent. Human activities and plants are key sources of gases and particles. So, the Antarctic atmosphere is quite pristine, and the background concentrations of aerosol particles are rather low in comparison to other regions in the mid-latitudes. Sources of atmospheric particles in this region are therefore interesting to us.

In general, atmospheric scientists are interested in these aerosol particles because they have an impact on the formation of clouds. Particles are necessary for cloud formation, and the concentration of particles present when a cloud forms has an impact on the properties of the cloud.

Clouds are also relevant for climate, as they affect radiation in the atmosphere. Therefore, the gases and particles that affect cloud formation can impact climate, and identifying key sources in Antarctica is relevant in this regard. I didn’t specifically choose to research penguins, but since they are present in the Antarctic environment and can impact the local atmosphere, they have become relevant for my research.

WT: As lead study author, your most recent paper was published (May 2025) in Communications earth & environment.

Please tell our viewers about the research project you led in January-March 2023. Our viewers would be interested in the details of the equipment you used, how it was set up, the challenges etc.

Boyer: We conducted a study on the Antarctic Peninsula during the Antarctic summer. Specifically, we were at Marambio Station, which is an Argentinian station. The island on which the station is located also has a penguin colony, meaning we were located close enough to measure their impact on the atmosphere downwind.

The study featured a lot of different instrumentations to characterize each step to connect gases to particles to cloud formation. These instruments included mass spectrometers; absorption spectrometers; instruments to measure the size, number, and chemistry of particles, chambers to quantify aerosol-cloud interaction processes, and an instrument to measure cloud droplets.

It’s rare to have collocated instruments that span all these processes, especially in Antarctica. I put a lot of time and energy into measuring ammonia, which is generally underrepresented in measurements, and particularly measurements sensitive and fast enough to quantify the impact of ammonia on new particle formation.

WT: Why was it important that your observations occurred at this time?

Boyer: Antarctic summer is the time of year when there is abundant sunlight. The sun has a few impacts on our study. First, there is enhanced microbiological activity in the ocean during the summer, and these organisms are sources of sulfur gases that are emitted by the ocean. Second, the sun is important for photochemistry and oxidation, which leads to chemical changes to gases in the atmosphere. These chemical changes to gases make them less volatile and more likely to condense, which is relevant for particle formation. Third, during this time of year, the penguin colony was present nearby our measurement site, and we could therefore measure their impact on the atmosphere.

WT: The penguins eat and do what comes naturally.

Boyer: And what they leave behind is a source of ammonia.

WT: Can you give us a 101 on ammonia please.

Boyer: Ammonia is a gas that enhances the process of new particle formation, which is the process of gas-to-particle formation. The other gases that contribute to this process originate from sulfur compounds emitted by phytoplankton in the ocean, namely dimethylsulfide (DMS) and its oxidation products. Ammonia enhances the rate in which aerosol particles form via this process and thus increases the number of particles. The new particle formation process doesn’t strictly need ammonia to proceed, but ammonia boosts the rate of the process considerably (up to 1000 times faster). Ammonia is notoriously difficult to measure, meaning that atmospheric measurements of ammonia, sensitive enough to resolve these processes, are high

WT: Why is this relevant in Antarctica?

Boyer: In general, the Antarctic atmosphere is a pristine environment. It’s located far away from human pollution sources, so it is virtually free from anthropogenic pollution, and there virtually no vegetation. The background aerosol particle concentrations are low as a result. New particle formation, occurring from gases emitted from natural sources (e.g., penguins and the ocean), is therefore an important source of aerosol particles in the region. We observed the enhancement of particle concentrations up to 30 times higher than the background after NPF events where ammonia had an enhancement effect.

 WT: Why does this matter for climate change?

Boyer: Aerosol particles are necessary for cloud formation; liquid water will not condense to form cloud droplets without the presence of aerosol particles.

Clouds influence the surface radiation budget, which affects surface temperature. Therefore, clouds impact climate change. This is true across the entire planet, not just in Antarctica.

Interestingly, the concentration of aerosol particles present when a cloud forms has an impact on the properties of the cloud and its climate impacts. Higher concentrations of aerosol particles lead to clouds that are more reflective with respect to solar radiation, for example.

In this context, the strength of local aerosol particle sources in Antarctica matters, as the particle concentration affects the climate impacts of the resulting clouds. This is especially true in clean environments, such as the Antarctic atmosphere, where particle concentrations are low and local sources are limited (as previously discussed). The strength/rate of particle formation processes is quite relevant in these conditions. Hence, the enhancement in particle formation from ammonia/amines has an impact.

WT: How did you demonstrate the link in these processes in your study?

Boyer: We have simultaneous measurements of each step between ammonia and clouds. For example, we measured the concentration of ammonia and other gases that participate in the particle formation process. We measured the chemical composition of the gases as they start to form particles, and we measured the number and size of particles that were formed from this process and tracked their continued growth to larger sizes. Then we had instrumentation capable of evaluating the cloud formation potential of these particles, as well as an instrument to tell us about the cloud droplets after they were formed in the atmosphere.

WT: Polar regions are experiencing dangerous levels of warming. Please comment on the penguins, the cloud cover and how everything works in synergy.

Boyer: In general, clouds have a net cooling impact on Earth’s climate, but it becomes more complicated over snow/ice surfaces. So, we can hypothesize that the clouds lead to a cooling effect in the region, which is also consistent with conclusions from a modelling study on similar processes in the Arctic region.

I want to stress that determining the magnitude and direction (cooling or warming) of climate impacts from clouds that form are outside the scope of the measurements reported in our study, but we can say that we observed evidence the penguins influence clouds, and these clouds will indeed impact the local climate in Antarctica. Quantifying the radiative impact of these clouds is an important next step for this research.

WT: Do the clouds cover more area than the penguin colony?

Boyer: Absolutely, the gases and particles influenced by the local penguin colony will cover more area than the penguin colony. Particles can persist in the atmosphere for up to 2 weeks, meaning some of these particles could be transported elsewhere and impact cloud formation far away from the penguin colony.

WT: Is it just penguins that are involved in the process of possibly mitigating the effects of climate change?

Boyer: Another key point here, is that other species of penguin, sea birds, and even seals are certainly also a source of ammonia, and colonies of these animals are located around the coast of Antarctica. The strength of our study is that we were located close to the colony described in the paper, such that we were able to measure the atmospheric processes occurring downstream. But we expect that these processes are relevant along the entire coast of Antarctica, given the distribution of these penguin/sea bird colonies.

WT: Is Antarctica the only place where this phenomenon occurs?

Boyer: There are also modelling studies from the Arctic region that suggest these processes could be impactful on the local climate in the North, too. There are also sources of ammonia that can impact particle formation and cloud processes in more temperate regions in the midlatitudes, but Antarctica is quite a unique environment because it quite pristine and located far away from other particles sources, such as anthropogenic pollution.

WT: Any final thoughts you would like to share with our viewers?

Boyer: I think our study demonstrates the deep connection between ecosystem and atmospheric processes, which are impactful on climate. As I mentioned before, the details of the cloud radiative properties are beyond the scope of our study, meaning we did not directly measure them to say how much cooling/warming potential these clouds have in Antarctica. So, we can only hypothesize about this impact from penguin. A follow up study to characterize the radiative properties of clouds is needed.

In general, I think this connection highlights that changes to the Antarctic environment, will impact the biology, which will intern impact the climate. It is known that biology-climate feedback exists for other living things, and this is just another example of this in an environment that we expect will change rapidly and subsequently impact local ecosystems (on land and in the ocean).

WT: Before we go, you are about to defend your doctoral thesis in the next week and WT wishes you all the best. We understand, according to the Doctoral Programme in Atmospheric Sciences that you have been educated as a top-level scientist with multidisciplinary skills to tackle the future challenges of climate change, air quality and environmental technologies.

What’s next for you personally?

Boyer: I am interested in continuing measurements related to aerosol particles and clouds, especially in the Arctic and Antarctica, where rapid changes are occurring in the local environments.