From Svalbard, Norway to Greenland, Arwyn Edwards has tackled the extreme cold while conducting field research in glacier ecology. A senior lecturer in biosciences at Aberystwyth University in Wales, Edwards studies some of the smallest inhabitants of glaciers: microbes. His research focuses on microbial interactions with the cryosphere and how they are shaped by environmental change, especially areas where glaciers are melting rapidly.
After completing his Ph.D. in microbiology at Aberystwyth, Edwards continued to explore the immense microbial biodiversity found within glaciers. One focus of his research is cryoconite holes, complex glacial ecosystems that accelerate warming and glacier melt. As Marco Tedesco, a climate scientist at Lamont-Doherty Earth Observatory, which is part of the Columbia Climate School, previously explained, a cryoconite is a “pocket of soot, dust, algae and bacteria that drills into the surface. Given their dark nature, they absorb more solar radiation and, therefore, enhance melting.”
In an interview with GlacierHub, Edwards discussed past research projects and expeditions and described how climate change is impacting his field.
This interview has been edited for clarity and concision.
What sparked your interest in glacier ecology?
Originally, I trained as a microbiologist. I was curious about life in the Arctic, how microbial ecosystems form in extreme conditions, and what we could learn from those ecosystems. When conditions are tough, only a few organisms can tolerate them. So you see very simplified ecosystems compared with what you might have in a tropical rainforest or in agricultural fields if you’re looking at soil microbes. The Arctic seemed like a good place to try and look at ecology, but simplified. That was in 2006 during my Ph.D., where I went to Svalbard for the first time and did some sampling. I loved it. I’ve built my research career from there.
You have conducted a wide variety of field work and research. Which are you most proud of?
I’m most proud of a paper we published in 2016 that looked into the phenomenon of cryoconite holes. That’s been the major focus of my research for the last 20 years.
Cryoconite ecosystems are where you have dust on the ice surface, which then becomes colonized by microbes that can photosynthesize like cyanobacteria. As the cyanobacterial cells die, their chlorophyll breaks down and becomes brown in color, which reduces the albedo [the fraction of sunlight reflected] of the ice surface. The ice surface then melts and forms little potholes.
One member of my team used a spoon to gather cryoconites from multiple holes and put them into a study hole. For a number of holes, he overloaded them with cryoconite and watched how the shape of the hole changed. Tying that in with DNA analysis and biochemical analysis, we could eavesdrop on what the microbes were saying to each other in chemical terms: ‘Wow, it’s suddenly gone dark in here. We need to grow out from each other and adapt to the low light conditions.’
We realized that the microbes have really intricate responses to changes in their environment, and they are most comfortable when they’re spread out and have space to grow. The complex network of life interactions under such extreme conditions makes for a very productive ecosystem. That’s probably my favorite paper out of the nearly 70 glacier-related papers I’ve published.
“If we wake up the microbes in the Arctic, then it changes the Arctic’s response to climate change, and that has consequences for us all.”
How do these cryoconite holes reduce the albedo of glaciers, and what is the argument for conserving them despite their negative impact on the climate?
Glacier ice has a moderately high albedo, but if you start to put anything darker than the ice on the surface, it reduces the albedo and will absorb solar energy. And if you add a thin layer of dark debris, the reduction in albedo means that the solar energy that’s been absorbed is efficiently transmitted to the underlying ice. So cryoconite holes drive glacier melt quite rapidly.
But I don’t think removing all the cryoconites would be wise for several reasons. These are extremely intricate microbial habitats home to thousands of species of microbes—we know very little about the total biodiversity. Some of those microbes are also making things that could be economically important to us, like new antibiotics or enzymes.
Ultimately, my generation of researchers and perhaps my students’ generation of researchers are the last generations of humans that will be able to access this diversity of life on glaciers, because the glaciers are going away across Earth at an unprecedented and scary rate. So unless we conserve these habitats now, future generations of humans and future generations of scientists aren’t going to be able to do this research.
In 2016, you led the first polar night exploration of glacier ecology. What was that experience like?
That was phenomenal. In November 2016, we did our first polar night work. We went to a place on Svalbard that we’re very familiar with, and we were completely lost. So I then wondered how you would work in polar light on a glacier safely and efficiently? And I came up with some tips and tricks for it.
Next, I wrote a research proposal to the Royal Geographical Society, and I became the first arctic and mountain research fellow in the society’s 200-year history. We called the project ‘In the Bleakest Midwinter.’ We went back to Svalbard to do sampling in polar light. We were able to get cryoconite material and analyze its biodiversity to see how it changed over time.
That spawned a larger project called Cryo 365. I’ve been leading this project on Svalbard for a couple of years now looking at different seasons. The punchline is that things are alive in the winter. Even though it might be 24-hour darkness and very cold and snowy, things are still alive underneath that.
Currently, Svalbard’s climate is warming at a rate seven times faster than the global average. Has this rapid change affected field research?
It’s made everything we do really urgent. It’s urgent because we continue to need to develop clear evidence around climate impacts in the hope of convincing policymakers that we’ve got to mitigate climate change sooner rather than later. We’re running out of opportunities to collect samples to understand the environment, and it’s also becoming unpredictable and potentially more dangerous due to increased polar bear interactions and rapid glacier melt.
I don’t think that we will ever generate enough evidence to convince everybody, but we must keep trying.
What is the main takeaway readers should have about the link between climate change and glacier ecology?
My strong message is that microbes are sentinels. In any kind of ecosystem, they’re the first to respond to a change in conditions compared with polar bears or reindeer. But they are also amplifiers of climate change. They’re first responders, but they also turn the dial up.
That can happen in a number of ways. It can happen through the albedo reduction effect I spoke about earlier or through releasing greenhouse gases such as carbon dioxide and methane. If you wake up the microbes earlier and you give them fresh carbon sources to consume, they’re good at producing more greenhouse gases. So my take-home message would be: If we wake up the microbes in the Arctic, then it changes the Arctic’s response to climate change, and that has consequences for us all.
