By David Webb (MA ’22)

In 2009, geologist Barbara Sherwood Lollar of the University of Toronto discovered 1.6 billion-year-old water in a Canadian mine 2.4 kilometers below the Earth’s surface, the oldest found on the planet.

A breakthrough for earth sciences, astrobiology, and the search for the origin of life, Dr. Sherwood Lollar later chaired the NASA astrobiology strategy for the search for life in the universe, in partnership with the National Academies of Sciences, Engineering, and Medicine.

Dr. Sherwood Lollar was awarded the Gerhard Herzberg Canada Gold Medal for Science and Engineering in 2019, the country’s top prize for science and engineering research, as well as the John C. Polanyi Award by the Natural Sciences and Engineering Research Council. She is a Fellow of the Royal Society of the United Kingdom and the Royal Society of Canada.

I spoke to Dr. Sherwood Lollar in her home in Toronto via video call. 

My most important question: what would happen if I drank billion-year-old water?

You would probably sputter in a big way because it’s three times saltier than seawater. It’s not something you want to drink. It’s got a funky smell to it, largely because of dissolved sulfur compounds. It would make eating a rotten egg look good.

Would it poison you?

No. 

What is billion-year-old water and what has it taught us about the Earth today?

Groundwater is much more than just H2O. Every bit of groundwater has got things dissolved in it. It’s a bit like a train moving through a station — as it moves through the station, it picks up more and more and more passengers.

We measure the gases that get picked up in groundwater over time as it sits deep underground, what we call the subsurface, to get a sense of how long the water’s been there.

The water contains remnants of the atmosphere and ocean water at the time, and some remnants of other fluids that have mixed in at long timescales. The net total is more than a billion years in age.

What does a breakthrough look like for what we can find in such ancient waters? Is it something about the origins of life or old water systems?

This is the first time that we’ve actually found evidence of ancient components in something that is wet, that allow us to look at an ancient period of life before 2.5 billion years [ago] in Earth history, the Archean.

Before 2.5 billion years is a massive divide on our planet because we have an atmosphere that is largely deprived of oxygen. So any time we can get samples that tell us about the world before 2.5 billion [years ago], it’s pretty exciting.

As someone who lives in these unbelievable timescales on a daily basis, do you find that your approach is a bit different than colleagues in other fields?

I think if you ask that question of any geologist, yes, we do see everything through that lens of deep time. It’s part of what sucks you into geology, understanding the dynamic changes in our planet on a huge timescale.

But it also makes you really sober because it gives you a sense of rate. You will get climate change deniers, as we know, who will make a big deal out of the fact that, in the past, the Earth got much hotter than it is now, and much colder than it is now.

Well, yes it did. Two important points. One, modern society would not have survived that very well, if at all. Two, the rates of change are the critical aspect right now. 

The rates at which the planet is warming is unprecedented. And so it also gives earth scientists a very strong sense that the need for action has to be robust and quick, because the rates at which these things are happening are faster even than the very conservative estimates made by the [Intergovernmental Panel on Climate Change] already.

One of the themes in the new film Don’t Look Up is that the moment you declare, if we don’t do this, we’re all going to die, no one listens to you anymore.

If I’m talking to a friend or a colleague who is quite conservative and worried about the effect on business, I say to them, “Oh, you obviously don’t do business in the North. The permafrost is melting.”

Everything has to go into the North in the winter. In the summer, things are too difficult to transport. So it’s ice roads that get things in. It’s too expensive to fly stuff in. With the warming climate, our winter transport season has shrunk by three or four weeks on either end.

Talk to a diamond mining company about climate change. Oil and gas, mining, transport. This is already having a massive economic impact on their bottom line. They’ll tell you about climate change. 

I want to talk about Mars for a second. Your work has involved bacteria deriving energy from hydrogen kilometers underground, which is now being applied to investigations of past life on Mars. What amount of time do you spend thinking about other planets?

Around the time that life developed on Earth, if you were coming in and looking at our solar system, and comparing Earth and Mars, you might actually have looked at Mars and thought, “Oh, that looks either just as good as Earth or better.” Because we know now it had a warmer, wetter climate, it had a denser atmosphere than it does today.

The consensus is, if there is liquid water on Mars now, it would be in the subsurface. Within fractures in rocks, very similar to the ones we work on on Earth. A much more likely place for preservation of any existing life or signatures of past life that might have been on Mars is in the subsurface. 

Who are your role models and who should the role models of the future be?

Well, my personal role model is Ursula Franklin, an outstanding engineer and material scientist, but also an extraordinarily devoted advocate for peace and justice and compassion. [Renowned Canadian scientist Ursula Franklin taught at the University of Toronto for 40 years in physics and metallurgy. She wrote extensively on topics of pacifism, technology, feminism, social justice, and learning.]

She is someone who I look to when I go back and read and think about what she thought, and think about how she dealt with questions. She was a firm believer in the need to question. There’s a font of wisdom there that I still continue to turn to. 

Your work with ancient water deep in the subsurface is challenging prevailing theories for how life originated on Earth. How did the first cell start beating?

There are people who are looking at the actual mechanisms of the origins of life, and then there’s the question of where. What you’re referring to is the location.

Darwin originally talked about a small little pond on the surface. My colleague Tullis Onstott at Princeton, who is recently deceased, used to say, rather than thinking about Darwin’s warm little pond, maybe we should be thinking about a warm little fracture.

There are some really exciting questions about the variety of different ways that life can actually survive, even if photosynthesis never developed. Radioactive activity in deep fluids can produce hydrogen, and microorganisms love hydrogen. I call it the jelly doughnut of the microbial world. If it’s hydrogen, they’re going to eat it. And that’s a recipe that could take place on other planets and moons.

Around the time life evolved, the surface of our planet was a tough place. We were still having a lot of bombardment — that may have, as you referred to, brought in materials that could have contributed to the origin of life. But it also could have very quickly squashed any life that could have started to develop. So, one of the arguments is that if life had actually arisen in the subsurface, it would have had more protection from the surface.

To quote the famous Jurassic Park scientist, “Life finds a way.” There’s actually a fair bit of wisdom in that.

David Webb (MA ’22) is a fund manager of a climate and green technology impact fund. He is completing a master's at the Climate School at Columbia University.