A Peat Bog As Big As England, And A Rare Glimpse At Earth's History

Dr. Simon Lewis of the University of Leeds has discovered a vast peatland in a remote part of the Republic of Congo. The bog covers an area the size of England and is thought to contain billions of tons of peat. Scientists say that investigating the carbon-rich material could shed light on 10,000 years of environmental change in this little-studied region.

ROBERT SIEGEL, HOST:

Farther west in Africa, in Congo, Brazzaville, scientists have found a remarkable peat bog - a vast expanse of decaying plant material. The discovery could tell them about the whole planet's atmospheric history. It is a rare, tropical peat bog. It's the size of Pennsylvania. The thick layer of carbon it traps may offer clues to what was in the air over 10,000 years ago. Dr. Simon Lewis of the University of Leeds led the research team, and he joins us now to tell us about this little-studied region. Welcome to the program.

SIMON LEWIS: Thank you.

SIEGEL: I guess little-studied is an understatement. How could someplace so vast and unusual go undisturbed and unnoticed for so long?

LEWIS: Yeah, it's a surprise given this age of Google Maps and satellite monitoring. But the satellites can't really see through the vegetation and can't see underneath the water of this huge wetland area. So obviously, we knew that in this Central Congo region, over Congo, Brazzaville and the Democratic Republic of Congo, is the world's second-largest wetland in the tropics. But what we didn't know was whether this forest - growing under these waterlogged conditions - what was underneath it. So we discovered that actually, there is this layer of peat, up to seven meters deep, that is underneath both the forest and the water in this little-studied region.

SIEGEL: So what secrets about the Earth's history might be revealed by this huge peat bog?

LEWIS: Well, we've only just started the analyses, but the initial analyses show that the base of the peat is about 10,000 years old. So this has been forming very slowly for the last 10,000 years after the end of the last ice age when the world got warmer and that region got much wetter. Peat is partially decomposed plant matter so that's carbon-rich material. So the first thing we will be able to estimate is how many billions of tons of carbon are stored underground, underneath this swamp. And the second question we'll be able to answer is that as peat forms, it captures some of the environmental conditions of the time when it was formed.

So by analyzing cause of this peat, we'll be able to build up a picture of environmental change - particularly the environmental change and how wet that region was and how warm that region was over the last 10,000 years, which is particularly interesting in terms of the pre-industrial period. And then that, thirdly, will assist us in building much better predictive models about how that region will be impacted by human-induced climate change over the coming century.

SIEGEL: What does it look like? And what kind of creatures inhabit this area?

LEWIS: It looks like a wet, tropical forest, but the canopy is much shorter, the trees are much shorter 'cause it's a quite harsh climate for trees to grow in. And it's waterlogged for nine or ten months of the year, but it's good for those animals that are often hunted in other places. So they're very high density - some of the world's highest densities of lowland gorillas and quite a number of elephants living there, which you can see by their tracks.

SIEGEL: This is nature's own wildlife preserve. People just aren't there.

LEWIS: Yeah, it's really fantastic for wildlife. So long as it can be - continued to be protected. The animals are using that swamp for a few months of the year. But obviously, when the water gets very deep, then they are traveling north out of the swap to drier areas to spend the rainy season.

SIEGEL: Is this an area, by the way, that is in any way threatened by development or urbanization or even agriculture?

LEWIS: It's very sparsely populated. Its remoteness, I think, will protect it for, at least certainly for now, in the immediate future. Peat bogs in southeast Asia have been really decimated by use of those areas to grow palm oil. And obviously, those companies are starting to move to Africa.

SIEGEL: Dr. Lewis, given the size of this place that you've identified or discovered, is this going to be pretty much you're home away from home for the rest of your working life?

LEWIS: (Laughter) Well, I don't have all the specialist skills to be able to extract everything that scientists can do from these peat cores. So I'll be working with other scientists to extract as much information about the past climate and past vegetation history of there. And then, we'll be feeding that into people who model climate change to be able to feed this into future projections. So I think it's great because we're discovering all this raw material for a real, new window on the functioning of this remote part of the Central Congo base.

SIEGEL: Dr. Lewis, thank you for talking with us.

LEWIS: Thank you.

SIEGEL: That's Dr. Simon Lewis of the University of Leeds.

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