Science Interviews

Interview

Fri, 11th Mar 2011

Is Blue Carbon the new Green?

John Bruno, University of North Carolina, Chapel Hill

Part of the show Trading the Oceans

Sarah - Buying and selling things we find in the oceans isn’t all about food and jewelry, and it doesn’t necessarily have to be a bad thing for marine life. Finding value in marine species and ecosystems can sometimes help to create incentives to protect them.

Around the world, efforts are underway to protect vital habitats that fringe the edges of the oceans – mangroves, wetlands, seagrasses and so on – by capitalizing on their ability to lock up carbon. We’re getting used to the idea of trading forests for their carbon, but now there are hopes for an emerging market in blue carbon.

To find out more Helen chatted with John Bruno, from the University of North Carolina at Chapel Hill.

John – Blue Carbon is what scientists call coastal vegetation including mangroves, salt Seagrass bedmarsh grasses, and seagrasses. And all three types of coastal vegetation are wonderful at sequestering carbon dioxide, so that is pulling carbon dioxide out of the atmosphere, simply through photosynthesis, they turn it into organic carbon, and they essentially move it down into their roots.

Unlike terrestrial plants these types of communities accrete vertically so they grow up vertically, sometimes at really high rates, like a cm or so a year. And so as they grow vertically they just store more and more carbon dioxide that’s been transformed into organic carbon below them. And they can do that for centuries or even much, much longer. And because they’re in salt water that carbon is not exposed to air so it doesn’t get broken down by bacteria and respired back into the atmosphere.

Both conserving blue carbon habitats and also restoring and replanting them is one of the really low hanging fruits as a solution towards mitigating the impacts of climate change.

And the wonderful thing is it has all these add on benefits. All three habitats serve as really important nurseries for all kinds of fish that are caught commercially in fisheries. They’re wonderful in protecting coastlines from erosion, so they’ll actually mitigate the effects of climate change such as sea level rise and increased intensity of storms. And they can create jobs for people just by enhancing fisheries production, so it’s really a win-win situation.

So there’s several groups all around the world that are trying to figure out how to fund the conservation and restoration of blue carbon through carbon trading markets and other activities and mechanisms.

Helen – Because these habitats are already in quite big trouble, aren’t they? We’re loosing them at a really astonishing rate?

Salt MarshJohn – Yeah, so the estimates are somewhere between 1-5% per year for each of these habitat types, and that’s substantially higher, probably 2-4 times higher than we’re loosing tropical rainforest at. So we’re loosing them really quickly and in the case of mangroves it’s primarily due to clearing for shrimp farms primarily but in some cases other types of development, putting up condominiums, or resort areas.

For seagrass, the main driver of loss seems to be water quality. So, sediment pollution, sedimentation from terrestrial development and also eutrophication, so the pollution by nutrients seems to be killing off seagrasses.

Salt marshes it’s really again about land development, people putting up sea walls in front of the marsh to protect their property, or marshes being wiped out for development.

Helen – They suffer a bit from a charisma gap don’t they, these habitats. We don’t really hear much about them and yet they’re really important. Are they as important as rainforests in terms of how much carbon they can lock away or other sources of carbon sinks?

John – They’re almost as important as rainforests in terms of the actual rate of sequestering carbon. So, of course there’s many times more area coverage of rainforest on the planet, but these blue carbon habitats sequester carbon about a hundred times faster than rainforest or other types of forest do.

So in terms of playing that role, it’s about a one to one, so both types of habitat play the same role. But you can conserve or restore one one hundredth of the area of a blue carbon habitat and get the same result in terms of carbon sequestration and storage.

Helen – And where would you say we are at with blue carbon right now? Is this Red Mangrovesomething that we’re going to really need to work hard at? Or are we already catching onto this idea?

John – I think at least in the scientific community and the NGO kind of development, conservation community, there’s been much more awareness of it just in the last six or eight months. So the UNEP released a really fantastic report just before the Copenhagen conference and there are several working groups being put together by Conservation International and the UN and a couple of other groups. So there seems to be headway going on.

As far as I know there’s actually no projects being funded by any of the carbon offset markets and that’s one of the really tricky things is that the markets aren’t really designed for this kind of project. Most carbon offsetting occurs through things like wind and solar power, methane recapture through landfills, and frankly primarily through Chinese hydroelectric projects. So the market is really geared towards those kind of projects, so there’s a lot of work going on trying to figure out really how to incorporate the blue carbon into that regulatory marketplace.

Sarah - That was John Bruno from the University of North Carolina at Chapel Hill giving us the low down on Blue Carbon.

And it’s going to be really interesting to see how this idea develops. Since we spoke to John, he’s been working on some pilot Blue Carbon projects in Ecuador helping shrimp farmers to replant areas of mangrove that were cut down to make way for their farms – and hopefully replanting will be something the farmers can make money from.

And just a few weeks ago, a group of leading conservationists and scientists held a meeting in Paris to discuss Blue Carbon and figure a way of taking it forwards. So I’m sure this is something we’ll come back to here on Naked Oceans.

Find out more 

Blue Carbon Portal

The Blue Carbon Project

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