Source: SciDev.Net Conference Service
21 December 2011 | EN
Mangroves store significant amounts of carbon
'Blue carbon' is seen as an increasingly important issue, but it needs to be backed up by better science, reports Mićo Tatalović.
Oceans are one of the least studied areas of the global environment and although 'blue carbon' — carbon dioxide stored in the oceans — is an emerging issue, if oceans are to make an impact at next year's UN Conference on Sustainable Development (Rio+20) as part of a global push for a Green Economy, more science is needed.
"Oceans is an obvious focal area for Rio," Peter Gilruth, director of the UN Environment Programme's (UNEP) early warning and assessment division, told SciDev.Net at the Eye on Earth Summit in Abu Dhabi (12-15 December 2011). "But data systems are not always there," he added.
"You may have data systems that are strong on the fisheries side but you might not have as much information on the changes in acidity or the effects of plastics in the food chain."
Oceans have many functions. They are the largest long-term carbon sink, with 90 per cent of carbon dioxide recycled though them. Three coastal ecosystems — mangroves, salt marshes and sea-grass beds — play a particularly important role in carbon storage, and they also help provide food security and protect coastal communities from tsunamis and floods.
Experts say that, metre for metre, coastal ecosystems are often more efficient at sequestering carbon than many tropical forests, and unlike many terrestrial systems, they continue removing carbon from the atmosphere and oceans for centuries. The soil below seagrasses, salt marshes and mangroves can hold 2-15 times the amount of carbon in comparable tropical forest soils, according to a paper prepared for the Abu Dhabi meeting.
Rolph Payet, special advisor to the president of Seychelles and president of the University of Seychelles, said, "blue carbon … will hopefully help to stimulate a lot of research.
"There is a lot of debate on which systems sequester the most carbon, or which release the most carbon. There is a lot biochemistry and geochemistry involved. And there's a lot of science lacking: a lot of areas are unknown, a lot of chemical processes are unknown, a lot of animal trophic structures are still not understood."
Robust case studies
Carl Gustaf Lundin, director of the global marine and polar programme at the International Union for Conservation of Nature, made a similar point in Abu Dhabi. About one-third of the carbon dioxide that humans had emitted was in the oceans but we knew almost nothing about it, he said.
"People don't talk about it, there's been very little policy focus on it and that's what we're trying to address with the whole blue carbon question," he said.
"Science has to be stronger, more convincing," agreed Louisa Wood, head of the marine assessment and decision support programme at UNEP's World Conservation Monitoring Centre, in Cambridge, United Kingdom. "We don't really have enough robust case studies yet of [blue carbon]," she told SciDev.Net. "Because the science is emerging, the data are also largely missing."
Although there is some local data on carbon sequestration rates of some seagrass, salt marsh and mangroves ecosystems, a global overview is lacking.
An overview is important if the blue economy, of which blue carbon is a part, is to be a key component of the green economy that will be high on the agenda of Rio+20. For now, scientific information is lagging far behind other sectors of the green economy and behind carbon locked in land forests.
"What we want to do is to put the oceans on the balance sheet. We have only an estimation of what carbon storage is conducted by the oceans, and it is just an estimate," Sylvia Earle, oceanographer and founder of the US National Geographic Society, told SciDev.Net.
Protect now, study later
Yet while supporting the need for research, Pacific island delegates from the Cook Islands, Kiribati, Samoa and Seychelles in Abu Dhabi stressed the urgency of preserving ocean ecosystems. Faced with a lack of data about ocean protection, the best action was to preserve now and study later, they told SciDev.Net.
And in his message to the conference, Kiribati president Beretitenti Anote Tong gave a reminder that even where data and information existed, it still had to be accessed and distributed in ways that could lead to practical policies and programmes.
"The lack or non-existence of environmental information ... is due not to the lack of data but fundamentally because of the lack of capacity in these countries to collect, process and convert this data into usable and relevant information and in a format that is useful for decision-making," he said. "This is the heart of the problem, and this is where partnership plays a key role."
This urgent need to improve and use knowledge of blue carbon and the oceans in general was why the topic was made one of nine 'special initiatives' discussed in working groups at the Abu Dhabi meeting, and was one of four initiatives selected alongside the meeting's final declaration to feed into the negotiations for Rio+20 in June 2012. The other topics were biodiversity, water, and network of networks.
The focus of the blue carbon special initiative is on seagrasses, salt marshes and mangroves, the three ecosystems that together may account for 70 per cent of ocean carbon sequestration capacity.
"There's a big focus at the moment on developing the science to justify the case for using carbon storage sequestration and storage as a means to justify conservation of those areas as well as potential set-up of carbon credits for payment for ecosystem services," said Wood.
Thabit Al Abdessalaam of the Environment Agency – Abu Dhabi said in his report to the conference on the oceans and blue carbon special initiative that the challenges were not just to improve the data gathered but to "deal with the data using the technologies we currently have".
For example, he said, there was a need for dynamic habitat mapping. "We need to come up with a measure of the oceans' capacity to ensure these [ocean based] services continue."
That is vital, because the threats to the oceans are diverse and growing. A recent UN report, 'Oceans at Rio+20' said at least 40 per cent of the global oceans were "heavily affected" by human activities and that 60 per cent of the world's major marine ecosystems had been degraded or were being used unsustainably.
The Eye on Earth special initiative, said Wood, would give impetus to looking at how different initiatives fitted together and to identify common gaps.
"It's been important to bring everyone together and then collectively look at what we're doing and what's missing," she said.
"It is implicit that any data collected would be made available — that goes without saying, but there are really big gaps. There are local datasets on the national and provincial level: there has been some mapping of these ecosystems, but they haven't necessarily been mapped in a consistent way and they haven't been brought together."
This article is part of SciDev.Net Conference Service's coverage for Eye on Earth Summit 2011
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