Coral reefs could be condemned to extinction at next month’s Copenhagen climate summit, at an economic cost of nearly £600,000 per hectare in some areas, and a loss of livelihood for 500 million people. That was the warning given by Pavan Sukhdev at the Natural History Museum’s Annual Science Lecture last night, in his talk, The Value of Nature.
The future of coral reefs has reached a tipping point and the outcome of the Copenhagen Summit will have a big impact, according to Sukhdev.
Oceans are vulnerable to climate change because increasing levels of carbon dioxide can be dissolved in water, making the oceans more acidic.
At Copenhagen, governments are likely to talk about limiting carbon dioxide emissions so they only make up 450 parts per million (0.045%) of the atmosphere. But Sukhdev warns that this level is too high.
If levels of carbon dioxide in the atmosphere go above 350 parts per million (0.035%) then the oceans will become too acidic for corals to form, he declared.
‘Our representatives at Copenhagen are making a choice on our behalf either to have – or not to have – coral reefs,’ he announced. ‘If you do not agree with their choice then this is the time to let them know.’
Pavan Sukhdev, leader of the Green Economy Initiative for the United Nations Environment Programme, warned that even though natural resources and the services they provide appear to be free, they give great economic benefits. They can serve as a barrier against flooding, increase levels of nutrients in the soil, clean the air, secure water supplies and much more. By putting a financial value on these benefits, we avoid the danger of taking them for granted.
The cost to the world of not preserving ecosystems and biodiversity in general could be between £1.2 to £2.8 trillion a year, Sukhdev warned. That’s more than the cost of the recent recession - every year.
Sukhdev also emphasised the importance of forest ecosystems. Mature forests capture and trap carbon dioxide that would otherwise enter the atmosphere, contributing to global warming.
They also protect land from flooding, which is likely to increase as global warming intensifies, and they help to re-establish local water supplies.
Sukhdev estimates that replanting forests could increase agricultural productivity in surrounding areas by as much as 80% in some regions.
World leaders need to agree ways of protecting forests when they meet at the Climate Summit in Copenhagen next month.
One option is for developed countries to provide resources for preserving forests, and planting more of them, in less developed areas of the world. This initiative, called REDD and REDD PLUS, would help to offset carbon emissions.
Negotiations about carbon emissions targets themselves are proving difficult, but Sukhdev hopes for an agreement on preserving forests, as a positive outcome of the summit.
Sukhdev pointed out that we have an ethical choice to make about whether or not to preserve ecosystems. But if we choose to pass a death sentence on corals, and to endanger other ecosystems, then this will come at a massive economic cost.
Pavan Sukhdev is a senior banker at Deutsche Bank and is currently on secondment to the United Nations Environment Programme (UNEP) to lead the agency’s Green Economy Initiative, which includes The Economics of Ecosystems and Biodiversity study (TEEB), the Green Economy Report and the Green Jobs report.
Two big coral extinctions have taken place in the past 25 million years, when many species of coral died out. Museum scientist Ken Johnson studies these extinctions to find out what they can tell us about the way coral reefs will respond to climate change today.
Find out more about his work and the effects of climate change on the oceans.Extinction of coral reefs