By Richard Black
Environment correspondent, BBC News website
Money invested in protecting nature can bring huge financial returns, according to a major investigation into the costs and benefits of the natural world.
It says money ploughed into protecting wetlands, coral reefs and forests can bring a hundredfold return on capital.
The Economics of Ecosystems and Biodiversity study (Teeb) is backed by the UN and countries including the UK.
The project's leader says governments should act on its findings at next month's UN climate summit.
Teeb is the first attempt to evaluate the economic value of "ecosystem services" - things that parts of the natural world do for free, such as purifying drinking water or protecting coasts from storms - on a systematic and global basis.
"We have now evaluated 1,100 studies ranging across different countries and different ecosystem services," said study leader Pavan Sukhdev, a Deutsche Bank economist.
"And we find that with protected areas, for example, no matter how you slice the figures up you come up with a ratio of benefits to costs that's between 25-to-one and 100-to-one.
"Now we can say quite confidently that there is a solid benefit from investing in protected areas," he told BBC News. …