Conservationists haven’t always spoken the language of bankers or economists – but they are learning quickly. Debt, data, and models are increasingly providing a shared language for those who normally talk bonds and those whose language may focus on saving coral reefs.

I learned this from an EarthOptimism talk given by Mark Spalding, who works on oceans with the Nature Conservancy. Two decades ago, he helped map all the coral reefs in the earth’s oceans – the first time this had been done. That led, 10 years ago, to a collaborative project to map the ocean’s wealth which has found that the ocean may represent as much as $1.5 trillion to $3 trillion – or three to five per cent of global GDP.