Why we need to put a number on our natural resources

ECONOMISTS at the mighty International Monetary Fund used to joke that the institution's acronym should actually stand for "It's Mostly Fiscal". No wonder: the IMF is (in)famous for fretting about countries' budget plans, tax policies, growth strategies and capital flows.

Last week, however, the IMF's managing director Kristalina Georgieva discussed how some of its employees have branched into an unlikely pastime: whale-watching. "We have economists studying whales," she told a panel organised by the Paulson Institute, a foundation created by Henry Paulson, former US treasury secretary and Goldman Sachs luminary, that often champions environmental causes.

One of these economists is Ralph Chami, an IMF official who has studied how whales sequester CO2, removing it from the atmosphere, as part of an IMF analysis of the value of natural capital - the world's stock of natural resources.