Almost 50 institutional investors signed up to a 'climate risk action plan' at a summit in New York, which includes a promise to plough $10 billion into clean technology within two years. Signatories included Calvert, F&C Management and Al Gore's Generation Investment Management.

The institutions have also set a target to reduce energy use from their core real estate portfolios by 20% over three years, and incorporate green building standards into investment decisions as well as agreeing to a number of other initiatives, such as companies they invest in to report on the financial risks posed by climate change.