The report written by former World Bank chief economist Nicholas Stern said that failure to tackle climate change could push world temperatures up by 5 degrees Celsius (9 Fahrenheit) over the next century, causing severe floods and harsh droughts and uprooting many as 200 million people.


The study recommended taking action now to offset the far greater cost of dealing with climate change later.

But Barkindo told an energy conference in Moscow that the Organization of the Petroleum Exporting Countries (OPEC) -- which holds around two thirds of the world's oil reserves -- opposed such research efforts.