Most carbon reduction policies aim to do the job by increments. But these will not stabilise levels of atmospheric carbon dioxide — only slow the rate of increase.

In this Science article, Wallace Broecker of the US-based Lamont-Doherty Earth Observatory in New York suggests an alternative: a 'carbon pie' to be shared globally.

To fix the pie's size, an upper limit will need to be set on the increase of atmospheric carbon dioxide. Then, a country's population should be used to determine the size of their slice.

With this system, the world's developed countries get just a fifth of the pie. That means if the limit were 560 parts per million, their share would be 150 gigatons of carbon — an allowance they would consume in 25 years at current fossil fuel consumption rates.

Faced with this, developed countries would have to reduce emissions, while developing countries could sell bites of their slice off and still have enough to industrialise.

Broecker admits that agreeing on such an approach would be difficult in today's political climate, but insists that such measures are necessary.

Link to full article in Science

Reference: Science, 315, 1371 (2007)