Have just two children to help cut CO2

Couples were today urged to have no more than two children to help reduce the environmental impact of the rising world population.

Doctors said with greenhouse gas emissions increasing, having a large family could be as damaging as driving a 4x4 or owning a patio heater.

Writing in the British Medical Journal the team, including John Guillebaud of University College London, said universal access to contraception was needed.

The article cites research by the Optimum Population Trust which said each birth in Britain will be responsible for 160 times more greenhouse gas emissions than a birth in Ethiopia.

It said: "By providing information and appropriate contraception, doctors should help bring family size into the arena of environmental ethics."

Family planning did not have to be coercive, as in China, the team added.