The G8 countries have re-iterated their target of reducing greenhouse gas emissions by 50% by 2050 but the so called G5 have said this should be more like an 80% reduction.

The G5 countries made up of Mexico, Brazil, China, India and South Africa challenged the Group of Eight countries to cut their greenhouse gas emissions by more than 80% by 2050. The joint statement from the G5 developing nations said: “It is essential that developed countries take the lead in achieving ambitious and absolute greenhouse gas emission reductions.”

Environmental organisations have also called the 50% target “pathetic” and said more needs to be done to tackle climate change. The five nations also urged developed countries to commit to an interim target of a 25-40% cut below 1990 levels by 2020.

South Africa said the G8 statement was a “regression”, criticising the lack of firm targets to achieve sufficient cuts in emissions.

The G8 also voiced concern about soaring oil and food prices, and Zimbabwe, and pledged to speed up aid to Africa. But climate change has been one of the stickiest issues tackled at the summit in Toyako, northern Japan.

The five-page communique by the G8 – Britain, Canada, France, Germany, Italy, Japan, Russia and the US – repeats last year’s “vision” to reach the target of cutting emissions by at least 50% by 2050.

The EU had wanted the G8 to confirm that the 50% cut would be measured from 1990 levels of CO2 – as agreed under the Kyoto climate protocol.

But when the question was raised in a press conference Japanese Prime Minister Yasuo Fukuda said the cuts would be measured from “current levels”.