In an attempt to secure a new global deal to combat climate change, the world's richest nations have agreed to cut carbon emissions by 80% by 2050.
Leaders at the G8 Italy summit agreed for the first time to set a 2 degrees C limit on any human-induced global temperature rises - a level considered to be a danger threshold. The G8 move is designed to revitalise UN-led talks on a global "son of Kyoto" agreement, which reach a climax in Copenhagen in December.
Developing countries including China and India are being urged to cut their emissions by 50% over the same period. However, those nations want guaranteed subsidies to help meet the cost of converting their industries to low-carbon technology. They are also suspicious of signing up to the 2 degrees C warming threshold because it implicitly puts a cap on their growth.
Another potential stumbling block is that the G8's declaration left unclear the baseline on which the emissions cuts will be calculated, prompting critics to describe it as a fudge. Britain backs a 1990 start date, while the US favours a later one, meaning it would make a smaller reduction. However, it is hoped the G8's gesture will draw developing nations into serious negotiations.
However, environmental campaigners have criticised the G8 for failing to produce short-term targets for 2020, which scientists believe are essential to ensure the 2 degrees C threshold is not breached. Antonio Hill, speaking for Oxfam, commented, "The G8 might have agreed to avoid cooking the planet by more than 2 degrees C, but they made no attempt to turn down the heat any time soon. 2050 is too far off to matter - poor people are being hit today. We must see emissions cuts of at least 40% by 2020 and G8 money to help the poorest countries cope with climate chaos."
American officials have confided they cannot cut emissions as fast as the science requires, because the issue is still too politically contentious in the US Congress.
