Kobe: Environment ministers from the G8 rich nations on Monday urged leaders to set a global target to halve greenhouse gas emissions by 2050.

About 190 nations have agreed to negotiate by the end of 2009 a successor treaty to the Kyoto Protocol.

The Kyoto deal binds 37 nations to cut gas emissions by an average of 5 per cent below 1990 levels by 2008 to 2012.

A wide gap still exists in the G8 between rich and poorer nations over how to share the burden for fighting the climate change.

"To halve emissions, advanced countries should exercise leadership to achieve major cuts," Japanese Environment Minister Ichiro Kamoshita told a news conference.

The G8 ministers also stressed the need for funds to help developing countries adapt to climate change and limit their emissions.