Nov. 25 (Bloomberg) -- Brazilian and Mexican lawmakers backed a proposal to impose greenhouse-gas limits on some developing countries after 2020 as long as the richest nations first curb their output of emissions blamed for global warming.

The plan represents a departure from the traditional negotiating stance of most poor nations to reject any binding targets. The proposal was formed during a meeting of legislators from North and South American countries in Mexico City to address ways to stem carbon-dioxide emissions that contribute to climate change.

The group, known as Globe, aimed to boost communication between rich and poor nations ahead of United Nations-sponsored climate talks starting Dec. 1 in Poznan, Poland. The new proposal, which is not binding on their governments, hinges on developed countries acting first.

“The most advanced developing countries should aim to reduce the rate of increase of their own greenhouse-gas emissions between now and 2020, with a view to taking on binding absolute emissions reductions thereafter,” the Globe Americas Legislators Forum said in a statement posted on the Web site of Carbon International, a London-based consultant.

Any agreement must require that industrialized countries “deliver on their commitments” to trim emissions, and aid the transfer of technology that reduces CO2 emissions, the note said.

Globe, a London-based group of lawmakers founded in 1989 to protect the climate and provide energy security, didn’t immediately provide a list of nations that backed the proposal.

‘Reduce Intensity’

“In the period up to 2020, major developing countries should take on nationally appropriate commitments that reduce the carbon intensity of their development,” supported by richer nations, the lawmakers agreed. Carbon International provides communications services for Globe.

Developed nations need to slash their production of greenhouse gases at least 25 percent by 2020, compared with 1990 levels, according to Globe, a target that matches proposals to the UN from at least 36 countries, including European Union members and China.

An alternative, supported by at least 49 poorer nations, advocates more lenient reductions, of least 10 percent, by 2020, the United Nations Framework Convention on Climate Change said last week on its Web site. That document summarizes proposals for the two weeks of talks beginning next month.

The U.S. opposed inclusion of targets last year in an agreement drafted in Bali, Indonesia, to guide two years of international climate talks that are scheduled to end with a global deal in Copenhagen late next year.

To contact the reporter on this story: Mathew Carr in London at m.carr@bloomberg.net

Last Updated: November 25, 2008 11:01 EST