LONDON: A gulf needs to be bridged if the world is to sign a new climate treaty by a December deadline, according to proposals from more than 30 countries posted on a UN website on Tuesday.

The first suggested texts for a new pact underlined a rich-poor split on sharing the cost of fighting climate change, which has hampered ongoing UN-led climate talks meant to agree a deal in Copenhagen at the end of the year.

Rich countries agree they have to lead a climate fight after enjoying two centuries of industrialization, spewing billions of tonnes of greenhouse gases into the air.

They differ with developing nations on how much of the burden they should carry.

In proposals dated April and posted this week Canada said all countries should commit to concrete, 2020 emissions' limits.

Japan recommended unspecified emissions' targets per unit of economic output for big developing nations "with a view to limiting substantially their greenhouse gas emission growth".

That contrasted with the view of developing nations such as India.

"Developing countries may, on a voluntary basis, propose mitigation actions ... provided full costs are met by developed countries," read India's text.

Developing country submissions focused on rich nation funding of the fight against climate change. India, China and other developing countries said the rich should spend 0.5-1 percent of their national income (GDP).

China rejected discussion of long-term goals until rich countries as a group committed to cut their greenhouse gases by at least 40 percent below 1990 levels by 2020 -- referring to the top end of the most commonly referenced range of cuts.

Chief US negotiator Todd Stern said in March that insisting on a 25-40 percent range for the United States was "a prescription for stalemate".

Brazil called for a target limit on global temperature rises of no more than 0.2 degrees Celsius per decade.

Japan said global greenhouse gas emissions should peak "in the next 10 to 20 years". Nicaragua on behalf of Guatemala, Dominican Republic, Honduras and Panama, said global emissions should peak between 2010-2013.

A UN panel of climate scientists, the Intergovernmental Panel on Climate Change (IPCC), said emissions should peak by 2015 to avoid the worst impact of climate change, limiting warming to 2-2.4 degrees.

Several countries including Japan and China supported use of global carbon markets to trade emissions rights, which supporters argue reduces the cost of cutting greenhouse gases.