BERLIN • Carbon-cutting pledges from 146 nations for a universal climate pact leave the "door open" to capping global warming below the danger threshold, the United Nations said yesterday, a month ahead of a crucial summit in Paris.

But even if these 10- to 15-year plans are fulfilled, humanity will have used up three-quarters of its carbon "budget" by 2030 and must slash greenhouse gas outputs even more to avoid devastating climate impacts, the UN's Climate Change Secretariat warned.

"An unprecedented worldwide effort is under way to combat climate change, building confidence that nations can cost-effectively meet their stated objective of keeping a global temperature rise to under 2 deg C," it said.

At the same time, "much greater emissions reduction efforts... will be required" to meet that target, it added.

As they stand, the pledges place the world on track for warming of some 2.7 deg C by 2100 - "by no means enough, but a lot lower than the estimated four, five or more degrees of warming" that would have otherwise taken place, said UN climate chief Christiana Figueres.

If countries commit in Paris to periodically revising their ambition upward, the goal stays within reach, she added.

AGENCE FRANCE-PRESSE