UN climate change negotiations in Lima have entered a tense second week with governments showing signs of backing away from moves to strengthen emission curbs to levels capable of preventing catastrophic warming.

Dozens of environment ministers are due to arrive in Peru today to join the thousands of government officials, observers and journalists from almost 200 countries at the two-week long meeting, which aims to smooth the path to a new global agreement next year.

Hopes were high going into the talks that goals announced last month by the world’s two biggest emitters of heat-trapping greenhouse gases – China and the US – would speed efforts to streamline text to manageable levels that could eventually be signed by all countries at next December’s summit in Paris.

But tension spilled over late on Friday and into Saturday following days of procedural wrangling when richer nations including the EU, Australia, Canada and New Zealand attempted to strip out any reference to a review or revisit of their current emission reduction commitments.

This “slash and burn exercise” risks “a quid pro quo pushback by developing countries that is not healthy for the negotiations,” said Tasneem Essop of environmental group WWF said, ahead of a Sunday pause in the talks.

2020 Targets

In another strand of negotiations, China led efforts to remove even the loosest external upfront questioning of the post-2020 emission contributions all countries are expected to make early next year under the new agreement, known as intended nationally determined contributions (INDCs).

U.N.-backed scientists say rising greenhouse gas emission levels must peak by the end of the decade to stand a chance of keeping global temperature rises beneath two degrees Celsius and limiting the worst impacts of climate change, including extreme weather and sea level rise.

The U.N.’s top climate diplomat Christiana Figueres said it was clear that scaling up efforts will be essential to close the gap towards safe atmospheric levels.

“We already know that all the national contributions that are going to come forward will not actually close the gap, this is going to be a gradual process over time.”

Environmental campaigners say that a review process is important to give formal recognition to the emission gap as a first step towards closing it.

“It’s like Alcoholics Anonymous, the first step is to admit that you’ve got a problem,” said Alden Meyer of the Union of Concerned Scientists.

Typhoon hits

Campaigners made a plea for unity and stressed the need to accelerate global action as Typhoon Hagupit slammed the central Philippines, forcing the evacuation of 900,000 people and threatening the recovery of a region devastated by Typhoon Haiyan a year earlier.

“To us in the Philippines we are not any more debating on whether or not the impacts of climate change are here. We have experienced it,” said Voltaire Alferez of Philippines’ Aksyon Klima environmental group told journalists.

“In the face of worsening impacts, like sea level rise, we do not want sympathy or pity, we want solidarity and action for those of us in vulnerable countries. We need this process to deliver.”

Decision time

Nations have already agreed that the Paris deal would consist of a framework of post-2020 contributions from all countries and in Lima must decide what each should include in order to meet a deadline to submit them next March.

But governments are split broadly between rich and poor nations on whether the contributions should include binding financial aid commitments by the rich to support the poor.

The thorny issue of working out which countries should make the strictest types of contributions, was given new direction by a new proposal by Brazil.

Brazil suggested a move away from the previous firm divide between developed and developing countries with three potential categories of effort according to a nation’s capabilities, with all eventually moving to the strictest tier of taking on economy-wide absolute emission targets.