A key target to stop climate change raising global temperatures is under threat at a UN summit.
Climate change talks have been trying to limit the average rise in temperatures to 1.5C.
But at talks in the Egyptian resort of Sharm el-Sheik, there are concerns that target will slip.
Senior figures here in Egypt are worried about backsliding on efforts to keep the 1.5C goal.
There is a sense the Egyptian presidency is struggling to find common ground between rich and poor, and some delegates fear the focus on 1.5C may be softened to find agreement.
The limit is important because climate scientists say temperature rises must slow down if we want to avoid the worst consequences of climate change. They say global warming needs to be kept to 1.5C by 2100.
Ministers and their negotiators face an intensive week of talks in Sharm El-Sheikh as pressure grows to conclude this meeting with a strong political message.
According to the UN's climate chief, not enough progress has been made so far.
"My observations are that there are too many unresolved issues," Simon Stiell said to the meeting over the weekend.
"If we create a log-jam in the process, we will not deliver an outcome that is deserving of the crisis."
An analysis on the state of the negotiations by the Carbon Brief website shows widespread disagreement between parties.
One of the big concerns though is that as the organisers struggle to find a way forward, a clear statement on the commitment to 1.5C figure might be fudged.
In last year's Glasgow climate pact, all countries agreed to "keep 1.5C alive" by undertaking "rapid, deep and sustained" cuts in greenhouse gases.
But at a G20 meeting in Indonesia in August, ministers were unable to agree a communique on climate change, as China and India were reported to have questioned the scientific feasibility of the 1.5C threshold.
Such are the differences between countries here, there are fears that the final document being drafted by the Egyptians may dilute or exclude the 1.5C goal.
"I have been worried that there seems to some kind of attempt to say maybe 1.5C is not achievable anymore," the former President of Ireland, Mary Robinson, told the Irish Times on the sidelines of this summit.
"That is not acceptable," she said.
Mrs Robinson, who is chair of the Elders group of former political leaders, has released a statement with around 200 of the world's largest businesses and civil society groups urging governments to align their national targets with 1.5C.