A critical 12 months in the battle against rising temperatures begins in Madrid this week, as UN delegates gather for key talks.
The 25th Conference of the Parties, or COP, will see negotiators from almost 200 countries in attendance.
Ahead of the meeting the UN secretary general has warned that the world is at the point of no return.
António Guterres said the global response to date has been "utterly inadequate".
The conference takes place amid a welter of bad news on climate change in recent days.
The World Meteorological Organisation announced that greenhouse gas concentrations reached their highest recorded level in 2018.
The UN Environment Programme showed that there's a huge gap between the plans that governments currently have on the table to cut emissions and what's needed to keep under 1.5C. Keeping to that guardrail will need a five-fold increase in the carbon cutting ambitions of countries.
The UN Secretary General warned delegates ahead of the meeting "the point of no return was no longer over the horizon".
"We simply have to stop digging and drilling and take advantage of the vast possibilities offered by renewable energy and nature-based solutions," Mr Guterres said.
As well as demanding that the negotiators increase their level of carbon cutting ambition at this meeting, Mr Guterres announced that the Governor of the Bank of England Mark Carney will take on the role of UN Special Envoy on climate action and climate finance.
