Kickstarting the transition to renewal energy must begin immediately to stop the world from “sleepwalking into a climate disaster”, Inger Andersen, executive director of the United Nations Environment Program, told journalists.

The landmark study, published late Monday following disagreements over its wording, details what countries must do to rein in global warming – warning that global emissions must peak by 2025.

It was compiled in collaboration with IPCC scientists and governments from some 200 countries who spent the last two weeks working on the document, which focuses heavily on the urgent need to phase out fossil fuels.

“It’s now or never, if we want to limit global warming to 1.5C,” said the co-chair of the IPCC working group, Jim Skea.

Experts have already warned emissions must be halved by 2030 if the world is to cap warming at 1.5C and stave off the most catastrophic impacts of climate change.

Mitigation

While the first in the IPCC report trilogy explained the scientific basis of climate change, the second looked at efforts to adapt to extreme events such as heat waves, floods and rising sea levels.

Monday’s report deals with the tricky subject of mitigation – and it will have implications for countries on the transformational decisions they will be forced to take in order to phase out fossil fuels by the end of the decade.

“It’s time to stop burning our planet and start investing in the abundance of renewable energy around us,” said UN Secretary-General Antonio Guterres.

“Current climate pledges would (still) mean a 14 percent increase in emissions – and most major emitters are not taking the steps needed to fulfil even these inadequate promises."

Choices made by countries now would "make or break" the commitment to 1.5C, Guterres added.

Record negotiations

Talks on the final text had continued past their deadline on Sunday – the longest negotiations in the IPCC's 34-year history – as governments haggled with scientists over questions of ending fossil fuel subsidies and providing funding for developing countries.

As well as the move to greener energy sources – solar, wind, hydro, hydrogen and even nuclear – the report also focuses on implementing the widespread use of technology to remove carbon from the atmosphere, growing forests and shifting towards plant-based diets.

Global temperatures are already at about 1.1C above the pre-industrial average.