A new UN report warning humans are unequivocally driving global warming is a “wake-up call for the world”, Cop26 president Alok Sharma has said.

The assessment from the UN’s Intergovernmental Panel on Climate Change (IPCC) drew a stark picture of the impact humans are having through activities such as burning fossil fuels – and the future the globe faces if it fails to rapidly tackle the crisis.

The world will reach or exceed temperature rises of 1.5C – a limit countries have pledged to try to keep to in order to avoid the most dangerous consequences of warming – over the next two decades, the report says.

Mr Sharma said: “I have to say I think if ever there was going to be a wake-up call for the world when it comes to climate, then it is this report and it does show all too clearly the impact of human activity and, indeed, the deficiency of our response to date and why we need to act now on what the science is telling us.”

Speaking during a panel discussion in London, Mr Sharma added: “The future, of course, is not yet written and the very worst of climate change is still avoidable… and what this report shows, that 1.5 degrees is still achievable, but that it is retreating and it’s retreating fast.

“We do need to follow the science and we need to take action this year and make sure that at Cop26 we are able to credibly say that we have kept 1.5 degrees alive.”

He urged “all the major emitters to play their part”, adding the G20 group of nations “is going to be absolutely key in terms of our 1.5-degree future”.

Mr Sharma said countries who are attending the international Cop26 climate talks in Glasgow in November “must send a clear market signal to get the transition moving faster”.

The UN’s summary report was released following its approval by representatives of 195 governments, who now face pressure to take more action to cut emissions in the run-up to Cop26.

It makes clear that human-caused climate change, which has pushed up global temperatures by 1.1C, is driving weather and climate extremes in every region across the world.

One of the report’s lead authors, Dr Tamsin Edwards, from King’s College London, said: “Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, the 1.5C target will be beyond reach.”

UN secretary-general Antonio Guterres described the report as a “code red for humanity” and scientists, campaigners and politicians lined up to call for a shift away from polluting fossil fuels and to end deforestation.

Speaking at an IPCC press conference on Monday, Inger Andersen, executive director of the UN Environment Programme, warned “it is time to get serious” and that “no-one is safe” during the climate crisis.

ENVIRONMENT Climate
(PA Graphics)

Prime Minister Boris Johnson said the report makes for “sobering reading”, adding “it is clear that the next decade is going to be pivotal to securing the future of our planet”.

He said: “We know what must be done to limit global warming – consign coal to history and shift to clean energy sources, protect nature and provide climate finance for countries on the frontline.”

Labour leader Sir Keir Starmer said: “The IPCC report is the starkest reminder yet that the climate crisis is here right now and is the biggest long-term threat we face. The biggest threat we now face is not climate denial but climate delay.”

Connor Schwartz, climate lead at Friends of the Earth, said:  “Every fraction of a degree now matters more than ever. Loud wake-up calls have been sounding for years but world leaders have chronically over-slept, and people are paying the price with their lives.

“If we want a habitable planet, the window is just about still open, that’s today’s report in a nutshell.”

The study, which focuses on the physical science of climate change, forms the first part of the IPCC’s sixth assessment report, and is even clearer on the impact humans are having on the planet than the last such analysis in 2013.

It draws on more than 14,000 scientific papers to reach its conclusions and has found it is “unequivocal” that human activity is warming the world.

The report assesses the potential impact of a range of five future scenarios from very low emissions to very high pollution, highlighting the impacts of the choices the world makes now.

Temperature rises have a good chance of remaining below 1.5C in the long term if carbon emissions are cut to net zero by 2050, it says, followed by efforts to take more carbon dioxide out of the air than is put into the atmosphere, along with deep cuts to other greenhouse gases.

Scientists who worked on the report said current pledges of action on emissions put the world on a pathway that could lead to 2.7C of warming by the late 21st century – or higher if the pledges were not delivered on.