The latest report from the Intergovernmental Panel for climate change “is a code red for humanity”, according to UN secretary general António Guterres.
“The alarm bells are deafening, and the evidence is irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet and putting billions of people at immediate risk. Global heating is affecting every region on Earth, with many of the changes becoming irreversible,” he said in response to the report issued on Monday.
The internationally agreed threshold of 1.5 degrees is perilously close, Mr Guterres warned. “We are at imminent risk of hitting 1.5 degrees in the near term. The only way to prevent exceeding this threshold is by urgently stepping up our efforts, and pursuing the most ambitious path. We must act decisively now to keep 1.5 alive,” he added.
The world was already at 1.2 degrees and rising, he noted, while warming has accelerated in recent decades. "Every fraction of a degree counts. Greenhouse gas concentrations are at record levels. Extreme weather and climate disasters are increasing in frequency and intensity. That is why this year's United Nations climate conference in Glasgow [in November ]is so important," he said.
The viability of our societies depends on leaders from government, business and civil society uniting behind policies, actions and investments that will limit temperature rise to 1.5 degrees, Mr Guterres insisted. “We owe this to the entire human family, especially the poorest and most vulnerable communities and nations that are the hardest hit despite being least responsible for today’s climate emergency.”
Christian Aid's climate policy lead Dr Kat Kramer said: "Science has spoken: urgent climate action is needed to cut emissions rapidly and deeply or the whole world, especially the people on the frontline, will be plunged further into peril and poverty."
The report puts carbon dioxide emissions firmly in the firing line, she believed, reinforcing the need for net-zero emissions. “These findings clearly show the need to end the fossil fuel era and to move to a future based on efficiency and renewables, while creating access to energy for those in poorer countries that currently lack it,” she added.
“So far political will to act has been wildly inadequate. Current national pledges put us on a pathway to a 2.4-degree world, which the IPCC shows would sentence people to more and fiercer heatwaves as well as droughts in some regions. Theses impacts will be most devastating to the world’s already-vulnerable people,” Dr Kramer said.
Prof Nigel Arnell, a specialist in climate system science, who contributed to the report, said it confirms "human activities have changed our climate and led to the more frequent heatwaves, floods, droughts and wildfires that we have seen recently. The evidence is incontrovertible".
It also shows impacts will continue to increase virtually everywhere, and only by major reductions in emissions – achieving net zero – will there be a chance of meeting the internationally-agreed climate targets. “We now have a greater understanding of how quickly risks will change, and several very damaging plausible ‘worst case’ scenarios cannot be ruled out,” Prof Arnell pointed out.
Climate justice campaigners called for a "total systemic overhaul" at this year's COP26 global summit, given the report is "a terrifying warning of our future". "Our political class refuses to face up to the fact that it is rooted in economics and colonial exploitation," said Global Justice Now head of policy Dorothy Guerrero.
“We’re reaching the point of no return on climate breakdown. Laissez-faire climate policies have not worked and this report is a terrifying warning of our future unless drastic action is taken. There is no denying the science of the climate crisis. But policymakers refuse to face up to the fact that it is rooted in economics and a history colonial exploitation,” she added.
Prof William Collins, Professor of Meteorology, University of Reading said: "This report details the climate changes in heatwaves and extreme rainfall that we have already experienced due to our emissions of greenhouse gases" in a scenario where current levels of carbon dioxide have not been seen in the past 2 million years.
“Most of this warming has been caused by carbon dioxide, but a new finding is that a substantial fraction (around half a degree) has been due to emissions of methane, which comes from sources such as oil and gas drilling and agriculture.