UN climate report must be ‘death knell’ for fossil fuels

The summary report from the IPCC provides a comprehensive picture of the impact human activity is having on the climate, bringing together climate data and physical sciences expertise from around the world, including drawing on the findings of more than 14,000 technical papers.

The 4,000-page report – the first instalment of the IPCC’s sixth assessment since the 1980s and the first since 2013 – has been approved by representatives of 195 governments prior to its publication.

At the UN COP26 climate summit in Glasgow in November this year, governments will present their plans for cutting greenhouse gas emissions aligned with the Paris Agreement target of keeping temperature rises within 1.5°C above pre-industrial levels. Remaining within this target temperature rise could help avoid the most devastating consequences of climate change.

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

The report concludes that it is “unequivocal” that human activity is warming the world. Rapid, widespread changes to land, atmosphere and oceans have already occurred in every region of world on a scale unprecedented for centuries or even millennia. These include rising sea levels (oceans rising 0.37cm a year and accelerating); vanishing Arctic Sea ice; retreating glaciers, and extreme weather events such as heatwaves, rainstorms, droughts and cyclones.

Anthropogenic climate change has caused global temperatures to rise by 1.1°C and the world is on track to reach or exceed the temperature limit over the next two decades. Temperatures will continue to rise to at least the mid-century whether emissions remain high or fall drastically. Without immediate and deep reductions in greenhouse gases, the world will exceed not only the 1.5°C target but also 2°C during this century.

The dangers to the natural and built environment are reiterated: changes to ocean levels, melting permafrost and glaciers will be irreversible for decades, centuries or even millennia, and urban areas will experience flash flooding and ever-hotter summers in heatwaves. Unlikely climate impacts such as ice sheet collapses; abrupt changes to ocean circulation, and warming above 2°C cannot be ruled out, the report concluded.

UN secretary-general Antonio Guterres described the IPCC report as “code red for humanity”, adding: “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. This report must sound a death kneel for coal and fossil fuels, before they destroy our planet.”

Scientists, governments and campaigners have almost unanimously called for a step-up in decarbonisation ambitions, piling pressure on governments to take action in the run-up to COP26.

Professor Corinne le Quere, a report author from the University of East Anglia, commented: “The message could not be clearer: as long as we continue to emit CO2, the climate will continue to warm and the weather extremes – which we now see with our own eyes – will continue to intensify. Thankfully, we know what to do: stop emitting CO2.”

Petteri Taalas, secretary-general of the World Meteorological Organisation, pressed the significance of the COP26 summit. Speaking at a press conference, he said: “Have we lost hope? No and yes. According to this report we still have a chance to stop the climate trend by the middle of this century by especially limiting the use of fossil fuels and by stopping deforestation. The forthcoming COP26 meeting in Glasgow this November will be a critical milestone to combat climate change.”

While it is too late to stop some changes, such as the continued melting of the Greenland ice sheet, the report lays out benefits of a range of constructive interventions, describing five future scenarios that could play out following the climate summit. Notably, temperature rises have a good chance of remaining below 1.5°C if carbon emissions are cut to net-zero by 2050 followed by subsequent efforts to go carbon negative while cutting other greenhouse gases drastically. It mentions the importance of cutting methane, strongly associated with petroleum drilling and livestock farming, which contributes to air pollution as well as global warming.

“Stabilising the climate will require strong, rapid and sustained reductions in greenhouse gas emissions and reaching net-zero CO2 emissions,” said climatologist Professor Panmao Zhai, co-chair of the working group that produced the report. “Limiting other greenhouse gases and air pollutants, especially methane, could have benefits for both health and the climate.”

Under the best (lowest emissions) scenario described by the report, sea levels will rise by 28-55cm this century. Under a scenario with very high greenhouse gas emissions, feedback loops will be triggered which release even more carbon, causing temperatures to rise by more than 4°C and sea levels to soar. At higher pollution levels, natural carbon sinks become less effective at absorbing greenhouse gases.

While many governments have set net-zero targets around the mid-century, report authors warned that pledged decarbonisation action is insufficient, putting the world on track to reach 2.7°C towards the end of the century if delivered fully. The Earth has never been so warm in the history of Homo sapiens (not since the Pliocene Epoch approximately three million years ago).

The report warned that “with every additional increment of global warming, changes in extremes continue to become larger.” For instance, every additional 0.5°C is associated with clearly discernible increases in the intensity and frequency of heatwaves, flooding and droughts.

“The 1.5°C or 2°C goals from the political process, they’re not cliff edges, we don’t fall off a cliff if we go over those thresholds, every bit of warming matters,” said Professor Ed Hawkins of the University of Reading, a lead author of the IPCC report. “The consequences get worse and worse as we get warmer and warmer and warmer, so every tonne of CO2 matters and every bit of warming matters.”

Responding to the report, UK prime minister Boris Johnson 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. I hope today’s IPCC report will be a wake-up call for the world to take action now, before we meet in Glasgow in November for the critical COP26 summit.”

Alok Sharma, president of COP26, said: “The science is clear, the impacts of the climate crisis can be seen around the world and if we don’t act now, we will continue to see the worst effects impact lives, livelihoods and natural habitats. Our message to every country, government, business and part of society is simple. The next decade is decisive, follow the science and embrace your responsibility to keep the goal of 1.5°C alive.”

Sharma called on governments to propose more ambitious 2030 emissions reduction targets in addition to long-term strategies with a pathway to net-zero by 2050. The UK government has formally adopted a target of net-zero carbon emissions by 2050.

Despite these statements, the UK government’s own climate credentials are under intense scrutiny. Last week, the prime minister and other senior ministers – as well as the First Minister of Scotland – avoided repeated questions over the future of the Cambo oil field off the coast of Scotland, insisting that the decision to approve the exploitation of the oil field, which would continue drilling until 2050, is out of their hands.

Shadow business secretary Ed Miliband – who introduced the UK’s first decarbonisation targets – commented: “The biggest threat we now face is not climate denial but climate delay, including from the UK government. The scene is now set for COP26, our last, best hope of a global breakthrough to limit temperature rises to 1.5°C. The message to the government here and those around the world is enough rhetoric, enough delay – the era of action is now.”

Liberal Democrat leader Sir Ed Davey wrote on Twitter: “There is still time to save the planet, but only if we act now. Boris Johnson’s dither and delay is costing us time we cannot afford, with drastic consequences. As host of COP26, the UK needs to lead the world in tackling the climate crisis. No excuses.”

Campaigners reiterated calls to halt future fossil projects such as the Cambo oil field. Jake Woodier of the Climate Coalition (which encompasses groups such as Oxfam, the WWF, the WI and the RSPB), said: “Climate change is already here and after a summer of chaotic and destructive weather, the public want Boris Johnson’s government to act decisively. We already know what’s needed to secure a safer future: from saying no to polluting fossil fuels to the Cambo oil field, to restoring the natural world, protecting forests and meeting financial promises to support people on the frontline of the climate crisis. Now, it’s time to get on and do it.”

Veteran IPCC author Sonia Seneviratne of ETC Zurich expressed doubts that she would continue to contribute, saying: “We have all the evidence we need to show we are in a climate crisis. Policy makers have enough information. You can ask: Is it a meaningful use of scientists’ time, if nothing is being done?”