Climate report is ‘code red for humanity’
Landmark IPCC study shows that ‘immediate, rapid and large-scale’ action is of the essence
The world will breach the Paris Agreement target to keep global warming below 1.5C as soon as 2030, the UN has warned, as it said climate change was already causing natural disasters.
Temperature rises are on course to exceed the key goal set out in the Paris Agreement, with severe consequences for climates around the world and sea levels, the Intergovernmental Panel on Climate Change said yesterday in a stark assessment of the world’s progress.
In the landmark report, written by hundreds of scientists and approved by 195 countries, scientists warned that “immediate, rapid and large-scale reductions” in greenhouse gas emissions are needed to keep alive any hope of keeping to the goal, established in 2015 as a threshold for avoiding the worst impacts of climate change.
Current sea level rises, heavy rainfall, drought and heatwaves can be ascribed to greenhouse gas emissions, the report said, with humanity’s influence on climate “unequivocal”, in the strongest assessment to date of the current science.
Natural disasters are likely to get worse with every increment of warming, the report added, and some effects, such as sea level rises of up to three metres if warming hits 1.5C, will be irreversible over thousands of years. Heatwaves have become more common and intense in recent decades because of climate change, with drought, flooding, “fire weather” and episodes of heavy rainfall also more severe.
Co-author Ed Hawkins, professor of climate science at the University of Reading, said: “We’re already experiencing climate change, including more frequent and more extreme weather events.
“The consequences will continue to get worse for every bit of warming, and for many of these consequences, there’s no going back.”
The findings came ahead of the Cop26 climate conference, set to be hosted by the UK in Glasgow in November, and mark the strongest warning yet from one of the most respected global bodies of scientists.
Prime Minister Boris Johnson said: “The next decade is going to be pivotal to securing the future of our planet. 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.”
UN secretary-general António Guterres said the findings represented “code red for humanity”.
“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,” he said.
Temperatures rising
The world is currently on track to hit the 1.5C climate target set out in 2015’s landmark Paris Agreement between 2021 and 2040. The Paris deal set out plans for countries to introduce emissions reductions in an effort to keep temperature rises below 2C while “pursuing efforts” to limit warming to 1.5C. Temperatures are already higher than pre-industrial levels by 1.1C.
In even the lowest-emission scenario set out in the report the 1.5C target is set to be reached by 2040, and then exceeded to hit 1.6C by 2060.
However, this “overshoot” will be corrected by the end of the century if there is a significant reduction in emissions. While scientists have previously suggested the world could breach the 1.5C target, they now have more certainty about the speed at which temperatures are rising and the impact of different levels of emissions.
Natural disasters
More severe weather and sea level changes caused by climate change have long been warned of by the IPCC, but this is the first time it has said current and recent events are also being driven by climate change.
Extreme weather is already becoming more likely due to a more intense water cycle, because warm air can hold more moisture – seven per cent more for every extra degree of warming, the report says.
Climate change has likely led to more frequent heavy rain, heatwaves, floods and droughts since the 1950s, and these trends will become more severe in future. In the UK particularly, an increase in flash floods as well as rising sea levels are likely to pose particularly serious threats.
‘The alarm bells are deafening, the evidence is irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet’
Irreversible changes
While rising temperatures can be halted if emissions come down, some of the impacts of that warming will endure for hundreds or even thousands of years, the report warns.
As of 2019, levels of carbon dioxide in the atmosphere were already the highest in two million years, meaning some changes are already happening, which won’t reverse quickly if emissions come down now.
Changes including sea level rises and deep ocean acidification are irreversible for “centuries to millennia”, while glacial melting will continue for “decades or centuries”.
Even if emissions fall to a very low level, up to half a metre of sea level rise is likely by the end of the century, with almost two metres likely under the highest-emissions scenario.
Humanity’s fault
The language in this report is significantly stronger than was used in previous instalments. In the 1990 Scientific Assessment report the authors said that they were “certain” global warming was happening and that humans were having some effect.
In more recent reports, including 2014’s instalment, warming was described as “unequivocal”, human influence as “clear” and it was “extremely likely” that humans had been the dominant cause of climate change since the mid-20th century.
Now, for the first time, the human influence has been described as “unequivocal”, with both greenhouse gas increases and temperature rises driven by human activity.
Emissions cut needed
Even if we do break the 1.5C and even the 2C barrier, every extra bit of warming counts, the report says.
It is “virtually certain” that temperature rises could be halted by reducing greenhouse gas emissions.
A cut in emissions now would lead to better outcomes within decades, with less extreme sea level rises, flooding and dangerous heatwaves.
Scientists and campaigners said plans to continue fossil fuel exploration were not compatible with the lowest-emission pathways necessary to have any hope of meeting the 1.5C target.