The best possible future – one with fewer climate catastrophes, extinctions and human suffering – involves limiting global warming to 1.5 degrees Celsius. But for that to happen, a new report warns that greenhouse gas levels must start falling by 2025.
“We are on the fast track to climate catastrophe,” United Nations Secretary-General António Guterres said on Monday, announcing the new report by the United Nations’ preeminent climate body, the Intergovernmental Panel on Climate Change. climate change.
“This is neither fiction nor exaggeration,” he added. “That’s what science tells us will result from our current energy policies. We are on track for global warming to more than double 1.5 degrees. »
In 2016, virtually every country signed the Paris climate accord pledging to avoid the worst climate impacts by limiting global warming to well below 2 degrees Celsius, ideally 1.5 degrees Celsius, compared to preindustrial levels. But the world already has warmed by 1.1 degrees Celsiusand this new report makes it very clear that higher temperature goals may soon be out of reach unless humans immediately and radically change the way they live, from how they get energy and food to how they build and move.
“It’s now or never, if we want to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit),” said Jim Skea of Imperial College London, one of the co-authors of the report, in a press release. “Without immediate and deep emission reductions across all sectors, this will be impossible.”
Skea was one of hundreds of scientists around the world who contributed to the report titled “Climate Change 2022: Mitigation of Climate Change”, the third and final installment of the IPCC’s Sixth Climate Assessment. Previous issues, published in recent months, focused on summarizing climate impacts already here and what may be to come, as well as list ways to adapt to these impacts.
In the face of increasingly severe climate impacts, from intensifying heat waves and flooding to growing food disruptions, humans have spent the last decade adding fuel to the fire by continuing to spit out more carbon dioxide. carbon and other greenhouse gases into the atmosphere than ever before.
Global average emissions measured about 59 gigatonnes of carbon dioxide equivalent in 2019, about 12% higher than in 2010 and 54% higher than in 1990, according to the new report. This is a staggering increase.
But the responsibility for the increase in emissions does not fall on everyone in the same way.
“The 10% of households with the highest emissions per capita contribute a disproportionate share of global consumption. [greenhouse gas] emissions,” according to a summary of the new report. For example, in 2019, small island developing states are estimated to have emitted 0.6% of global greenhouse gas emissions.
The only way to prevent widespread climate damage is to stop this trend immediately. According to the report, to keep the future at 1.5 degrees Celsius, people around the world must collectively peak their emissions by 2025 and then reduce them by 43% by 2030. Importantly, this means reduce emissions of the powerful greenhouse gas methane by 34% by 2030.
Finally, by 2050, people must achieve net zero emissions, which is when they release the same levels of emissions into the atmosphere as they take out.
Even if all of these deadlines are met, scientists warn that it is still likely that global average temperatures will temporarily exceed, or “surpass”, 1.5 degrees Celsius, before falling back below that level by the end of the month. century.
Keeping even the 2.0 degree Celsius future within reach means peaking global emissions by 2025, the report says, then cutting emissions by 27% by 2030 and reaching net zero emissions by the early 2070s.
Perhaps the best way to reduce emissions is to quickly switch from fossil fuels to renewables and other alternative forms of energy. Limiting warming to 1.5 degrees, according to climate modeling, means reducing global use of coal, oil and gas in 2050 by around 95%, 60% and 45% from 2019 levels.
“Climate change is the result of more than a century of unsustainable energy and land use, lifestyles, and consumption and production patterns,” Skea said. “This report shows how acting now can move us towards a fairer and more sustainable world.”
The release of the report comes as Russia’s war in Ukraine has sparked energy costs soaring and so has conversations in Europe, the US and elsewhere faster move away from russian fossil fuels.
“We are currently facing difficult times. We have learned from this brutal war in Ukraine,” Petteri Taalas, secretary general of the World Meteorological Organization, said at Monday’s press conference, before linking the fighting on the ground to the fight to limit climate change. “In the best case, it would accelerate the reduction of fossil fuel use and also accelerate the green transition. In the worst case, the interests of mitigating climate change will be challenged because of this development.”