The best possible future – with fewer climate disasters, extinctions and human suffering – involves limiting global warming to 1.5 degrees Celsius. But for this to happen, a new report warns, greenhouse gas levels would have to start falling by 2025.
“We are on the fast track to climate catastrophe,” UN Secretary-General Antonio Guterres said Monday in a new report by the UN’s lead climate agency, the Intergovernmental Panel on Climate Change.
“This is not fiction or exaggeration,” he said. “Science says it’s caused by our current energy policies. We’re on track to double global warming to 1.5 degrees.
In 2016, practically every country signed the Paris Climate Agreement, pledging to curb the worst climate impacts by limiting global warming to well below 2 degrees Celsius, ideally 1.5 degrees Celsius. But the world has already warmed 1.1 degrees Celsius, and this new report makes abundantly clear that warming targets may soon be reached if humans do not immediately and radically change how they live. They build and roll.
“It’s now or never if we want to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit),” Jim Schia of Imperial College London, one of the report’s co-authors, said in a statement. “Without immediate and deep emissions cuts in all sectors, that will be impossible.”
Schia is one of hundreds of scientists worldwide who contributed to the report, “Climate Change 2022: Mitigation of Climate Change,” the third and final installment of the IPCC’s Sixth Climate Assessment. Previous installments, published in recent months, have focused on summarizing the effects of climate change already and what is likely to come, as well as listing ways to adapt to these effects.
Faced with the effects of an ever-worsening climate, from intensifying heat waves and floods to growing food shortages, humans have added fuel to the fire over the past decade by continuing to spew more carbon dioxide and other greenhouse gases into the atmosphere than ever before.
Global average emissions measured roughly 59 gigatons of carbon dioxide in 2019, about 12% higher than levels in 2010 and 54% higher than in 1990, according to a new report. This is a staggering increase.
But the blame for rising emissions does not fall equally on everyone.
“The 10% of households with the highest per capita emissions account for a disproportionately large share of global emissions [greenhouse gas] emissions,” according to a summary of the new report. For example, in 2019, small island developing states were estimated to have emitted 0.6% of global greenhouse gas emissions.
The only way to prevent widespread climate damage is to halt this trend immediately. To keep a 1.5 degree Celsius future alive, people worldwide must collectively maximize their emissions by 2025 and then reduce emissions by 43% by 2030, according to the report. Importantly, this includes cutting emissions of the powerful greenhouse gas methane by 34% by 2030.
Finally, by 2050, people must achieve net zero emissions, meaning they emit the same level of emissions they emit into the atmosphere.
Even if all these deadlines are hit, scientists still warn that global average temperatures are likely to temporarily exceed, or “overshoot” by 1.5 degrees Celsius before returning to below that level by the end of the century.
Even reaching a 2.0 degree Celsius future would include global emissions by 2025, according to the report, then reducing emissions by 27% by 2030 and achieving net zero emissions by the early 2070s.
Perhaps the single biggest way to cut emissions is to rapidly transition from fossil fuels to renewable and other alternative energies. Climate modeling suggests that limiting warming to 1.5 degrees would cut global consumption of coal, oil and gas by roughly 95%, 60% and 45% in 2050 compared to 2019 levels.
“Climate change is the result of more than a century of unsustainable energy and land use, lifestyles and consumption and production patterns,” Schia said. “This report shows how taking action now can move us towards a better, more sustainable world.”
The release of the report shows that Russia’s war in Ukraine has driven up energy costs, and as such, conversations in Europe, the United States and elsewhere are rapidly shifting away from Russian fossil fuels.
“We are facing challenging times at the moment. We learned about this brutal war in Ukraine,” World Meteorological Organization Secretary-General Petteri Talas told a news conference on Monday, before linking the fight on the ground to the fight to limit climate change. “In the best case, this will accelerate the reduction of fossil energy use and accelerate the green transition. In the worst case, this development will challenge the interests of mitigating climate change.”