Humanity has so far failed miserably in its quest to fight climate change, and it is running out of time to make the sharp cuts to greenhouse gas emissions that might avert the worst harm to people and the planet, according to the latest report from the Intergovernmental Panel on Climate Change (IPCC).
“It is a file of shame, cataloging the empty pledges that put us firmly on track toward an unlivable world,” said U.N. Secretary-General António Guterres at a press conference on Monday.
Climate scientists detailed an “atlas of human suffering” in the last IPCC analysis, released in late February, describing in a United Nations-backed report the devastating and growing impacts of the changing climate on people and ecosystems across the world. Monday’s report explained what it would take to avoid some — though not all — of that suffering.
The ideal outcome — to the extent that any outcome can be “ideal” at this point — is holding the rise in temperature to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above that of the pre-industrial era. This will not be easy. The secondary goal would be to limit warming to 2 degrees Celsius. This is still far from trivial.
The findings in this “file of shame” help paint a picture of urgent need, significant difficulty and, perhaps surprisingly, substantial opportunity. Here are a few of the details.
1) Emissions need to peak quicker than we thought
The standard line on greenhouse gas emissions in recent years has been that they need to drop by about half by 2030, reaching net zero around mid-century. The new IPCC report takes this a step further: The pathways that keep the world to 1.5 or 2 degrees Celsius of warming all require emissions peak “between 2020, and at the latest, before 2025.”
The world is not close to meeting this goal. Though the covid pandemic offered a brief reprieve, global emissions have continued to rise, and there is no indication the peak is imminent. China, by far the world’s largest annual greenhouse gas emitter, pledged last year that it would peak its emissions by 2030, well beyond when the new report says holding warming to 1.5 degrees Celsius will be out of reach. India, third in the world behind China and the U.S., sees an emissions peak coming only in 2045, or afterward.
“It’s now or never,” said Jim Skea, co-chair of the new report and Imperial College London professor of sustainable energy. “Without immediate and deep emissions reductions across all sectors, it will be impossible.”
2) We’ve already built too much fossil fuel infrastructure to stay at 1.5 degrees Celsius
It has been clear for quite some time that building brand new fossil fuel infrastructure — coal and gas power plants, oil and gas pipelines, and more — doesn’t mesh with climate targets. But it turns out just using what’s already out there will take us past 1.5 degrees Celsius.
Keeping warming to that level requires emitting no more than 510 gigatons, or billion tons, of greenhouse gas emissions before reaching net zero. Assuming continued normal operations, existing fossil fuel infrastructure will emit 660 gigatons, according to the new report. If you add in all planned fossil fuel infrastructure, that number rises to 850 gigatons, not far from the 890 gigatons that will likely lock in 2 degrees of warming.
Other recent reports have shown how major financial institutions continue to invest billions in fossil fuel projects, in spite of some very climate-friendly rhetoric. Clearly, those investments need to drop to zero in a hurry if the targets are to be met.
3) The power sector is the best opportunity to decarbonize in a hurry
The IPCC projects that to keep warming even below 2 degrees Celsius, most of the emissions from now until net zero must come from outside the electricity sector. That’s because cutting emissions from electricity is actually the easy part.
Decommissioning existing power plants quicker than previously planned, switching to lower-carbon fuels and canceling plans for new power plants — along with the continued precipitous drop in the cost of solar and wind power — could rapidly decarbonize the power sector. The real climate challenge, and where most of those remaining emissions will come from even in an ideal scenario, is with heavy industry and transportation.
The use of steel, cement, plastics and other materials continues to increase globally, according to the report. “Achieving net zero will be challenging and will require new production processes, low- and zero-emissions electricity, hydrogen, and where necessary, carbon capture and storage,” said report Vice Chair Diana Ürge-Vorsatz, a professor of environmental sciences and policy at Central European University in Hungary.
Transportation may have a slightly clearer path to decarbonization, though no less difficult. Switching to sustainable biofuels and electric vehicles powered by clean sources will make a dent, but increasing demand is again going to act as a roadblock. The report notes, though, that transportation mitigation efforts have substantial co-benefits, including to air quality and human health.
4) We need to suck carbon dioxide out of the sky
Removing carbon dioxide from the air remains more or less an aspirational technology at this point. The world’s largest facility designed to pull CO2 from the atmosphere and store it underground in Iceland can only manage the equivalent of taking 790 cars off the road each year — at a price point that very few could stomach. But the new IPCC report makes clear that simply cutting emissions is not enough.
“Carbon dioxide removal is essential to achieve net zero,” Ürge-Vorsatz said. At least in the near term, this is another big ask. There are low-tech CDR approaches including reforestation, allowing trees to do the hard work of removing CO2 from the atmosphere, but large-scale technological approaches have stubbornly failed to come down in cost. The report blandly undersells this challenge: “Upscaling the deployment of CDR depends on developing effective approaches to address feasibility.”
5) It’s cheaper to do this than to not do it
The IPCC report isn’t all doom: It says that existing tools could cut about half of 2019′s greenhouse gas emissions by 2030, at a cost of $100 per ton or less. And more than half of that could be done with options costing $20 per ton — far below what the Biden administration set as the social cost of carbon or the cost to society of emitting one ton of CO2.
More generally, the costs of aggressively cutting greenhouse gas emissions are small when compared with the projected growth in global gross domestic product over the next few decades. And the actual costs of unmitigated climate change are massive, as manifested in everything from crop losses to destroyed coastal cities. As the IPCC, again with the benefit of scientific understatement, put it: “The global economic benefit of limiting warming to 2°C is reported to exceed the cost of mitigation in most of the assessed literature.”
Cost is often cited as a reason to delay when it comes to climate action. This has been something of a red herring for many years with economic reports consistently showing the outsized benefits from a clean energy transition, and the new IPCC math lays this bare even further.
“Today’s report comes at a time of global turbulence,” said Guterres. “Climate promises and plans must be turned into reality and action now. It’s time to stop burning our planet and start investing in abundant renewable energy all around us.”