The impacts of climate change—worsening heatwaves, droughts, wildfires, floods, and more—are already happening today, and may be irreversible, according to the latest report from the Intergovernmental Panel on Climate Change (IPCC). The report is the world’s most authoritative summary of climate science, compiled by hundreds of scientists about twice per decade since 1990.
The report projects that in the most likely scenario, global temperatures will increase more than 1.5 degrees Celsius above pre-industrial levels by the early 2030s (from about 1.1C today). That’s a decade earlier than projected in the previous IPCC report in 2013, and would produce increasingly devastating consequences for every continent.
Yet among the report’s findings is a small sliver of optimism: it’s still not too late to limit warming to 1.5C—the goal enshrined in the 2015 Paris Agreement—if the global economy rapidly transitions away from fossil fuels, starting today. But the report makes clear that merely cutting off new greenhouse gas emissions is no longer enough. Every fraction of a degree makes a significant difference for climate impacts—and the only way to stave off the worst warming is to significantly scale up carbon removal technologies.
“Doing the work today to sort out how to responsibly and sustainably remove carbon dioxide from the atmosphere is now essential,” said Simon Nicholson, co-director of the Institute for Carbon Removal Law and Policy at American University.
Carbon removal refers to pulling existing CO2 out of the atmosphere, with methods ranging from simply planting trees to building gigantic carbon-sucking machinery. Carbon removal is essential because China, India, and other emerging economies will continue to use fossil fuels for energy for years after the US and Europe have largely phased them out, and because a few sectors of the economy, like aviation and steel production, will also likely rely on fossil energy for decades.
To reach net zero global emissions before 2050—which the IPCC suggests is the only hope of sticking to 1.5C—those emissions will have to be offset by carbon removal. By 2050, the US alone may need to remove the equivalent of one-third of its current annual emissions every year.
But while carbon removal can be a significant tool for managing temperature increase this century, it may take hundreds of years before it would make an impact on the trajectory of sea level rise—meaning that stopping new emissions is still the top priority.
“There’s an important interplay between the scale and pace of emissions reductions and the role for carbon removal,” said Kelly Levin, chief of science, data, and systems change at the Bezos Earth Fund. “The faster you peak emissions, the less you rely on carbon removal. But to be able to have those options by midcentury, you require a significant amount of research and development and piloting today.”
A growing number of companies are already doing that work, and drawing in hundreds of millions of dollars in investment. At scale, their businesses will likely revolve around the sale of carbon offset credits to companies that can’t decarbonize quickly on their own. There are also startups working to use captured CO2 as a raw material for manufacturing cement and other products.
But the industry remains in its infancy, and the cost of direct air capture per ton of CO2 remains much higher—up to $600—than the cost of carbon pollution credits in the EU and other regions covered by carbon trading markets. To keep the planet habitable, those costs must come down dramatically–and soon.