UN Climate Report: Carbon Removal Is Now “Essential”

by James Temple andCasey Crownhart (MIT Technology Review) Removing the greenhouse gas from the air will likely be necessary, along with radical emissions cuts, to keep temperatures from rising 2˚C. -- A bleak new report from the UN’s climate panel underscores the price the world is paying for the long delays in addressing global warming despite decades of warnings.

“Carbon dioxide removal is essential to achieve net zero [greenhouse-gas emissions],” Diána Ürge-Vorsatz, vice-chair of the working group that produced the nearly 3,000-page report, said during a conference call on Monday.

The report concludes that nations will need to drastically cut emissions across all sectors, including transportation, energy, and heavy industry. That will require steep and swift shifts from fossil fuels to clean energy sources, as well as major changes in the way we produce food and other goods.

The report dedicates a chapter to carbon removal, highlighting just how big a role it may have to play, and how challenging it could be to achieve the levels required in the coming decades.

1. Carbon removal is basically non-optional

2. We’re going to need to do a whole lot of it

The models relied on three main methods of carbon removal: planting trees, restoring forests and adopting similar land management practices, developing and deploying carbon-sucking machines, and relying on plants to produce energy while capturing the emissions, which is known as BECCS. Keeping temperatures "likely" below 2 ˚C could require as much as 11 billion tons of carbon dioxide per year by 2050 and 20 billion by 2100, according to the report.

3. We need a portfolio of carbon removal options

The report stresses that different approaches to carbon removal have very different benefits and challenges.

Nature-based approaches like planting trees and restoring forests, for instance, are the most widely deployed today. But the carbon can go right back into the atmosphere when the plants die or burn up in fires. So these solutions are likely shorter-lived than other methods like geological storage, which locks carbon away underground.

The IPCC report’s models lean heavily on BECCS, which is a hybrid of nature-based and technology-based approaches, with some of the benefits of each. BECCS, however, requires vast amounts of land that could compete with the needs of food production, among other challenges.

4. Scaling up will require funding and policy decisions

The biggest hurdle to building up a major carbon removal industry is likely to be cost. Who is going to pay the hundreds of billions to trillions of dollars it will run to remove this much carbon dioxide year after year? READ MORE