UN climate report: Carbon removal is now “essential”

Reducing emissions so quickly would require rapid transitions to new technologies, as well as sharp reductions in energy demand. That would require unprecedented human behavior changes and efficiency improvements, all of which would be “quite difficult to achieve in the real world,” says Zeke Hausfather, a contributor to a previous working group for the latest UN climate report and leader of climate research in Raya.

Loosening the target to 2˚C would essentially provide an additional decade to cut climate pollution in half, to 29 billion tonnes of emissions by 2040.

The speed and scale of the cuts required in both cases are simply not realistic, says Julio Friedmann, chief scientist at Carbon Direct, a research and investment firm focused on carbon removal. Nations will need to do “enormous” levels of carbon removal, he says.

The essential problems: The world has already emitted too much. We haven’t done enough to shift to cleaner ways of running our economies. And we still don’t have available and affordable ways to fix certain industries and products, like aviation, shipping, fertilizer, cement, and steel.

The promise of carbon removal is that it can give nations more time to switch to sustainable practices and balance ongoing emissions from sources we don’t know how to replace.

But …

two. We’re going to have to do a lot of that

Keeping the planet from warming 2˚C, or causing the climate to regress, could require removing billions of tons of carbon dioxide each year.

Models that limited warming to 2˚C relied on three main methods of carbon removal: planting trees, restoring forests, and adopting similar land management practices, developing and deploying carbon-scavenging machines, and relying on plants to produce energy while capturing emissions, known as BECCS. Together, they would need to remove up to 17 billion tons of carbon dioxide a year by 2050 and 35 billion by 2100, according to the report.

3. We need a portfolio of carbon removal options

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

Nature-based approaches such as tree planting and forest restoration, for example, are the most widely used today. But the carbon can go back into the atmosphere when plants die or are burned in fires. Therefore, these solutions are likely to have a shorter life than other methods, such as geological storage, which lock carbon underground.

Direct air capture can permanently remove and store carbon, but the machines are currently limited in scale and expensive, and the technology consumes large amounts of energy and water, the report notes.

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

The report points to a wide variety of other ways to capture carbon dioxide, including ocean-based approaches such as using minerals to increase the alkalinity of seawater. But these are largely untested.

4. Enlargement will require financing and political decisions

The climate panel authors stress that achieving high levels of carbon removal will require significant research and development to determine the most effective methods, minimize environmental impacts, and rapidly develop major real-world projects.

“We need all hands on deck to explore a diverse set of options to implement deep decarbonization and remove carbon dioxide,” wrote Frances Wang, program manager for the ClimateWorks Foundation, which funds carbon removal research efforts. , in response to a technology review from MIT. consultation.

Probably the biggest hurdle to building a major carbon removal industry is cost. Who is going to pay for the hundreds of billions to trillions of dollars needed to remove so much carbon dioxide year after year?

The report says that accelerating research and development on carbon removal, and getting companies to actually do it, will require “political commitment” from governments. That means enacting policies to require or incentivize carbon removal, as well as methods to ensure practices are achieving claimed climate benefits.

If history is any guide, the grim findings of a new IPCC report won’t radically change anything. The world is emitting about 6 billion tons more emissions annually than when the last major assessment was published, in 2014. But more and more work is being done on carbon removal as the importance of its role in combating climate change becomes increasingly clear. .

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