Jul 23, 2019

The limited case for direct air capture

Illustration: Rebecca Zisser/Axios

Nascent tech that pulls CO2 from the atmosphere could "significantly" reduce the costs of fighting climate change, but achieving scale is hardly a sure thing and massive deployment would consume lots of energy, a new peer-reviewed study warns.

Why it matters: The paper in Nature Communications arrives amid increasing attention to direct air capture (DAC) and other negative emissions technologies. They're important because it looks pretty unlikely that nations will cut emissions enough to meet the goals of the Paris climate deal.

  • The firm Carbon Engineering — whose backers include Bill Gates and oil giants Chevron and Occidental — recently announced plans for a big DAC plant in Texas.

What they found: According to the study, widespread deployment down the road would create a longer cushion to achieve steep emissions cuts.

  • In one scenario they modeled for holding global temperature rise to 1.5°C, it pushes the horizon for achieving "net-zero" emissions back from 2050 to roughly 2070, which would be "compensated by larger negative emissions thereafter."

Threat level: If policymakers wrongly bet on large-scale deployment, it could lead to a global temperature "overshoot" of up to 0.8 °C. That's a lot, given that Paris aims to limit the total increase to 1.5°C–2°C above preindustrial levels.

  • And large-scale deployment (think tens of thousands of big machines under one tech scenario), if even proven feasible would need to be really large, and that's not without consequences.
  • In theory, a huge buildout would consume as much as a fourth (!) of global energy demand to power and heat the systems by 2100, the paper notes.

The bottom line: The paper warns that DAC should not be viewed as a crutch, but rather as complementary to emissions-cutting strategies.

  • The authors recommend that policymakers speed up development and deployment, but "without easing near-term mitigation efforts" due to risks of the tech underperforming or failing.

Go deeper, via Carbon Brief: Direct CO2 capture machines could use ‘a quarter of global energy’ in 2100

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China's carbon emissions may peak as soon as 2021

Illustration: Rebecca Zisser/Axios

Carbon emissions from China could peak as soon as 2021, which is nine years before the voluntary deadline in their Paris agreement pledge, a new peer-reviewed study finds.

Why it matters: China is by far the world's largest carbon emitter. The trajectory of its emissions affect whether the world has any chance of meeting the Paris temperature goals — or, more likely, how much they're overshot.

Go deeperArrowJul 30, 2019

New working paper makes case for "modest" carbon taxes

Data: Knittel, 2019; Chart: Harry Stevens/Axios

Even "modest" carbon taxes, like those seen in the chart above, would cut emissions as much as the Obama-era vehicle and power plant rules that President Trump is abandoning, an MIT economist found in a new working paper.

Why it matters: The results "underscore the economic power of a carbon tax" compared to "economically inefficient" regulations, writes Christopher Knittel, who directs the MIT Center for Energy and Environmental Policy Research.

Go deeperArrowAug 16, 2019

A push from Congress could help advance carbon management tech

A direct air capture project site outside Reykjavik, Iceland. Photo: Melanie Stetson Freeman/The Christian Science Monitor via Getty Images

As the risks of climate change mount, the U.S. continues to lag behind other parts of the world, especially Europe, in funding R&D for carbon management and other innovative technologies.

The big picture: Government leadership could help fund early-stage research and spur private sector investment in a potentially $1 trillion market. Congress is aiming to advance this goal through several new bills — including the Senate's EFFECT Act, which would establish a Department of Energy program to use carbon dioxide as a resource for profitable products.

Go deeperArrowAug 2, 2019