The dangers of "overshooting" the Paris climate targets

• It was even included in the most recent U.N. IPCC assessment reports.

Zoom in: The paper, published on the popular academic writing site The Conversation, is written by three British scientists, including former IPCC head and past chief U.K. science adviser Robert Watson.

• The researchers argue that it's foolish and dangerous to heat the climate past 1.5°C above preindustrial levels, which is the Paris Agreement's most aggressive limit, and then reduce temperatures using as-yet unproven technologies, such as carbon dioxide removal or geoengineering.
• Instead, they advocate for rapid and drastic emissions reductions to prevent overshoot in the first place.
• The researchers write that "[t]o argue that we can safely overshoot 1.5°C, or any amount of warming, is saying the quiet bit out loud: we simply don't care about the increasing amount of suffering and deaths that will be caused while the recovery is worked on."

Yes, but: The carbon dioxide removal community, including some of the top companies in that burgeoning field, has repeatedly emphasized the need to cut emissions as much as possible.

• But cutting emissions enough to avoid exceeding the 1.5-degree target, beyond which risks of potentially catastrophic climate impacts escalate, would require taking steps that no nation is currently considering.
• "We need to do everything possible to avoid overshoot with reductions and be prepared for any degree of overshoot," said Dana Jacobs of the Carbon Removal Alliance.
• "At the same time, the climate models tell us we also need carbon removal for a different purpose: to count against emissions from sectors of the economy without ready zero-carbon solutions."

Experts not affiliated with the new piece disagreed with some aspects. They noted that many carbon-removal technologies are being designed to address hard-to-abate sectors, like steel manufacturing and aviation.

• "I do think there is a risk of being too cavalier about overshoot," climate researcher Zeke Hausfather told Axios via email. "Even if we get permanent carbon removal down to $100/ton (which is a big stretch given we are at well over $300/ton today on average) it's going to cost society $22 trillion to deal with 0.1°C overshoot."
• "I worry that we will just normalize the damages of an overshoot world rather than embark on the global-scale engineering challenge of atmospheric restoration."

• Andrew Dessler, a climate scientist at Texas A&M, who wasn't involved in the new paper, said the paper fails to acknowledge the reason more progress has not been made on climate change: the influence of the fossil fuel industry.
• "If we want to solve the climate problem, reducing the political power of fossil fuels is the first thing that needs to be addressed," he said.

Between the lines: The authors argue that the concept of net zero emissions, which many countries and corporations have committed to achieving, including the U.S., "is becoming detached from reality as it is increasingly relying on science fiction levels of speculative technology."

• An interesting take in the op-ed is that the Paris Agreement itself would have been more effective if it contained emissions reduction goals rather than temperature targets.
• "The time has come to accept that climate policy has failed, and that the 2015 landmark Paris agreement is dead," the researchers write. "We let it die by pretending that we could both continue to burn fossil fuels and avoid dangerous climate change at the same time."

The bottom line: There is wide agreement that emissions need to be reduced faster than they are, and that we're headed for more warming than the Paris pact prescribes. Overshoot is risky, studies have shown.

• But what to do about that — and how to approach the coming overshoot and existing net zero targets — is clearly contentious.