Centuries of net-negative emissions required to secure a safe climate future

[OKIsItJustMe]

So… this means it’s someone else’s problem, right?

https://iiasa.ac.at/news/mar-2026/centuries-of-net-negative-emissions-required-to-secure-safe-climate-future

Two new studies published in leading scientific journals conclude that stabilizing long-term climate risks will require sustained net-negative carbon dioxide (CO₂) emissions for centuries. Approaching the problem from distinct perspectives – legal and technological feasibility on the one hand, and economic optimization under uncertainty on the other – the research converges on a consistent message: reaching net zero is not enough.

Both studies were led by researchers from the Exploratory Modeling of Human-natural Systems Research Group of the IIASA Advancing Systems Analysis Program and underline that achieving the Paris Agreement goals will demand durable commitments to large-scale carbon dioxide removal (CDR) extending far beyond current policy timelines.

…

The implications for policymakers are profound. Many countries projected to become wealthier after mid-century – while simultaneously facing increasing exposure to sea-level rise and permafrost thaw – have strong incentives to adopt more ambitious Nationally Determined Contributions (NDCs), establish explicit gross carbon dioxide removal targets, and introduce intertemporal instruments such as Carbon Removal Obligations to guarantee the reversal of temperature overshoot.

In summary, climate stabilization will require durable institutions that connect present emissions with future removals across generations.

…

Johannes Bednar et al 2026 Environ. Res. Lett. 21 021002 DOI 10.1088/1748-9326/ae34ca

Gasser, T., Rezai, A., Cheritel, C. et al. Negative emissions to mitigate Earth system risks. Nat Commun (2026). https://doi.org/10.1038/s41467-026-69896-x

[Norrrm]

1. But, but, but that would require effort, money, and inconvenience.

Need more studies and outlaw these two.

??? Not really.

[OKIsItJustMe]

3. "Net Zero" "would require effort, money, and inconvenience"

But, “Net Zero” is not sufficient.

[OKIsItJustMe]

2. Global warming in the pipeline

James E Hansen, Makiko Sato, Leon Simons, Larissa S Nazarenko, Isabelle Sangha, Pushker Kharecha, James C Zachos, Karina von Schuckmann, Norman G Loeb, Matthew B Osman, Qinjian Jin, George Tselioudis, Eunbi Jeong, Andrew Lacis, Reto Ruedy, Gary Russell, Junji Cao, Jing Li, Global warming in the pipeline, Oxford Open Climate Change, Volume 3, Issue 1, 2023, kgad008, https://doi.org/10.1093/oxfclm/kgad008

Eelco J Rohling, Anna S von der Heydt, Editorial on Hansen et al. ‘Global warming in the pipeline’ (this issue), Oxford Open Climate Change, Volume 3, Issue 1, 2023, kgad010, https://doi.org/10.1093/oxfclm/kgad010

[CrispyQ]

4. If we could bring it to zero tomorrow, how many years are already baked in?

I knew the answer once, but forgot.

Reading social media comments on climate change memes is even more depressing than reading the ones on Trump memes. The ignorance & stupidity are astounding.

[OKIsItJustMe]

5. It depends on who you ask

The “hopium” crowd (e.g. Michael Mann) would tell you the warming would stop immediately.

https://michaelmann.net/comments-on-new-article-by-james-hansen/

… our best estimates today are that surface warming stops when carbon emissions stop, i.e.that there is no additional surface warming in the pipeline when emissions reach zero. The notion that there are decades of committed surface warming after emissions reach zero is based on outdated simulations that did not take into account the interactive role of the ocean carbon cycle. While the science on this is more than a decade old, this significant paradigm shift in our understanding of committed warming has still failed to be widely understood or recognized in much of the public discourse over climate science (see this op-ed I co-authored in the Washington Post about that last year). The point is that whether or not the 1.5C target is reachable is a matter of policy, not climate physics, at this point. It's fine for Jim and his colleagues to explore scenarios where we do not act soon enough, and carbon emissions are not lowered adequately to avert specific warming targets such as 1.5C or 2C, but it should be clear that the differences in their conclusions are a result of those policy and behavioral assumptions, not climate physics.

…

https://www.columbia.edu/~jeh1/mailings/2024/Hopium.MarchEmail.2024.03.29.pdf

…

Our paper, Global Warming in the Pipeline, was greeted by a few scientists, among the most active in communication with the public, with denial. Our friend Michael Mann, e.g., with a large public following, refused to concede that global warming is accelerating. We mention Mike because we know that he won’t take this notation personally. Accelerated global warming is the first significant change of global warming rate since 1970. It is important because it confirms the futility of “net zero” hopium that serves as present energy policy and because we are running short of time to avoid passing the point of no return. …

The recent release of a major study confirming that Global Warming is accelerating (I feel) shows who is correct in this disagreement among colleagues.

[CrispyQ]

7. Wow. Hopium is apt.

Apparently, he's never cooked at all.

[NNadir]

6. The paper contains reference 87, which from what I can tell from calling it up is that it involves social sciencey...

...soothsaying based on the usual vague handwaving. Of course, I'm just glancing at it, as I'm busy and I have a low tolerance for handwaving social sciencey stuff.

The paper is here:

Riahi, K. et al. The Shared Socioeconomic Pathways And Their Energy, Land Use, And Greenhouse Gas Emissions Implications: An Overview. Glob. Environ. Change 42, 153–168 (2017).

It's an open source; anyone can read it.

It contains this precious graphic with, um, "storylines."



The caption:

Fig. 1. Schematic illustration of main steps in developing the SSPs, including the narratives, socioeconomic scenario drivers (basic SSP elements), and SSP baseline and mitigation scenarios.

Who wants to bet whether the "storylines" consist of vast stretches of industrialized wilderness for so called "renewable energy," oblivious of the unsustainable material cost, although there does seem to be some musings about land use? (Good luck with that.)

Whether it acknowledges somewhere in the field of references creative engineering using high temperatures, things like reverse Allam cycles, carbonate selective electrodes, process intensification us high nuclear generated temperatures, and straight up [link:Boudouard reaction| Boudoaurd chemistry] is not clear to me. It would probably be a waste of time to wade through internal references.

It doesn't matter really. The paper is from 2017, six years into the adventure in which antinukes and "I'm not an antinuke" antinukes were getting rashes from wedgies as they hoped someone would finally die from radiation exposure at Fukushima to justify their toxic and frankly, deadly, paranoia.

It's almost ten years later. Antinukism is finally, at long last, being relieved of its unjustified acceptance, perhaps way too late, but better way to late than not at all.

The removal and reduction of carbon dioxide from the environment takes energy, massive amounts of energy, energy to overcome the entropy of mixing, and reproduction of all the energy released in putting it there and then some to overcome the entropy term in the Gibbs free energy requirements.

This said, the engineering, while extremely challenging, with the challenges unlikely to be met, is still in the realm of the feasible if not in the realm of the simple.

As I near the end of my life, I am pained to realize what was possible but rejected.

Antinuke gloating over their success at demonizing nuclear energy is gloating over a crime against the future, one the future that has now become the present, and the future of all to follow.

History will not forgive us, nor should it.

Have a wonderful weekend.

[thought crime]

8. Renewable energy is abundant and can be used to power carbon capture systems.

As renewable energy reaches industrial scale and benefits from economy-of-scale and further innovations, it may become the cheapest way to power carbon capture/ CDR.