This is really the key graphic that I think tells the story best: it's the amount of projected warming for each year's analysis

Things really did get better after the Paris Agreement. But it has stagnated post-covid, and we could backslide......

climateactiontracker.org/publications...

Nous avons publié une réponse dans Frontiers pour corriger des déclarations trompeuses dans l'article de Siegert et al, en utilisant des graphiques tirés d'articles cités par Siegert et al. Et nous avons tentés d'apporter un peu de nuances dans leurs propos. www.frontiersin.org/journals/ear...

These climate risks could be reduced with SRM, which is why it is worth investigating, and why I strongly object to the claim that "research into these techniques would not be an effective use of limited time and resources".

However, given that net zero only stops temperature rise (and deep ocean temperatures continue to rise thereafter), we might be facing unacceptably high climate risks even under ambitious mitigation scenarios.

I certainly understand objections to geoengineering. It could increase geopolitical tensions, could be used as an excuse to delay mitigation, and it introduces new risks such as termination shock.

We then rebalance their account of the polar impacts of stratospheric aerosol injection to include potential benefits as well as risks.

Using 2 figures from articles cited by Siegert et al, we challenge 2 of their statements on the effect of stratospheric aerosol injection (SAI) on the Arctic: 1/ that SAI is ineffective in the polar winter and 2/ that polar injection locations would be needed to produce an impact in polar regions.

There is no tas for the concentration-driven mode after 2100?

Sounds good! I'll draft something up and get in touch.

It's for sure messy, especially with the increasing interest from private actors. But I don't think we can, at this point, avoid careful consideration of all our options.

Getting to net zero only stops the temperature from increasing, but doesn't bring it back down. At the moment, CDR is slow and expensive. And sea level rise continues after net zero as that depends on deep ocean temperatures which lag behind surface temperatures.

The concern which motivates my research into SRM is that even under very ambitious mitigation scenarios, we might face devastating impacts from climate change (sea level rise, heat waves, AMOC collapse, etc). SRM is the only method that can rapidly reduce temperatures.

Glad to see the left engaging on this, great podcast! It's true that early climate modelling of SRM focused on high emissions scenarios. However, current SRM modelling uses "middle-of-the-road" scenarios (SSP2-4.5) which are close to projected emissions.

... it is attracting growing interest, including from private actors.

In this report, we objectively summarise the many risks and potential benefits of the two most prominent SRM methods (stratospheric aerosol injection and marine cloud brightening).