Huh? We can implement policies to overcome the Tragedy of the Commons, as we do for CFCs, asbestos & 1000s of other things. If we let everyone do what they want, we certainly will fail. We need leadership to implement policies that get everyone to support survival.

All you are saying is that we will continue to not take climate actions seriously & we will let FF companies do as they please. If we continue to choose to fail, we will. But serious climate action includes CDR, SRM & phase out of FF.

Actually, SRM *decreases* emissions because warming causes emissions (as a feedback). So using SRM not only stops temperature overshoot, it reduces the amount of CDR needed to get back to a safe temperature.
youtube.com/live/NfCATLY...

Paywalled

I’d like to interview you about SLR on Climate Chat!

Do you use IPCC models for future climate or measured CERES data for EEI and implied ECS? I assume if we hit 2°C in the 2030s instead of 2050, that impacts SLR.

I’m interviewing Eric Rignot this Sunday on Climate Chat about accelerating melting of WAIS. He might have something to add to this discussion.

If we reduce CO2 emissions by 50 GT/year ("net-zero") that only reduces the increase in cumulative emissions by 1.9%/year (50 Gt / 2600 Gt). In other words, CO2 is already too high & *only* reducing emissions, at this point, is not enough to maintain a safe climate for our children.

We can have massive CO2 removal if we (governments) are willing to pay for it. It won't happen via voluntary removal credits.

If we continue to choose to fail, we will. If we choose to succeed, the plan will include emissions phase out, CDR, and SRM.

Also see Hansen's 2007 letter on Scientific Reticence and SLR where he discusses how & why the scientific process (& scientists) underestimates SLR:
www.giss.nasa.gov/pubs/docs/20...

SLR might not get to multimeter this century but we should assume the worst & hope for the best.

James Hansen disagrees with you about multi-meter SLR.

As for AMOC collapse, we could pass the tipping point around 2050 & "full collapse" (which is not total shutdown) happens 30~100 years later. But even 50% slowdown (we're at 15~20% now) would have major impacts on the climate & SLR.

But that does not consider possible (likely?) AMOC collapse that would keep warm water near Antartica & lead to "multi-meter" (10+ feet) SLR by 2100. Plus an extra 2~3 feet in NJ due to AMOC "slosh back".

Plan for the worst and hope for the best.

We should replace "accidental" aerosol cooling in the lower atmosphere (that kills 8M people/year) with purposeful stratospheric aerosol cooling that requires 95% less aerosols & is 1000X safer for human health.
www.hsph.harvard.edu/c-change/new...

If @drjamesehansen.bsky.social at all. (2025, mainly based on NASA CERES observations) is correct about the very strong shipping SOx forcing, the climate is more sensitive to anthropogenic forcings (incl both GHGs and aerosols).

Which e.g. means we need much faster mitigation and adaptation.

We know why!

I'm not sure a political revolution is needed if an imminent threat is felt. After 9/11, we took all kinds of action (including irresponsible ones) without a political revolution.

If we're being rational (we're not), we would realize that we are facing an imminent threat now!

Governance of emissions is difficult because humans don't care about the future & things seem "normal" now. SRM will be governed in a world being immediately threatened. Our "threat indicators" will finally be triggered. At that point, only SRM will provide relief in a meaningful timeframe.

Link to @andrewdessler.com paper that debunks the Department of Energy's climate denial report:
essopenarchive.org/users/260056...

This, of course, will *reduce* temperature increases (at least in the short run)!

The IMO's 2020 reduction in sulfur emissions led to the dramatic increase in temperatures since 2023!