The problem with the last 30 years mitigation strategy of Emissions Control is not just the corrupt obstruction it still faces, but the fact that, at best, it would eventually halt most anthro-GHG emissions and so, supposedly, stop the problem of global overheating and climate destabilization from getting worse.

But there are two problems with those expectations.
First, stopping the warming from getting worse will do nothing to mitigate whatever level of climate damages are being imposed by that date – and if they are severe enough to disrupt the global economy – via say serial global crop failures, then the crucial investments in new technologies would simply not be made, and society would have entered a vicious spiral of resource damage and decline.

Second, there are eight generic “Major Interactive Feedbacks” [MIFs] that are already accelerating at 1.3C of overheating, where the warming from each one then accelerates all others – after a time lag due to oceanic thermal inertia . However, there are also very numerous “Direct Coupling Mechanisms” where the physical dynamics of one MIF directly impacts another causing its acceleration with little or no delay.
The potential of those mechanisms to form chain reactions between MIFs is perhaps best seen in an example:

– “Marine Overheating” means that the Gulf Stream is delivering massive excess heat to the Arctic Ocean, where it accelerates the melting of sea-ice causing “Albedo Loss” which allows still more solar heat into the ocean, which in turn warms the air mass above it that then moves off over land – where the signature of such warmed air has been recorded as causing accelerated “Permafrost Melt” up to 1500kms from the coast.

Supposing that the essential Emissions Control strategy succeeds in getting near Net Zero by 2050 with a global temp raised by something over 2.0C, it will do nothing to rapidly cool the planet to decelerate the MIFs, which would continue to emit GHGs, and to cause overheating, and to accelerate, thereby offsetting the control of anthro-GHG emissions to an unknown extent.

The strategy of Emissions Control is thus entirely necessary but evidently insufficient to resolve the climate predicament. The first additional option, that of climate engineering by “Carbon Recovery” from excess atmospheric CO2 stocks, is again necessary (and is a basic part of the Net Zero accord) but the scale is so vast for a significant impact which itself then faces a time lag, that within the requisite time frame of several decades it cannot be applied at sufficient scale to be more than just helpful .

The second additional option, that of climate engineering by “Planetary Albedo Restoration” (aka SRM) could serve as the complement to the first two options, in that it would prudently increase albedo to lower the solar energy retention. Such an intervention requires perhaps a decade of extensive research to identify that a technique is both reliably benign and effective. Given that only one candidate technology could be trialled at a time, the present concern should really be the development of a criteria list for the candidates’ selection ranking – For instance, how localised could effective trials be; how quickly an intervention could be halted; the extent of any process or delivery CO2 emissions, the extent of any other pollutants release, etc.

Some scientists and many activists are opposed to such research but, in the last 38 years, I have never heard any credible explanation of how else the planet may be cooled enough to control the untenaby severe climate impacts that we are plainly heading towards, let alone to halt the self-reinforcing MIFs that would otherwise continue global overheating. Since the strategies of Emissions Control & Carbon Recovery are clearly necessary but insufficient, the assembly of a criteria list for technologies for Planetary Albedo Restoration surely ought by now to be a global priority.