SRM extract of IPCC AR6 WG II Final Draft Report

[Ron Baiman]

Colleagues,

This extract from Grant Gower may be of interest.

Best,

Ron

I extracted Chapter 16 from the 3676 pages of IPCC's Working Group II report that was released on 28 February.

Thanks go to Suzanne for alerting me to this document's existence through a report from C2G, the Carnegie Climate Governance Initiative, which is also attached.

C2G's preamble states:

 

"The IPCC AR6 Working Group II (WG-II) report published on 28th February 2022 assesses the vulnerability of socio-economic and natural systems to climate change, the consequences of climate change and options for adapting to it. This briefing summarizes how solar radiation modification (SRM) is addressed in the report (Part I) and identifies some key policy implications developed by C2G (Part II). SRM is expected to be further addressed in the forthcoming WG-III (expected April 2022). The final AR6 Synthesis Report, which will cover the findings of all three Working Group reports, is expected in September 2022." 

Note that the data from which the Report's findings are based were published in reviewed scientific literature as of 1 September 2021!

These data will be one year old by the time the Synthesis Report will be issued.

Be well!

Grant

[Ron Baiman]

Thank you John. Good points!

Sent from my iPhone

On Mar 14, 2022, at 10:08 AM, John Nissen <johnnis...@gmail.com> wrote:



Hi everyone, and thanks, Ron.

 

I suppose we should have expected the IPCC to denigrate SRM, because it is a threat to their strategy: emissions reduction and adapting to inevitable climate change.  But we would have hoped for a balanced assessment of risks and benefits, with and without SRM.  Instead they totally ignore the main purpose of SRM: emergency short-term cooling (i) to quickly reverse the trend towards more extreme weather and climate; and (ii) to avoid tipping points, especially in the Arctic, which could lead to abrupt and potentially catastrophic climate change and/or sea level rise.  We would have hoped for more sympathy to SRM: given the rapidly deteriorating situation with mega-droughts and mega-floods; given the dire warnings (e.g. by Hansen) that 1.5C could be exceeded within a decade; given the existential risk to small island states and low lying countries; and given the many declarations of climate emergency across the world.

 

Their general statement below overplays what can be done through the current strategy of emissions reduction plus CDR and undermines the crucial role that SRM has to play if climate change is to be reversed and tipping point catastrophes averted:

 

There is high agreement in the literature that, for addressing climate change risks, SRM cannot be the main policy response to climate change and is, at best, a supplement to achieving sustained net zero or net negative CO2 emission levels globally [references include MacMartin et al, 2018].  SRM contrasts with climate change mitigation activities, such as emissions reductions and CDR, as it introduces a ‘mask’ to the climate change problem, by altering the Earth’s radiation budget, rather than attempting to address the root cause of the problem, which is the increase in GHGs in the atmosphere. 

 

The table of impacts they present is confusing because they imply impacts are negative whereas they may be positive, e.g. plants would generally benefit from the (very slightly) more diffuse sunlight with SAI, and the changes (a very small reduction) in surface ozone and UV radiation would be beneficial to human health.  The benefits of simple cooling are omitted from the table altogether – yet they correspond precisely to the huge damage done by global warming to date!

 

At least we can understand more clearly the political barrier we are fighting against in our bid for a better future for our children and grand-children.

BTW, don't forget the PRAG meeting is in just under five hours' time [1].

Cheers, John

 

P.S.  Note that definitions have been changed from the normally accepted:

• SRM is Solar Radiation Modification instead of Management
• SAI is Stratospheric Aerosol Interventions (note plural) instead of Injection

Surface albedo modification is split into Ground-Based Albedo Modification (GBAM) and Ocean Albedo Change (OAC).  And Cirrus Cloud Thinning is included under SRM, noting that it is to do with outgoing thermal radiation rather than insolation; some people are using the term Earth Radiation Management (ERM) for this.

[1] Zoom link for Planetary Restoration Action Group Meeting 8pm Monday 14th March UK time. 

https://us02web.zoom.us/j/87270131801?pwd=OFZvMkRVVnRQUUhpUzJBM0kwZnFjUT09

 

The US is now switching to summer time so this is 1pm in California. 7am Tuesday AEDT.

 

--
You received this message because you are subscribed to the Google Groups "NOAC Meetings" group.
To unsubscribe from this group and stop receiving emails from it, send an email to noac-meeting...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/noac-meetings/CAPhUB9AxXiqZKE-8JCcsH3GXfy-%3DkiSQ47sMCAmuSouJ7nCfkA%40mail.gmail.com.