Re: [geo] Estimating global agricultural effects of geoengineering using volcanic eruptions

[Andrew Lockley]

I really think this paper needs a rebuttal. I'm happy to work on it, even
if that's just (uncredited) coordination. It's a disastrously bad situation
when this kind of sloppy science achieves global prominence.

A

On Fri, 10 Aug 2018, 13:28 Douglas MacMartin,  wrote:

> And to add to Anthony,
>
> -Data is too limited to do what they want (really only one major
> volcanic eruption, which is confounded by an El Nino, which they try to
> subtract off of the signal by assuming that every El Nino has an identical
> effect)
>
> -The solar dimming and many precipitation changes from an
> eruption are fast, but the temperature effect is not, so a sustained
> aerosol layer will have different effects
>
>
>
> I and many other people told the authors about these challenges before
> they even wrote the paper, and suggested that they be more cautious in
> their description.
>
>
>
> Reading the paper won’t help, because they don’t really tell the reader
> all of the problems with the approach; the problems aren’t in the
> methodology per se, they are in the interpretation of the results.
>
>
>
> doug
>
>
>
> *From:* geoengineering@googlegroups.com [mailto:
> geoengineering@googlegroups.com] *On Behalf Of *Andrew Lockley
> *Sent:* Thursday, August 09, 2018 5:44 PM
> *To:* RAU greg 
> *Cc:* geoengineering 
> *Subject:* Re: [geo] Estimating global agricultural effects of
> geoengineering using volcanic eruptions
>
>
>
> Really good critique of this paper from Ant Jones on this thread
> https://twitter.com/antcjones/status/1027474182681108480?s=19
>
>
>
> There's a series of various, severe shortcomings (adaptation deficit, no
> CO2 fertilisation, no hydro cycle transients, etc.). Pretty surprising to
> hear this level of criticism on a regular paper, let alone in Nature.
>
>
>
> Media coverage was an absolute car crash - with UK left wing newspapers
> Independent and Guardian giving coverage that was pretty much the opposite
> of the paper's (disputed) findings (no net effect became negative effect).
>
>
>
> This very much backs up my arguments on pay walls - even I've not seen the
> full paper. The public has little hope of getting to the truth on this.
>
>
>
> Andrew Lockley
>
>
>
> On Thu, 9 Aug 2018, 17:15 Greg Rau,  wrote:
>
> Further discussion:
>
>
> https://www.washingtonpost.com/news/speaking-of-science/wp/2018/08/08/this-climate-change-hack-would-reflect-more-sunlight-not-such-a-bright-idea-study-says/?noredirect=on_term=.ca7f63bc40ba
>
>
>
>
>
>
> --
>
> *From:* Andrew Lockley 
> *To:* geoengineering 
> *Sent:* Thursday, August 9, 2018 12:44 AM
> *Subject:* [geo] Estimating global agricultural effects of geoengineering
> using volcanic eruptions
>
>
>
> Poster's note: can't read full paper but I'm interested to see how much
> adaptation it assumed
>
>
> https://www.nature.com/articles/s41586-018-0417-3
>
>
>
> [image: Nature] 
>
> Letter | Published: 08 August 2018
> 
> Estimating global agricultural effects of geoengineering using volcanic
> eruptions
>
> ·Jonathan Proctor
> ,
>
> ·Solomon Hsiang
> ,
>
> ·[…]
>
> ·Wolfram Schlenker
> 
>
> *Nature* (2018) | Download Citation
> 
> Abstract
>
> Solar radiation management is increasingly considered to be an option for
> managing global temperatures1
> ,2
> , yet the
> economic effects of ameliorating climatic changes by scattering sunlight
> back to space remain largely unknown3
> . Although
> solar radiation management may increase crop yields by reducing heat stress
> 4 , the
> effects of concomitant changes in available sunlight have never been
> empirically estimated. Here we use the volcanic eruptions that inspired
> modern solar radiation management proposals as natural experiments to
> provide the first estimates, to our knowledge, of how the stratospheric
> sulfate aerosols created by the eruptions of El Chichón and Mount Pinatubo
> altered the quantity and quality of global sunlight, and how these changes
> in sunlight affected global crop yields. We find that the sunlight-mediated
> effect of stratospheric sulfate aerosols on yields is negative for both C4
> (maize) and C3 (soy, rice and wheat) crops. Applying our yield model to a
> solar radiation management scenario based on stratospheric sulfate
> aerosols, we find that projected mid-twenty-first century damages due to
> scattering sunlight caused by solar radiation management 

RE: [geo] Estimating global agricultural effects of geoengineering using volcanic eruptions

[Douglas MacMartin]

And to add to Anthony,

-Data is too limited to do what they want (really only one major 
volcanic eruption, which is confounded by an El Nino, which they try to 
subtract off of the signal by assuming that every El Nino has an identical 
effect)

-The solar dimming and many precipitation changes from an eruption are 
fast, but the temperature effect is not, so a sustained aerosol layer will have 
different effects


I and many other people told the authors about these challenges before they 
even wrote the paper, and suggested that they be more cautious in their 
description.

Reading the paper won’t help, because they don’t really tell the reader all of 
the problems with the approach; the problems aren’t in the methodology per se, 
they are in the interpretation of the results.

doug

From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of Andrew Lockley
Sent: Thursday, August 09, 2018 5:44 PM
To: RAU greg 
Cc: geoengineering 
Subject: Re: [geo] Estimating global agricultural effects of geoengineering 
using volcanic eruptions

Really good critique of this paper from Ant Jones on this thread 
https://twitter.com/antcjones/status/1027474182681108480?s=19

There's a series of various, severe shortcomings (adaptation deficit, no CO2 
fertilisation, no hydro cycle transients, etc.). Pretty surprising to hear this 
level of criticism on a regular paper, let alone in Nature.

Media coverage was an absolute car crash - with UK left wing newspapers 
Independent and Guardian giving coverage that was pretty much the opposite of 
the paper's (disputed) findings (no net effect became negative effect).

This very much backs up my arguments on pay walls - even I've not seen the full 
paper. The public has little hope of getting to the truth on this.

Andrew Lockley

On Thu, 9 Aug 2018, 17:15 Greg Rau, 
mailto:gh...@sbcglobal.net>> wrote:
Further discussion:
https://www.washingtonpost.com/news/speaking-of-science/wp/2018/08/08/this-climate-change-hack-would-reflect-more-sunlight-not-such-a-bright-idea-study-says/?noredirect=on_term=.ca7f63bc40ba




From: Andrew Lockley mailto:andrew.lock...@gmail.com>>
To: geoengineering 
mailto:geoengineering@googlegroups.com>>
Sent: Thursday, August 9, 2018 12:44 AM
Subject: [geo] Estimating global agricultural effects of geoengineering using 
volcanic eruptions

Poster's note: can't read full paper but I'm interested to see how much 
adaptation it assumed

https://www.nature.com/articles/s41586-018-0417-3


[Nature]
Letter | Published: 08 August 
2018
Estimating global agricultural effects of geoengineering using volcanic 
eruptions
·Jonathan 
Proctor,
·Solomon 
Hsiang,
·[…]
·Wolfram 
Schlenker
Nature (2018) | Download 
Citation
Abstract
Solar radiation management is increasingly considered to be an option for 
managing global 
temperatures1,2,
 yet the economic effects of ameliorating climatic changes by scattering 
sunlight back to space remain largely 
unknown3. Although 
solar radiation management may increase crop yields by reducing heat 
stress4, the effects 
of concomitant changes in available sunlight have never been empirically 
estimated. Here we use the volcanic eruptions that inspired modern solar 
radiation management proposals as natural experiments to provide the first 
estimates, to our knowledge, of how the stratospheric sulfate aerosols created 
by the eruptions of El Chichón and Mount Pinatubo altered the quantity and 
quality of global sunlight, and how these changes in sunlight affected global 
crop yields. We find that the sunlight-mediated effect of stratospheric sulfate 
aerosols on yields is negative for both C4 (maize) and C3 (soy, rice and wheat) 
crops. Applying our yield model to a solar radiation management scenario based 
on stratospheric sulfate aerosols, we find that projected mid-twenty-first 
century damages due to scattering sunlight caused by solar radiation management 
are roughly equal in magnitude to benefits from cooling. This suggests that 
solar radiation management—if deployed using stratospheric sulfate aerosols 
similar to those emitted by the volcanic eruptions it seeks to mimic—would, on 
net, attenuate little of the global agricultural damage from climate change. 
Our approach could be extended to study the effects of solar radiation 
management on other global