Re: [geo] Why current negative-emissions strategies remain ‘magical thinking’

2018-02-27 Thread Greg Rau 

Thanks Nature. How about applauding those who are trying to find out whether or 
not CDR is magical thinking, since reaching climate goals without CDR is now 
most certainly a fanciful notion (IPCC: 2013, 2014, 1.5degC report)?Greg

  From: Andrew Lockley <andrew.lock...@gmail.com>
 To: geoengineering <geoengineering@googlegroups.com> 
 Sent: Tuesday, February 27, 2018 2:17 PM
 Subject: [geo] Why current negative-emissions strategies remain ‘magical 
thinking’
   

https://www.nature.com/ articles/d41586-018-02184-x
EDITORIAL   21 FEBRUARY 2018
Why current negative-emissions strategies remain ‘magical thinking’
Work on how rocks draw carbon from the air shows the scale of the challenge.   
   -  
   -  
   - 
 PDF versionSpreading basalt rock on farmland has been suggested as a way to 
soak up carbon pollution from the atmosphere.Credit: Hartmut 
Schmidt/imageBROKER/AlamyDecarbonization of the world’s economy would bring 
colossal disruption of the status quo. It’s a desire to avoid that change — 
political, financial and otherwise — that drives many of the climate sceptics. 
Still, as this journal has noted numerous times, it’s clear that many 
policymakers who argue that emissions must be curbed, and fast, don’t seem to 
appreciate the scale of what’s required.According to the Intergovernmental 
Panel on Climate Change (IPCC), carbon emissions must peak in the next couple 
of decades and then fall steeply for the world to avoid a 2 °C rise. A peak in 
emissions seems possible given that the annual rise in carbon pollution stalled 
between 2014 and 2016, but it’s the projected decline that gives climate 
scientists nightmares.The 2015 Paris agreement gave politicians an answer: 
negative emissions. Technology to reduce the amount of carbon already in the 
atmosphere will buy society valuable time. The agreement went as far as arguing 
that incorporating one such technology — bioenergy with carbon capture and 
storage (BECCS) — could even see the global temperature increase kept to 1.5 
°C.What would negative emissions look like? A Perspective this week in Nature 
Plants offers another glimpse, and it’s not pretty (D. J. Beerling et al. 
Nature Plantshttp://dx.doi.org/10. 1038/s41477-018-0108-y; 2018). The review 
focuses on the idea of enhanced weathering, which aims to exploit how many 
rocks react with carbon dioxide and water to form alkaline solutions that, over 
time, find their way into the sea. It’s one of a number of proposed 
negative-emissions technologies.In theory, enhanced weathering could lock up 
significant amounts of atmospheric carbon in the deep ocean. But the effort 
required is astounding. The article estimates that grinding up 10–50 tonnes of 
basalt rock and applying it to each of some 70 million hectares — an area about 
the size of Texas — of US agricultural land every year would soak up 13% of the 
annual global emissions from agriculture. That still leaves an awful lot of 
carbon up there, even after all the quarrying, grinding, transporting and 
spreading.It’s not hard to see why many climate scientists have dismissed the 
near-impossible scale of required negative emissions as “magical thinking”. Or 
why the European Academies’ Science Advisory Council said in a report this 
month: “Negative emission technologies may have a useful role to play but, on 
the basis of current information, not at the levels required to compensate for 
inadequate mitigation measures.”The IPCC is now working on a report on 
strategies to keep warming to under 1.5 °C, which is due to be published later 
this year. By necessity, those strategies will lean heavily on negative 
emissions. Scientists must continue to spell out to policymakers the harsh 
reality of what this would involve, and in the strongest possible terms.Nature 
554, 404 (2018)doi: 10.1038/d41586-018-02184-x-- 
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[geo] Why current negative-emissions strategies remain ‘magical thinking’

2018-02-27 Thread Andrew Lockley 
https://www.nature.com/articles/d41586-018-02184-x

EDITORIAL
 21 FEBRUARY 2018
Why current negative-emissions strategies remain ‘magical thinking’
Work on how rocks draw carbon from the air shows the scale of the challenge.

   -
   


   -
   


   -
   


 PDF version

[image: Basalt quarry]

Spreading basalt rock on farmland has been suggested as a way to soak up
carbon pollution from the atmosphere.Credit: Hartmut
Schmidt/imageBROKER/Alamy

Decarbonization of the world’s economy would bring colossal disruption of
the status quo. It’s a desire to avoid that change — political, financial
and otherwise — that drives many of the climate sceptics. Still, as this
journal has noted numerous times, it’s clear that many policymakers who
argue that emissions must be curbed, and fast, don’t seem to appreciate the
scale of what’s required.

According to the Intergovernmental Panel on Climate Change (IPCC), carbon
emissions must peak in the next couple of decades and then fall steeply for
the world to avoid a 2 °C rise. A peak in emissions seems possible given
that the annual rise in carbon pollution stalled between 2014 and 2016, but
it’s the projected decline that gives climate scientists nightmares.

The 2015 Paris agreement gave politicians an answer: negative emissions.
Technology to reduce the amount of carbon already in the atmosphere will
buy society valuable time. The agreement went as far as arguing that
incorporating one such technology — bioenergy with carbon capture and
storage (BECCS) — could even see the global temperature increase kept to
1.5 °C.

What would negative emissions look like? A Perspective this week in *Nature
Plants* offers another glimpse, and it’s not pretty (D. J. Beerling *et al.
Nature Plants*http://dx.doi.org/10.1038/s41477-018-0108-y; 2018
). The review focuses on the
idea of enhanced weathering, which aims to exploit how many rocks react
with carbon dioxide and water to form alkaline solutions that, over time,
find their way into the sea. It’s one of a number of proposed
negative-emissions technologies.

In theory, enhanced weathering could lock up significant amounts of
atmospheric carbon in the deep ocean. But the effort required is
astounding. The article estimates that grinding up 10–50 tonnes of basalt
rock and applying it to each of some 70 million hectares — an area about
the size of Texas — of US agricultural land every year would soak up 13% of
the annual global emissions from agriculture. That still leaves an awful
lot of carbon up there, even after all the quarrying, grinding,
transporting and spreading.

It’s not hard to see why many climate scientists have dismissed the
near-impossible scale of required negative emissions as “magical thinking”.
Or why the European Academies’ Science Advisory Council said in a report
this month: “Negative emission technologies may have a useful role to play
but, on the basis of current information, not at the levels required to
compensate for inadequate mitigation measures.”

The IPCC is now working on a report on strategies to keep warming to under
1.5 °C, which is due to be published later this year. By necessity, those
strategies will lean heavily on negative emissions. Scientists must
continue to spell out to policymakers the harsh reality of what this would
involve, and in the strongest possible terms.

Nature 554, 404 (2018)
doi: 10.1038/d41586-018-02184-x

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