Hi David,
I said that the level of CO2 had to be reduced if the world was to have
a chance of keeping below 2ºC warming. Perhaps the simplest way to show
this is to use the climate sensitivity calculations of Prof Hansen [1]
and then look at the current level of CO2 equivalent from Prof Prinn
[2]. I admit being shocked when I did the maths!
Hansen says:
"Equilibrium sensitivity 6°C for doubled CO2 is relevant to the case in
which GHG changes are specified. That is appropriate to the
anthropogenic case, provided the GHG amounts are estimated from carbon
cycle models including climate feedbacks such as methane release from
tundra and ocean sediments."
Now while we currently have 400 ppm CO2, the additional greenhouse gases
bring it up to 478 ppm equivalent (CO2e) according to Prinn, so we are
not so far from doubling of CO2e, which would produce 6ºCwarming as
equilibrium temperature according to Hansen. In fact, we are 198 ppm
over the pre-industrial level of 280 ppm.
198 / 280 * 6ºC = 4.24ºC.
This means we've _already_ put enough greenhouse gases into the
atmosphere to produce a _4.24 degrees C_ equilibrium temperature, even
with _no further increase_ in greenhouse gases.
Clearly we will have to suck CO2 out of the atmosphere faster than we
are putting it into the atmosphere! We also have to think about
reducing CO2 because of ocean acidification. Carbon dioxide removal
(CDR) using geoengineering techniques, is essential. This should be
ramped up ASAP.
AMEG proposes a target of CO2 reduction to below 350 ppm in 20 years,
ramping up the CDR continuously over that period. The CDR will
probably require a combination of: (i) CCS for all fossil fuel power
stations, (ii) improved forest management, (iii) improved agricultural
practice such as biochar, and (iv) improved CO2 absorption in the sea
using kelp and photosynthesising algae such as diatoms. The CDR should
be funded by a levy on carbon taken out of the ground, preferably at the
point of extraction thus avoiding the problem of taxation further down
the supply chain.
Cheers,
John
Chair AMEG (Arctic Methane Emergency Group)
[1] http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf
[2]
http://oceans.mit.edu/featured-stories/5-questions-mits-ron-prinn-400-ppm-threshold
--
On 16/03/2014 13:19, Hawkins, Dave wrote:
John,
You say--
the level of CO2 in the atmosphere has to be reduced if the world is to have
any chance of keeping below 2 degrees C warming.
If you are referring to today's level of CO2 in the atmosphere, what paper(s)
can you point to that support this conclusion?
As for the FOE comments about geoengineering, I think it is worth noting that
FOE says it opposes only one form of geoengineering, SRM, and appears to be
primarily concerned about one form of SRM, stratospheric particle injection.
David
Sent from my iPad
On Mar 16, 2014, at 4:50 AM, "John
Nissen"<[email protected]<mailto:[email protected]>> wrote:
Hi all,
FoE says the WG2 report on climate impacts will be published on March 29th and the WG3
report on "pathways to avoid dangerous climate change" will be published on
April 11th.
To quote from the WG3 summary by FoE:
"It is still possible to reduce global carbon pollution fast enough and deep enough
to make 2 degrees of global warming unlikely and provide a small chance of avoiding 1.5
degrees of warming, but only by making far-reaching socio-economic changes."
This is complete twaddle and wishful thinking by people whose solidarity is clearly with the
"egalitarians" (see posting by Dan Kahan on polarities). It is twaddle because the level
of CO2 in the atmosphere has to be reduced if the world is to have any chance of keeping below 2
degrees C warming. There is no way that some vague collection of "socio-economic
changes" can reduce the CO2 in the atmosphere as required. Only geoengineering can do this.
It is also twaddle because the situation in the Arctic is completely ignored.
Best scientific evidence points to a vicious cycle of warming and melting in
the Arctic as albedo is lost. The only way to break this cycle, and halt the
slippery slide into complete Arctic meltdown, is to cool the Arctic.
The sooner that IPCC accepts geoengineering as a logical necessity for both CO2
removal and cooling the Arctic, the sooner that the twin dangers from excess
CO2 and Arctic overheating will be accepted by politicians and society at
large. The talk of geoengineering will make everyone aware that the situation
we find ourselves in is already dangerous - really dangerous.
The only sensible "pathways to avoid dangerous climate change" must involve
geoengineering to remove CO2 and geoengineering to cool the Arctic. The pathway proposed
by WG3 is suicidal lunacy.
Cheers, John
On Sat, Mar 15, 2014 at 12:34 AM, Oscar
Escobar<[email protected]<mailto:[email protected]>> wrote:
IPCC AR5 WG2 report - advance briefing
Intergovernmental Panel on Climate
Change (IPCC)
Fifth Assessment, Working Group 3 report
Questions and answers in advance of publication
http://www.foe.co.uk/sites/default/files/downloads/advance-briefing-ipcc-report-climate-mitigaton-45694.pdf
(Excerpt)
Reasons to be worried
Although the WG3 report will show that the potential to cut carbon pollution
sufficiently to
make 2 degrees warming unlikely exists, it will also illustrate the very
significant
socio-economic changes that are needed to do so. Currently the political will
to make these
changes, for example reducing fossil fuel use or reducing inequalities between
and within
countries, is sorely lacking.
Because of current and past failures to reduce carbon pollution it is not
surprising that the
IPCC has investigated geoengineering options. However, by doing so it
potentially
normalises these approaches alongside energy efficiency, renewables, etc. The
risks of
particularly solar radiation management are very high and this will need to be
made clear.
What are others likely to say?
It is likely that climate deniers will identify the high costs of mitigation
whilst ignoring the
considerable benefits which outweigh the costs.
It is also possible that right-wing think tanks and the media focus on the
potential for
geoengineering as a potentially low cost response to climate change,
particularly regarding
the extremely risky strategy of injection of aerosols into the stratosphere as
a form of solar
radiation management.
Friends of the Earth is opposed to the deployment of solar radiation management.
There is also the danger that some commentators also reject all negative
emissions
technologies in addition to rejecting solar radiation management.
This is simplistic and could create opposition to development of necessary
technologies
to remove carbon pollution from the atmosphere (e.g. air capture of carbon
utilising carbon capture and storage).
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