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On 2016-11-06 01:50, spike wrote:<br>
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<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p>My
intuition is that somehow the overall impact would need to
be cooling in the short run, net warming in the long run.
Reasoning: soot in the upper atmosphere (the remains of USA
and Russia) would decrease albedo so in the long run would
absorb more solar energy while blocking solar energy to the
surface in the short run.</span></p>
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</blockquote>
The issue is that the stratosphere is efficient at re-radiating
higher temperatures to space, while the troposphere isn't. Make the
stratosphere black and it heats up (which contributes to the
stability of the nuclear winter), but most of the absorbed heat is
emitted into space rather than down to the ground. <br>
<br>
<blockquote cite="mid:022b01d237d0$323476b0$969d6410$@att.net"
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<p class="MsoNormal"><span
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<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">I
am looking into the bovine models. We are told that cow
farts are introducing huge amounts of methane into the
atmosphere, and that corn-fed cows create way more methane
than grass-fed. My intuition drives me to conclude that we
could create enormous vats in which we mimic whatever
reaction is taking place inside cows, convert corn to
methane directly, use that to greenhouse our way over the
cold decade after we nuke ourselves.</span></p>
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<br>
Unfortunately, methane has GWP of merely 86 times CO2. So you would
need to boost the methane content like 1/86 of the CO2 that would
counteract the nuclear winter. We are talking about 10+ degrees
here, so we would need something like an increase of methane
emissions by a factor of 12+. So we are talking about 360 million
tons per year or more.<br>
<br>
I think ameliorating nuclear (or asteroid, or supervolcano) winter
using greenhouse gas is not totally crazy. Many fluorocarbons have
much greater greenhouse potential (carbon tetraflouride has 50,000!)
You would need to manufacture and release them in the aftermath of a
nuclear war which is tough, and I can see some serious issues about
both risks of having stores (if there was an accidental or
deliberate release they would do bad things to a normal climate).
There are also the problem with lack of light and ozone layer, which
would be bad for agriculture even if it was not freezing. But these
issues can be analysed and worked out, and I think they should be
checked just in case.<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University</pre>
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