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michael_nielsen's profile
michael_nielsen
michael_nielsen
michael_nielsen
@michael_nielsen

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michael_nielsen

@michael_nielsen

Searching for the numinous. Co-purveyor of https://quantum.country/ 

San Francisco, CA
michaelnielsen.org
Joined July 2008

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    1. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      michael_nielsen Retweeted michael_nielsen

      Curious to contrast with this paper showing evidence that CO2 emissions have peaked (mostly due to fracking):https://twitter.com/michael_nielsen/status/674738150367993856 …

      michael_nielsen added,

      michael_nielsen @michael_nielsen
      Paper in Nature Climate Change (tentatively) suggests global CO2 emissions may be declining http://www.nature.com/articles/nclimate2892.epdf?referrer_access_token=s1awyyC-oO6etR336Cj_HNRgN0jAjWel9jnR3ZoTv0PZ7Wa610RO0dCDFlIIHZ74qcAiRyRLeTjy1w-5IRtPPSUdHbny_NP43wRzYrSEjYc3Yy3cCrW_6kuwy-8K-e8OQuzShps06O73r4wsofA5E-O-EaT7dZSiSRMkiGRrojMwUaRyzOpRy3ekJ1-825iQFi1DD4m81eHFBKN23yCWMP5KNb0xzqXoDieEXqJ8IqROptfJ-r2JDpgA5iSBDIISsx6p41e_yqf5lm2_P31ZPQ%3D%3D&tracking_referrer=www.nytimes.com … pic.twitter.com/RPCzAqPVaM
      3 replies 2 retweets 12 likes
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    2. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      TIL: Nitrous oxide - laughing gas - is an important greenhouse gas. (I wish water vapour was on this graph.)pic.twitter.com/Nk2Zaa1fTR

      2 replies 0 retweets 2 likes
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    3. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      Interesting that methane is apparently levelling out. I don't know why.

      3 replies 0 retweets 2 likes
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    4. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      Also, an estimate I heard in a talk by David Keith: the atmospheric half-life of CO2 is about 1000 years. So without some type of reclamation / sequestration technology, just keeps rising, except over very long time scales.

      3 replies 1 retweet 5 likes
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    5. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      This graph is one of the most fascinating I know of, period (and the error bars are outright the most fascinating I know of). It's the IPCC report's estimate of the radiative forcing due to several sources, with 95% CI's.pic.twitter.com/8H8qMhkO1V

      1 reply 5 retweets 11 likes
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    6. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      A few comments: total estimated forcing is 2.3 Watts per square meter. That's about 0.17% of the solar constant (about 1367 Watts per square meter), a truly tiny (but nonetheless monumental) change!

      2 replies 0 retweets 3 likes
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    7. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      I wish the error bars were discussed a LOT more. A funny thing: in popular writing about climate change, the writer often effectively yells loudly "we KNOW this is going on, anyone who doesn't think so is an anti-science ignoramus." This turns me off.

      2 replies 0 retweets 11 likes
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    8. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      Anyone who discusses a complex subject and turns it into simple slogans, and evinces complete certainty & dismissal of opponents, is someone I have a lot of trouble trusting.

      2 replies 4 retweets 16 likes
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    9. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      Feynman: "In physics the truth is rarely perfectly clear, and that is certainly universally the case in human affairs. Hence, what is not surrounded by uncertainty cannot be the truth.”

      1 reply 10 retweets 30 likes
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    10. michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      In any case, I find those error bars - and the enormous effort the IPCC has put into really understanding them (and great care in reducing them) - absolutely fascinating.

      1 reply 0 retweets 6 likes
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      michael_nielsen‏ @michael_nielsen 9 Sep 2018
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      I'd be curious to know the effect of the Montreal protocol (banning CFCs) on radiative forcing, since - I believe - CFCs are an aerosol reducing radiative forcing. While banning CFCs was a good thing, did it contribute to global warming?

      12:06 PM - 9 Sep 2018
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      • Naveh D. Shetrit Smerity
      4 replies 0 retweets 3 likes
        1. Robbie Andrew‏ @robbie_andrew 10 Sep 2018
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          Replying to @michael_nielsen

          As others have said CFCs are not aerosols, but very potent GHGs. The Montreal Protocol had a huge effect on reducing global emissions of GHGs. E.g. http://www.pnas.org/content/104/12/4814 … Their replacements are also GHGs, but nowhere near as potent.

          0 replies 0 retweets 1 like
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        1. Nick Barnes‏ @nickbarnes 9 Sep 2018
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          Replying to @michael_nielsen

          CFCs are not aerosols. They're powerful GHGs.

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