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Post by David B. Benson on Jan 15, 2020 18:07:08 GMT 9.5
huon, it was already clear that the so-called Paris goals are out-of-reach for anything but a massive redirection of resources into stopping carbon dioxide emissions and removing excess carbon dioxide from the atmosphere. Even then, there may be a considerable overshoot.
I have no optimism.
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Post by huon on Jan 16, 2020 13:53:28 GMT 9.5
DBB-- Because we have started a new page, I'll copy my previous post, to which you refer: The article points out: "Climate sensitivity [the earth's presumed response to a doubling of atmospheric CO2] has been in the range of 1.5C to 4.5C for more than 30 years. If it is now moving to between 3C and 7C, that would be tremendously dangerous." And as you indicate, DBB, the old numbers are bad enough.
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Post by huon on Jan 16, 2020 15:29:02 GMT 9.5
OTOH, a climate scientist from the University of California, Berkeley has this slightly more encouraging take: "The fact that some of these models are high is interesting, but doesn't necessarily mean we should believe them over other lines of evidence, Hausfather said. "It just reflects the fact that climate sensitivity is this huge remaining source of uncertainty in our climate projections." www.scientificamerican.com/article/these-are-the-biggest-climate-questions-for-the-new-decade (From the article's last section 'Projecting the Future')
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Post by David B. Benson on Jan 16, 2020 15:49:35 GMT 9.5
huon, I use so-called Earth System Climate Sensitivity as measured by paleoclimate extending back to the Pliocene for the current values of carbon dioxide concentration in the atmosphere. The estimate for global temperature is another 2--3 K of warming and a sea level rise of around 25 meters.
The only hope is to lower the current concentration rapidly, although rapidly might mean a century or two.
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Post by David B. Benson on Jan 19, 2020 12:57:07 GMT 9.5
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Post by huon on Jan 22, 2020 14:51:08 GMT 9.5
Great pancake recipe.
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Post by huon on Jan 26, 2020 15:49:28 GMT 9.5
Quit Fossil Fuels to Save Earth, Says 100-Year-Old Theorist Alexander Kwiatkowski Bloomberg (seen on Yahoo Finance) 2020 Jan 20 finance.yahoo.com/news/quit-fossil-fuels-save-earth-050001521.htmlIn this short article, James Lovelock gives his views on, among other topics, climate change, Australia's fires, nuclear power, and the fate of humanity.
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Post by David B. Benson on Jan 28, 2020 14:32:38 GMT 9.5
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Post by David B. Benson on Jan 30, 2020 8:17:13 GMT 9.5
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Post by Barry Woods on Jan 30, 2020 19:04:11 GMT 9.5
Nature journal: We must all — from physical scientists and climate-impact modellers to communicators and policymakers — stop presenting the worst-case scenario as the most likely one www.nature.com/articles/d41586-020-00177-3via BBC www.bbc.co.uk/news/science-environment-51281986Does this mean that climate scientists have been exaggerating the threat? This is more about scientific assumptions added to a communications cock-up. Very few scientists realised that RCP8.5 was originally a 90th percentile outcome, not a most likely or business-as-usual outcome. They assumed too much, when they should perhaps have checked, say the authors of the review. "At the end of the day, scientists have to take responsibility for what they choose as input data, and there should be a degree of due diligence," said Glen Peter, from the CICERO Center for International Climate Research in Norway. "How many of your average climate scientists know the nuances of RCP8.5? It would certainly be interesting to know." The media, taking their steer from scientists, have tended to use the highest impacts when reporting on projections based on emissions scenarios. "That's not to say that these highest-end impacts are impossible to happen, but it is not business-as-usual. And that's the point we're really trying to make in this piece."
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Post by David B. Benson on Jan 31, 2020 15:02:10 GMT 9.5
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Post by huon on Jan 31, 2020 15:32:13 GMT 9.5
Barry Woods-- Thanks so much for your helpful and, indeed, encouraging post. You cover the misuse of RCP8.5 well. And as for guarded optimism, the BBC article concludes:
Is this good news in some ways?
Yes - it show that even the limited attempts to cut carbon that the world has adopted to date are having an impact and the worst emissions scenarios are now longer realistic.
While a world that warms by 3C is a disaster, the progress that's been made should encourage people to aim for higher targets to try to keep the world to 1.5C of warming, which science suggests is a much safer threshold.
[...]
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Post by Barry Woods on Jan 31, 2020 21:17:48 GMT 9.5
Barry Woods-- Thanks so much for your helpful and, indeed, encouraging post. You cover the misuse of RCP8.5 well. And as for guarded optimism, the BBC article concludes: Is this good news in some ways?Yes - it show that even the limited attempts to cut carbon that the world has adopted to date are having an impact and the worst emissions scenarios are no longer realistic. While a world that warms by 3C is a disaster, the progress that's been made should encourage people to aim for higher targets to try to keep the world to 1.5C of warming, which science suggests is a much safer threshold. [...] can't claim the credit.. just quoted the BBC article!!
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Post by David B. Benson on Feb 4, 2020 12:05:20 GMT 9.5
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Post by David B. Benson on Feb 4, 2020 14:29:04 GMT 9.5
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Post by David B. Benson on Feb 4, 2020 16:35:14 GMT 9.5
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Post by David B. Benson on Feb 7, 2020 12:13:44 GMT 9.5
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Post by David B. Benson on Feb 11, 2020 13:44:13 GMT 9.5
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Post by David B. Benson on Feb 12, 2020 11:58:33 GMT 9.5
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Post by mark3 on Feb 13, 2020 0:16:33 GMT 9.5
Thanks for the link. It seems that 8.5 was the test case..... so the estimate needs to be taken with a grain of salt.
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Post by huon on Feb 13, 2020 14:34:45 GMT 9.5
mark3-- I don't readily see what you are referring to. What are the units of 8.5? Where is the number mentioned? Thanks.
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Post by David B. Benson on Feb 13, 2020 14:53:53 GMT 9.5
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Post by David B. Benson on Feb 14, 2020 14:30:55 GMT 9.5
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Post by David B. Benson on Feb 14, 2020 19:10:42 GMT 9.5
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Post by engineerpoet on Feb 15, 2020 19:59:39 GMT 9.5
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Post by David B. Benson on Feb 17, 2020 17:49:51 GMT 9.5
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Post by David B. Benson on Feb 19, 2020 11:52:12 GMT 9.5
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Post by David B. Benson on Feb 19, 2020 12:20:48 GMT 9.5
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Post by Roger Clifton on Feb 19, 2020 18:32:03 GMT 9.5
Warming, acidic oceans may nearly eliminate coral reef habitats by 2100 Perhaps "acidified" might be more accurate. It's a question of being acidic relative to the boundary for this or that species. For example, calcite saturation is a fraction more acidic than aragonite saturation, affecting different genuses/species and different food webs based on them. Beyond that point, the animal struggles to provide an internal environment with the right pH to grow their shells etc. Although the CO2 concentration in the industrial atmosphere and thus in the ocean surface has increased by 45%, the pH has decreased by rather less than -log10(1.45)=-0.16, due to buffering by the pre-existing carbonate content of seawater. The skeletons of coral polyps have continued to grow in the more acidic recent decades, although resulting in decreased density of the coral. The expulsion of the symbiotic algae (bleaching) is due more to the rising temperatures.
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Post by David B. Benson on Feb 20, 2020 22:01:22 GMT 9.5
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