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Comment on Hansen’s backfire by David L. Hagen

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<b>Ignored Low Climate Sensitivity?</b> While Hanson appeals to the IPCC, it appears he ignores recent evidence of low climate sensitivity. He does not appear to address the consequent sever Type B uncertainty bias in his models. See: <a href="http://naturalresources.house.gov/uploadedfiles/michaelstestimony.pdf" rel="nofollow"> PATRICK J. MICHAELS </a>, Statement, HEARING ON AN ANALYSIS OF THE OBAMA ADMINISTRATION’S SOCIAL COST OF CARBON, COMMITTEE ON NAURAL RESOURCES, US House, July 22,2015 <blockquote>In May 2013, the Interagency Working Group produced an updated SCC value by incorporating revisions to the underlying three Integrated Assessment Models (IAMs) used by the IWG in its initial 2010 SCC determination. But, at that time, the IWG did not update the equilibrium climate sensitivity (ECS) employed in the IAMs. This was not done, despite there having been, <b>since January 1, 2011, at least 14 new studies and 20 experiments (involving more than 45 researchers) examining the ECS, each lowering the best estimate and tightening the error distribution about that estimate. </b> Whereas the IWG ECS distribution has a median value of 3.0°C and 5th and 95th percentile values of 1.72°C and 7.14°C, respectively, the corresponding values averaged from the recent scientific literature are 2.0°C (median), 1.1°C (5th percentile), and 3.5°C (95th percentile). .. . . In other words, the IWG2010 turned towards surveys of the scientific literature to determine its assessment of an appropriate value for the 95th percentile of the ECS distribution. Now, more than five years hence, the scientific literature tells a completely different story. Instead of a 95th percentile value of 7.14°C, as used by the IWG2010, <b>a survey of the recent scientific literature suggests a value of 3.5°C—more than 50% lower. </b> And this is very significant and important difference because the high end of the ECS distribution has a large impact on the SCC determination—a fact frequently commented on by the IWG2010. </blockquote>

Comment on Hansen’s backfire by -1=e^iπ

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IPCC projections are consistent with our understanding of the time scale of the ice-albedo feedback and equilibrium change in sea level rise due to paleo climate data.

The time scale of decay towards equilibrium of the ice-albedo feedback is on the order of a few hundred years. This can be seen in the output of GCMs and one can also see why this is roughly the case since the time scale of decay should be approximately the amount of time it takes to melt a square meter of glacier ice with the forcing change that would result from a loss of a square meter of ice in polar regions.

The ice sheets in Greenland and Antarctica are approximately 2.5 km thick. The density of ice is approximately 917 kg/m^3. The enthalpy of melting ice is 333.55 kJ/kg. Annual average insolation at a pole is roughly 173 W/m^2. Ice albedo for these ice sheets is about 0.7. Tundra albedo is roughly 0.2. The mean cloudiness of Earth is about 0.5. Therefore, the time scale of decay of the ice-albedo feedback is approximately 2.5km*917kg/m^3*333.55kJ/kg / (0.5*(0.7-0.2)*173W/m^2) = 560 years.

From Paleoclimate data we know that the Eemian was approximately 1.5 C warmer and had sea levels were ~ 4.5 m higher. So this suggests that the equilibrium change in sea level is approximately 3 m / C. If the sea level response to a change in temperature is an exponential decay to equilibrium then given that the 0.8 C temperature increase since pre-industrial times occurred over a relatively short time period relative to time scale of the ice-albedo feedback, the expected rate of sea level rise should be approximately 3 m / C * 0.8 C / 560 y = 43 cm per century. Which is consistent with the half meter per century prediction by the IPCC.

Hansen’s ‘predictions’ of sea level rise, which assume a constant doubling time are completely unphysical. The rate of change of radiative forcing doesn’t have a constant doubling time so why would sea level rise? Radiative forcing is increasing roughly quadratically, so a quadratic fit to recent sea level data to make predictions seems far more reasonable. And not only that, but Hansen isn’t even fitting his bad model of constant doubling time to the data. He is just choosing arbitrary values as going ‘well if sea level rise has an arbitrary doubling time of X then we will get a sea level rise of Y’.

If I obtain sea level data from here (http://www.cmar.csiro.au/sealevel/sl_data_cmar.html) and fit a quadratic trend, it suggests that sea levels will rise by 31 cm from 2015 to 2115.

To me it seems that James Hansen is completely disrespecting the scientific method, using unphysical assumptions to get the conclusion he wants, and completely neglecting proper statistical analysis.

Comment on Week in review – science edition by Jim D

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There’s a good physics reasons why GRACE doesn’t see sea-ice changes. Clue: the density isn’t much different from water and it displaces its own mass. GRACE shows you what matters which is how much land ice goes to sea level elsewhere. Maybe that aspect doesn’t matter to you, but most people are concerned. Hansen has a whole paper on this that is receiving attention.

Comment on Hansen’s backfire by Jim D

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If you want to do it that way, you can take your loss rate as linear, so in a century you have lost (100/560=)18% of your ice. Hansen’s 5 m only requires a 7% loss.

Comment on Hansen’s backfire by fizzymagic

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<i>You guys just won’t give it up. Lol. It’s weird. </i> Might seem weird to you because it is focused on integrity, but it doesn't seem weird to an actual scientist. I have no problem with the paper; I have a <i>big</i> problem with the press releases on the paper. Those press releases contained predictions not found in the paper, but since Hansen was involved in those press releases, he bears responsibility. Your attempt to distract from the issue by debating only what is in the paper, pretending that there was no extra-paper press release, is both disingenuous and scientifically dishonest, and it is those behaviors I find most troubling.

Comment on Eco – (post) modernism by Vaughan Pratt

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@DS: Given law of entropy is true then entropy was never lower than at the instant of the big bang. Then from whence came all the order in the universe?

A fair question (for a change).

Andrew Grant gives a clear answer in this week’s Science News at

https://www.sciencenews.org/article/arrow-time

At the big bang the universe was highly ordered. Assuming its energy Q was the same then as now, and that order increases with decreasing entropy, for a really high degree of orderliness thermodynamics would demand a really high temperature.

As the universe expanded it became less ordered, with the colder parts being less ordered. Any heat warming the colder parts back up gave them a little order back, like recharging their battery.

In Earth’s case order in the form of thermal energy comes from the Sun. That energy can be put to use to create order.

Calculation consumes energy to create information, which is why computers necessarily generate heat in the course of calculating. Likewise with the 1.5 l of human brain, which generates some 100 watts in order to operate.

Gravity is another source of order. Water sprayed into a bucket is a disordered collection of droplets that gravity pulls down into a more ordered body of water.

For more read Grant’s article. Yet more can be seen at Barbour et al’s article at http://arxiv.org/abs/1409.0917

Comment on Eco – (post) modernism by Vaughan Pratt

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@DM: <I> I am pro-life.</I> Does that make you opposed to choice, Don?

Comment on Hansen’s backfire by JCH

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I find people who go by press conferences and bad books and reporters more than deeply disturbing.

As much as.


Comment on Hansen’s backfire by mosomoso

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An internet mate of mine, Spangled Drongo, old yachtsman, compiled a list of biggest decadal sea level rises going by Jevrejeva et al [2008]. (SD spent a lot of his life under sail in highly competitive conditions. He’s someone with a compulsive eye on the sea, alert to every change, long or short term.) It’s only a list of decadal rises based on the one study, but worth a bo-peep:

1804-1813 12.75
1803-1812 10.67
1728-1737 10.30
1789-1798 8.38
1842-1851 7.87
1858-1867 7.82
1788-1797 7.72
1861-1870 7.66
1808-1817 7.58
1785-1794 7.18
And here are the top ten decades since “CAGW”.
1989-1998 4.66
1990-1999 3.95
1991-2000 3.86
1956-1965 3.79
1986-1995 3.78
1974-1983 3.71
1952-1961 3.65
1993-2002 3.63
1988-1997 3.44
1975-1984 3.30

You can see Hansen’s problem, even with swampy old Manhattan – and even after some doofus drastically narrowed the mouth of the Hudson in the 80s to make more real estate.

Comment on Hansen’s backfire by Hans Erren

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Schneider made a clear distinction beween “honest” science, which shows all the caveats, and “effective” “science” which “gets load of media attention”.

Effective “science” is not honest, you can’t be both “effective” and “honest” at the same time.

On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but — which means that we must include all the doubts, the caveats, the ifs, ands, and buts. On the other hand:

There is no other hand, the other hand is not science.

Comment on Eco – (post) modernism by Vaughan Pratt

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@anng: However, humans develop a conservative mentality with experience.

Experience can be used to argue either way.

The further back your experience goes, the more you are inclined to rely on what you’ve learned on average from that experience. So a thousand years of experience equips you to emulate what your ancestors 500 years ago used to do. That makes you a conservative.

But more experience equips you with more ability to turn on a dime to respond to change. That makes you a progressive.

Whatever it is that separates conservatives from progressives, it’s not experience.

Comment on Hansen’s backfire by La predicción de Hansen de 5 metros de subida del mar, en gráfico | PlazaMoyua.com

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[…] Hansen’s backfire […]

Comment on Hansen’s backfire by -1=e^iπ

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That doesn’t make sense. You aren’t even taking the amount of warming into account. You are just taking 2 numbers (100 years for a century and 560 year decay time), dividing them and then assigning the result to something unrelated.

Comment on Eco – (post) modernism by Vaughan Pratt

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@DLH: For questions about the Creator, see Genesis, John, Revelation etc. But remember, The Hound of Heaven pursues with steady pace.

Look on the bright side, David. Recent estimates have found 2.18 billion Christians in the world. Given that there are only seven billion people altogether, you would therefore have at least a 2.18/7 = 31% chance of being smarter than them on average. There is therefore at least a fair chance that they would be your ideal audience, and possibly a very good one.

And such a huge audience! Since you’ve been persuaded that science can be reliably based on Judeo-Christian literature from 2+ millennia ago, so can they.

Go to it.

Comment on Hansen’s backfire by Tom Taylor

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I look forward to Judith’s knee jerk response in a day or two. We’ve certainly had plenty so far!


Comment on Hansen’s backfire by beththeserf

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Lotsa’ new industries fer innovative humans, jw,
imagine!

Comment on Risk assessment: What is the plausible ‘worst scenario’ for climate change? by Vaughan Pratt

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@AK: That is, if you follow a northwards path exactly normal to your perceived “downwards”, you’ll actually be getting a little closer to the center of the earth.

Yes, that’s the case we agree on. Please focus on the case of an EW or latitude-preserving path.

Comment on Hansen’s backfire by fizzymagic

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I find people who go by press conferences and bad books and reporters more than deeply disturbing.

But it’s OK with you for the author of a paper to misrepresent the paper’s contents in press release. Hmm.

Comment on Eco – (post) modernism by Don Monfort

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Depends on what the choice is, doc. Somewhere after 20 weeks or so, I say the kid has rights just like the rest of us. Let’s have a vigorous public debate on it and lay out all the evidence. Ultrasounds before and pictures after. We can get plenty of specimens from Planned Parenthood for about a hundred bucks each.

Comment on Hansen’s backfire by climatereason

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Tom

Some of us have been reading Hansen’s papers for years. This paper has been available for some time and has also been read.

What is your opinion of it?

tonyb

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