From Yale News: Climate models have underestimated Earth’s sensitivity to CO2 changes, study finds
A Yale University study says global climate models have significantly underestimated how much the Earth’s surface temperature will rise if greenhouse gas emissions continue to increase as expected.
Yale scientists looked at a number of global climate projections and found that they misjudged the ratio of ice crystals and super-cooled water droplets in “mixed-phase” clouds — resulting in a significant under-reporting of climate sensitivity. The findings appear April 7 in the journal Science.
Equilibrium climate sensitivity is a measure used to estimate how Earth’s surface temperature ultimately responds to changes in atmospheric carbon dioxide (CO2). Specifically, it reflects how much the Earth’s average surface temperature would rise if CO2 doubled its preindustrial level. In 2013, the Intergovernmental Panel on Climate Change (IPCC) estimated climate sensitivity to be within a range of 2 to 4.7 degrees Celsius.
The Yale team’s estimate is much higher: between 5 and 5.3 degrees Celsius. Such an increase could have dramatic implications for climate change worldwide, note the scientists.
“It goes to everything from sea level rise to more frequent and extreme droughts and floods,” said Ivy Tan, a Yale graduate student and lead author of the study.
Trude Storelvmo, a Yale assistant professor of geology and geophysics, led the research and is a co-author of the study. The other co-author is Mark Zelinka of Lawrence Livermore National Laboratory’s Program for Climate Model Diagnosis and Intercomparison.
A key part of the research has to do with the makeup of mixed-phase clouds, which consist of water vapor, liquid droplets, and ice particles, in the upper atmosphere. A larger amount of ice in those clouds leads to a lower climate sensitivity — something known as a negative climate feedback mechanism. The more ice you have in the upper atmosphere, the less warming there will be on the Earth’s surface.
“We saw that all of the models started with far too much ice,” said Storelvmo, an assistant professor of geology and geophysics. “When we ran our own simulations, which were designed to better match what we found in satellite observations, we came up with more warming.”
Storelvmo’s lab at Yale has spent several years studying climate feedback mechanisms associated with clouds. Little has been known about such mechanisms until fairly recently, she explained, which is why earlier models were not more precise.
“The overestimate of ice in mixed-phase clouds relative to the observations is something that many climate modelers are starting to realize,” Tan said.
The researchers also stressed that correcting the ice-water ratio in global models is critical, leading up to the IPCC’s next assessment report, expected in 2020.
Support for the research came from the NASA Earth and Space Science Fellowship Program, the National Science Foundation, and the U.S. Department of Energy.
(Note: title and date were corrected about 15 minutes after publication – this study was published in 2016, not 2017, and it was sent to WUWT as a tip. The error in not noticing the tip was for a study over a year old is mine- Anthony)
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In other words, once they add this to the models. The models that already run too hot will start running way too hot.
Plus many. An irrefutible logical conclusion.
Well they do need to do something to prove themselves right
This is exactly what I was thinking…the models will be even more wrong than ever!
And hey…i thought the science was settled anyway.
Now they tell us it took until 2016 and some grad student coming along to get a proper handle on what the correct composition of clouds is?
And i thought the models did not include clouds, except as a correction factor, because clouds are far smaller than the individual pixels in the models?
So just what they hell are they talking about?
Just to recap…until the authors penned this study, no one knew what the correct makeup of clouds was…but now they know “everything”, and can say with greater certainty than ever that the world will be hotter than anyone ever guessed?
Even though it actually proves the models are a larger bunch of crap than they already were proven to be.
Riiiiiiiiiight…got it!
*two thumbs up and a wink and a nudge*
In the Carboniferous Era CO2 was some 20 times higher than now and the world did not boil over. There was an explosive growth of trees.MG
From: Watts Up With That? To: mickgreenhough@yahoo.co.uk Sent: Friday, 28 April 2017, 16:49 Subject: [New post] New study tries to prop up shrinking climate sensitivity #yiv6342347846 a:hover {color:red;}#yiv6342347846 a {text-decoration:none;color:#0088cc;}#yiv6342347846 a.yiv6342347846primaryactionlink:link, #yiv6342347846 a.yiv6342347846primaryactionlink:visited {background-color:#2585B2;color:#fff;}#yiv6342347846 a.yiv6342347846primaryactionlink:hover, #yiv6342347846 a.yiv6342347846primaryactionlink:active {background-color:#11729E;color:#fff;}#yiv6342347846 WordPress.com | Anthony Watts posted: “From Yale News: Climate models have underestimated Earth’s sensitivity to CO2 changes, study findsA Yale University study says global climate models have significantly underestimated how much the Earth’s surface temperature will rise if greenhouse gas” | |
But bear in mind that: During that period of time, even though the world didn’t boil over, sea levels were significantly highet than today. In fact, sea levels were much higher than today through most of earth history as this Phanerozoic sea level chart indicates
Topping todays level by as much as 200m. This would eliminate most of the major population centers
Here is an interesting interactive map for sea level alterations
http://www.floodmap.net/
Set your desired sea level rise, pan about, and zoom in to any area on the map. The world might survive carboniferous era temps and life would go on but society would be decimated.
People can’t move inland?
You don’t think people would just move? As the sea level rises millimeters per year, they’ll hold their ground, toward the end just stand on their tippy-toes, and finally succumb to drowning? No chance that they’ll just move? Maybe their children will move out. Seems like there are so many options to drowning… slowly. Maybe you forgot your /sarc off tag.
I set the flood map for 100 years from now (300mm) and noticed no change.
Bryan A, if 200 meters higher sea level is normal, ie, not anthropogenic, how can you stop normal? For sure 200 meters higher sea level indicates most of the H2O budget of our planet is in the liquid phase, which is something not likely to happen again. I am much more concerned about snowball earth than 200 meters higher sea level. Actually I am not concerned aobut either.
The high sea levels in the past were largely not due to melted glaciers since there isn’t nearly enough water in all the glaciers in the world to raise sea levels 100 meters, much less 200 meters. The very high sea levels at certain intervals in the past were probably instead mostly caused by faster continental drift (=larger volumes of mid-ocean ridges).
By the way the Carboniferous was a quite cold interval with low sea-level, low CO2 and large continental glaciation. Just like now in fact.
Your logic only is valid if CO2 is a climate driver, instead of it being controlled itself by other factors. But the latter is the case, CO2 is not a significant climate driver at any level except at very low concentrations. The 200 meters variation over geological epochs has nothing to do with CO2 but everything with the distribution of landmass over the globe. In particular, levels are at their low end when there is a large landmass at either pole or both which can accumulate very large quantities of water in its frozen form.
“I set the flood map for 100 years from now (300mm) and noticed no change.”
You didn’t look closely enough. Death Valley and Imperial Valley are apparently going to turn into inland seas. Not to mention the Caspian….
so what ? using CO2 has nothing to do with it 🙂
Bryan, http://www.flodmap.net is so good that even at 0 meters, lots of features that are perfectly above sea today appear already flooded. Also the default value that appears is 397m. This value is simply impossible with the present amount of solid ice, even it all of it melted. This says a lot about the credibility of this “amusement” experience with a rather poor GSD STRM (90m/pixel). In the Eemian, the last interglacial period, its admitted that the sea was about 5 to 7 meters higher than today. I do not see any “exotic” factor that can lead to overall levels higher than those. As somebody is pointing out, we cannot compare the world in the carboniferous period with the present world. Remember that in that period the overall sea level was high because some interior seas were higher than today, sometimes a lot higher, not because the earth was hot and Ice was melting (Ice did not existed in the poles during the carboniferous) but because most seas were terminal interior seas that were later consumed by the final reunion of PANGEA!! Even if all the solid water melted, it was impossible, with a percentage lower than 2.15% of the earth water in the Icecaps and glaciers, to increase the sea level by 200 meters – pure nonsense.
If the seas were 200 M higher, men would move to higher ground. You, see, they have legs.
JN April 28, 2017 at 12:53 pm
There was an ice age in the Carboniferous and Permian, so, yes, there was ice at the South Pole then and probably sea ice at the North:
http://www.scotese.com/images/342.jpg
More extensive in the Late Carboniferous Epoch, known as the Pennsylvanian in North America:
http://paleoportal.org/media/boilerplate/0/21232_period_pal_map_12_image.jpg
JN,
The Eemian:
http://www.brightstarstemeculavalley.org/science/EemianEarth.jpg
Florida and most of Iraq submerged, Scandinavia an island (more from crustal depression than sea level rise) and the GIS reduced.
Chimp, ignore those gross reconstructions of the seal level in the Eemian as if the flood was only due to sea level. Those maps are simple exercises of plotting a sea level over the the present SRTM without account for other factors that impact in the coastline position such as marginal diastrophism and isostatic movements. in the Scandinavian peninsula, for instance, that uplifted a lot since the last glacial maximum, coastline historical positions do not reflect, per se, the average sea level. With an average level of 5 to 7 meters above the present level, it would be impossible, without other factors, to have all those areas flooded. It’s not only sea-level that matters.
Note – I work mainly in sea level reconstructions during the Holocene.
https://www.researchgate.net/publication/259248357_Environmental_reconstructions_of_Eemian_Stage_interglacial_marine_records_in_the_Lower_Vistula_area_southern_Baltic_Sea/figures?lo=1
JN,
Thanks for the more detailed map, and for your work. But it doesn’t look basically any different from my link, which naturally, being the whole world, isn’t as detailed.
A. Bryan: “Here is an interesting interactive map for sea level alterations
http://www.floodmap.net/“
Great fun map. I’m OK up to 70m and if I move to the airport, 110m. I’ll stay where I am for now.
People don’t NEED to move inland. The rise is a few centimeters per decade, same as it has been for centuries. Many places (like New Orleans) are already below sea level and have been for a long time.
Humans adapt. It’s what we do. Adapting to a change that will take Centuries isn’t even a good joke. We won’t even notice the difference. ~¿~
Oh my god!
https://www.thestar.com/yourtoronto/the_fixer/2017/04/26/high-lake-ontario-water-levels-cause-lakefront-parking-lot-flood-the-fixer.html
“I don’t know if there’s a blocked drain, but I couldn’t see any drains on Google Maps, otherwise I’d go back there and try to unclog it myself.”
No you wouldn’t.
There is a big drain. It’s called St. Lawrence.
Sea level in the Cretaceous was 250 metres higher because the newly expanding Atlantic ocean was still young.
New oceans start out as rift valleys, even rift valleys that are not flooded by ocean yet. The continued spread starts to bring in-flow from the ocean but they can still be just 100 metres deep. As time goes on, they get deeper and deeper, they actually sink into the mantle.
So the new ocean starts with no water, gets to 100 metres in 5 million years and continues sinking into the mantle until about 100 million years after the initial separation, that former rift valley is not 5,000 metres deep, the average ocean depth of a mature ocean.
So go back to the Cretaceous, the Atlantic ocean is only 100 million years old at it very earliest rift valley regions, but the rest of the ocean is only 2,500 metres and the mid-atlantic ridge is only 1,000 metre deep and the northern half of it hasn’t even split apart as a rift valley yet.
So what you have is the average depth of all of the oceans is literally 250 metres higher than it is today. All that water has to go somewhere at it goes onto the land. 94 million years 30% of the continental shelves were flooded by the ocean. The Gulf Stream literally flowed right up through the centre of North America from Texas all the way to the Arctic ocean. The Rocky Mountains had only started forming at this point and the Colorado Plateau has not risen yet. All of the central region was only 100 metres above what is sea level today. With 250 metres of more ocean water, it was completely flooded. Europe and the Middle East as well.
THAT is why sea level was 250 metres higher, in the Cretaceous.
Bill,
There was also some thermal expansion from such very warm, indeed hot, seas.
But sea level receded in the later Cretaceous.
It bugs me that the Cretaceous doesn’t have a Middle Epoch. The Early (46 million years) and Late (34 M) Cretaceous Epochs both lasted longer than the entire Silurian Period (25 M). The Ordovician lasted 41 million years. The shorter Triassic and Jurassic Periods both have Middle Epochs.
The mid-Cretaceous was distinctive and deserves its own epoch, IMO. It was not just warm, but hot, hot, hot! The seas went out in the later Late Cretaceous.
Ichthyosaurs went extinct in the Turonian Age. That would be a good place to end the Middle Cretaceous. Early Epoch Ages: Berriasian, Valanginian, Hauterivian and Barremian. Middle Epoch Ages: Aptian, Albian, Cenomanian and Turonian. Late Epoch Ages: Coniacian, Santonian, Campanian and the ever-popular Maastrichtian, portrayed below with its two most famous Montanans (when the Rockies were under construction).
http://pre05.deviantart.net/7066/th/pre/f/2015/274/1/b/t_rex_vs_triceratops_by_swordlord3d-d9bd8h3.jpg
You are absolutely right chimp.
Your TRex illustration taking down a Ceratops is from 67 million years ago when the ocean in central North America was gone already.
The average depth of the ocean had fallen by 100 metres at this time and uplift in central North America had made it a great place for a great illustration. 30 million earlier the scene would have looked like this.
Bill,
Right on!
You want climate change, I’ll show you climate change!
With very little difference in CO2, you go from the oceans of Kansas, dominated by giant shark and pliosaur-eating snake kin, the mosasaurs, to the tyrannosaurs of Kansas.
I’m not saying which factor was the driver and which was the result. I’m only saying:
Although the world has been warmer over a significant portion of the past and life survived, we don’t necessarily want it to be that high now (not that we can do much to affect it one way or the other) due to the repeated effect on sea level.
We can’t just pick up a city of 10 million and move it 500 miles inland. Last I checked high rise buildings didn’t have legs or wheels. How long would it take to rebuild every city under potential flooding loss 500 miles inland? Then the only place open to relocate the population centers would be where we grow our crops today. And far to many people are shy of “Walls” right now. Not many tourists would want to visit Miami Beach (without a beach) and have a 75′ or 100′ tall seawall. They would have to rename the town’s Miami Wall and Daytona Wall and South Wall. That type of adaptation wouldn’t work well with Phanerozoic era temperatures today so please try not to use that as an argument it makes little sense.
Realistically you wouldn’t set the depth of flooding greater than 70 meters as that’s about the max for all current ice
Sheri,
Sure people could move inland. Large Populations require significant resources to do so though.
50 families could quite easily relocate inland and pose no problem. But where would 8,000,000 Los Angeles residents relocate to? They would need an additional 2,000,000 vacant houses and support infrastructure businesses etc. just for the LA basin populace. Then the Sacramento Valley, where many of the nation’s crops grow, would also be underwater.
Bryan A April 28, 2017 at 11:05 pm
No way will all the ice melt. Not even a small fraction, under the “worst” case scenario.
The East Antarctic Ice Sheet, repository of most of the fresh water on earth, formed under conditions much warmer than now.
It would take thousands of years or more to melt the Greenland Ice Sheet even at higher temperatures than now. The Eemian lasted 16,000 years and was hotter than even the Holocene Optimum. Yet only the Southern Dome melted maybe some 25% more than now.
Maximum, worst case scenario would be less than ten meters MSL rise over thousands of years.
Easily adapted to.
Think you mean the Cambrian Period (~7000 ppm high), not the Carboniferous (~300 ppm low), which suffered an ice age.
Speaking of ice, I note that, thanks to the cooler than usual Arctic Ocean, sea ice is melting more slowly than normal. According to NSIDC, from April 26 to 27, Arctic sea ice extent dropped a mere 0.008 million sq km. Average for those dates is 0.042. This underperformance has characterized the whole melt season so far.
Sorry, Griff, but extent is now above last year’s at this time. Your prediction that 2017 was “sure” to mark a new record low isn’t looking too good at the moment. But maybe you’ll luck out with two Arctic cyclones in August again this year.
The cooler ocean SST might be because of a lower than average maximum sea ice extent last winter, allowing more heat to escape to the air, thence to space.
Griff was warned that this scenario was likely to play out.
Chimp, although you are right about the IceCAP in the late carboniferous, you have the notion that those Scotese maps, published in 1975 and 1976, when most of the geologists do not even admitted that plate tectonics was real, are very outdated. I studied paleogeography by those ones when I was very young ;-). Check for more recent ones that show a better paleogeographic reconstruction based on thousands of regional studies worlwide in recent years and by data of the LAGEOS mission.
JN,
There is every reason to believe that there were extensive ice sheets and caps in the Carboniferous and Early Permian.
I studied geology at the world’s top geology university from 1969-72, so can assure you that plate tectonics was fully accepted by that time. The discovery of seafloor spreading in the 1950s made for rapid adoption of the previously shunned theory of “continental drift”.
Besides which, the Scotese maps are from 2003.
http://scotese.com/
Chimp, the site you took them from http://www.scotese.com was last updated in 2003 but the maps are are painted graphical edited versions based on the earlier works from Scotese. If you study a little of tectonical paleoreconstruction you will easily see that they are still great maps but they do not fit in the most regional present stratigraphical knowledge.
In 1972, most European geologists were yet verticalists with lots of problems to admit that plate tectonics was right and even less admitting that there was a thing so-called Neo tectonics 😉
History proved that they were wrong, of course!
JN,
Scotese is an American, who got his PhD from U. of Chicago in 1985. His Paleomap Project (U. of Texas, Austin) thus is more recent than the ’70s. I don’t know to what extent he might have relied upon reconstructions from before the 1990s.
https://en.wikipedia.org/wiki/Christopher_Scotese
Yeah, I’m still waiting for Mosher’s ‘alligators in the arctic.’
Maybe Arctic alligators is one of those “dangers” from global warming of which the past POTUS spoke. Or maybe hippos in London again, as during the previous interglacial.
See my above explanation. They got there because the Gulf Stream flowed all the way up into the Arctic ocean 94 million years ago. The crocodiles got there right around this time for a short period of time following the Gulf Stream flow but they probably all died in the winter when it got cold. Hence the fossils.
Hey! Has anybody ever seen Mosher & Griff in the same place at the same time?
“If the seas were 200 M higher, men would move to higher ground. You, see, they have legs.”
Can you provide a link to a peer-reviewed study, published in a respectable journal, to back up this claim about legs?
That paper is already more than 1 year old…
[still valid to discuss – afaik, it was not covered here -mod]
Climate science has best-before dates??
Possible, if there is a more recent paper that refutes the older paper.
Generally speaking the “use or dispose of by” dates for “climate science” are the dates of publication.
CO2 levels have risen by a factor of 4/3 since 1960. Assuming a logarithmic relationship of temperatures to CO2, this estimate of the sensitivity implies that a warming of 2 degrees centigrade should have occurred since 1960.
Could somebody much more knowledgeable than I answer Michael Palmer’s comment? Given that CO2 levels are around 400ppm is there a point in the historical past when levels were half that? That would be a ‘doubling’, not so? And what have been the effects of that doubling?
My comment doesn’t require an ‘answer’ — it just simple math:
sensitivity estimate (5 degrees per doubling) * log(4/3) / log(2) = 2 degrees (approximately)
But there have been times with CO2 levels approximately half as high as today: the deep-freeze periods of the ice ages. But note the order of cause and effect — the colder oceans dissolve and sequester more of the atmospheric CO2. It is CO2 that responds to temperature, not the other way around.
Not quite. The Sensitivity referred to is ECS. This is reached over hundreds of years, so does not speak to the temperature rise from 1960 to now. One could use this logic IF thenYale paper also estimated TCR (transient climate response) which is to an annual 1% increase in CO2 until doubling (70 years). Because then the decades long time frame can be imputed.
Doesn’t the bulk of temperature increase occur in the first few decades, with a very long tail for the rest? since heat moves into the oceans very slowly.
“The Sensitivity referred to is ECS. This is reached over hundreds of years, so does not speak to the temperature rise from 1960 to now.”
No, and since most of the CO2 is not going to hang around in the atmosphere until equilibrum is reached (which takes at least 1,000 years) ECS doesn’t exist in the real world.
During the depths of glacial phases, such as the LGM some 20,000 years ago, CO2 was less than half of now, ie perhaps 180-190 ppm. But conditions were very different, so it’s not a valid comparison. Albedo is affected by the vast ice sheets then covering much of the NH, while today all we have is Greenland and some mountain glaciers and ice caps. Wind patterns, oceanic circulation and a number of other climatic parameters besides temperature were different as well.
The CO2 was lower because the oceans were colder. The world wasn’t colder because CO2 was lower.
This paper talks about Equilibrium Climate Sensitivity. In models it takes 150+ years to get there in response to the forcing.
Which studies have you read on the long-term response of climate change? Anything by Knutti or Armour?
OK, my bad. I didn’t realize it takes this long to reach equilibrium.
Michael Palmer;
Everyone gets tripped up by this once in a while! There’s TCR and ECS and ECS_eff and ESS… just the other week a new paper came out trying to work out a way to understand how TCR and ECS relate to each other a little better:
http://www.nature.com/nclimate/journal/v7/n5/full/nclimate3278.html
You might not have realised at the time, but your comment brings up a big question: if this is the real equilibrium sensitivity, then it means that a lot of warming is in the pipeline. The physics behind how that’s possible is really interesting IMO. Personally I don’t think the 5 C result is very likely, but that’s no criticism of Ivy Tan’s work, it’s just because other factors that they weren’t testing in this paper will probably cancel it out a bit.
When estimating climate sensitivity, Climate scientists seem to omit the shift from a cooling cycle to a warming cycle. circa 1850, the earth shifted from a cooling cycle to a warming cycle, That shift was a much greater swing than the rate of warming from the 80’s to late 90’s. This shift occured when CO2 went from 280ppm to 281ppm.
So tell me again what a reasonable estimate of CS is for a doubling of CO2
There is NO way anyone can calculate a 5.5C ECS.
One would have to failed Grade 9 math to get to this value and, hence, you have your answer what went wrong with this study.
What I see here is an enormous range of CO2 sensitivity,displayed on the chart,that tells me that the subject is not that well understood.
Personally I see very low sensitivity, because there will never be much IF any Positive feedback show up.
The water vapour feedback has been measured, e.g. doi: 10.1029/2009RG000301
Hell, even Watts’ AGU poster last year showed that the CERES satellite data support water vapour feedback just like the models calculate.
….except it isn’t.
Two can make unreferenced assertions…
“The water vapour feedback has been measured, e.g. doi: 10.1029/2009RG000301”
The paper is freely available here:
http://opensky.ucar.edu/islandora/object/articles%3A10468/datastream/PDF/view
So anyone can read it and see that you are lying. What it does show is that by using three different GCM together it is more or less possible to match observational data, though none of them alone is even close….
Ironically the paper also argues that cloud microphysics (which is at the heart of the Yale study) is climatically unimportant.
You can get the water vapour data from microwave sounders here:
http://www.remss.com/measurements/atmospheric-water-vapor/tpw-1-deg-product
Warming, more vapour. Just like physics said.
>>
MieScatter
April 28, 2017 at 9:45 am
The water vapour feedback has been measured, e.g. doi: 10.1029/2009RG000301
Hell, even Watts’ AGU poster last year showed that the CERES satellite data support water vapour feedback just like the models calculate.
<<
Except that pan evaporation has been decreasing for the last 50 years in direct conflict with GW theory and water vapor feedback.
Jim
Jim Masterson:
Citation needed for global 50-year pan evaporation data.
And evaporation is related to the lapse rate feedback, not the water vapour feedback. Models say that they correlate, but if you don’t believe their physics then in principle you can have massive water vapour feedback and no measurable change in evaporation.
Water vapor is only between 1.0% to 3.0% above normal right now.
It is supposed to be 7.0% higher given temps (measured by the NCDC) are 1.0C higher.
Everyone who quotes water vapor feedback is just taking advantage of the ENSO timing because the ENSO appears to control at least 90% of global water vapor levels. When the next La Nina hits, water vapor will below normal.
I can prove this if you want.
“…cloud microphysics … is climatically unimportant.”
It is common practice in modelling to claim that anything you can’t model is unimportant. Wrong of course, but common practice.
>>
Citation needed for global 50-year pan evaporation data.
<<
I remember discussing decreasing pan evaporation 15 years ago. But try Wikipedia for starters:
https://en.wikipedia.org/wiki/Pan_evaporation
Jim
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
I was under the impression that the climate models did not include the effect of clouds of any type, just some fudge factors.
That was my understanding as well. Since cloud behavior can’t be well modeled (or even badly modeled), cloud effects are paramaterized.
The models all have a way of calculating cloud type. The model Tan et al. used, CAM5, for example, outputs water content, ice content, droplet size, ice crystal size etc.
From the parameterization. Not computation from first principles.
Hmmm, how does the model “create” the clouds? What inputs say “make clouds here, now, of this type”?
It seems they are simply trying to make the parameterizations more accurate. As far as I know, we still cannot handle sufficient resolution in models to actually input real cloud data.
They seem to be saying that as temperatures increase, these models show that the make up of certain clouds will change.
Since we have a wide variety of climates over the planet, why not go out and measure clouds at different temperatures rather than relying on a model?
D. J. Hawkins:
“Hmmm, how does the model “create” the clouds? What inputs say “make clouds here, now, of this type”?”
Try file cam5_desc.pdf here:
http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/description/
p93 onwards describes the cloud physics.
Mark W:
“Since we have a wide variety of climates over the planet, why not go out and measure clouds at different temperatures rather than relying on a model?”
That’s a great experiment idea. Would you accept the results of such an experiment, regardless of what they are?
Why do you assume that I wouldn’t accept the results of an attempt to actually measure the real world?
Assuming their methodology and statistical techniques pass muster of course.
Mark W:
“Why do you assume that I wouldn’t accept the results of an attempt to actually measure the real world?”
Because that’s what the Tan et al. paper is all about, with the help of some other recent work like Cesana et al (2015, doi: 10.1002/2014JD022932 ).
They used the lidar on CALIPSO to look at clouds worldwide. The results say that a cloud cooling effect will be smaller than originally calculated by the model. Isn’t that a reasonable approach where you should take the results seriously and not dismiss them out of hand, or just assume that they didn’t take any measurements?
What? They’re bucking the concensus of ECS estimates? Very suspicious…
There are a bunch of these emergent constraints based on observations, and they constantly favour higher warming. It’s still an open question whether that’s really the case or whether something else compensates for them, which puts us back at the IPCC range for our best estimate of climate response and sensitivity.
I think the graphic should have included Lewis and Curry (2014) and Lewis (2015), which indicate equilibrium climate sensitivity being higher than the studies shown in the graphic do, but still below the IPCC model range and projection.
DK, the Lewis and Curry 2014 central estimate is ~1.65. The Lewis 2015 (using Bjorn Smith’s new aerosol estimate) is ~1.5. Thos are lower than most in the figure. They are also more tightly bounded than most in the figure.
If you do the Lewis & Curry calculation on the CMIP5 models, you get about the same result for transient climate response (model mean or median within 0.1 C).
http://www.nature.com/nclimate/journal/v6/n10/full/nclimate3066.html
So there’s no strong evidence of disagreement between models and observations for any of the terms in the Lewis & Curry calculation. When you know the answer in a model though, their calculation gives a lower result.
Overall, Lewis & Curry would favour something like 2.5-3 C for equilibrium after you include the Stevens aerosol stuff.
http://www.nature.com/nclimate/journal/v7/n5/full/nclimate3278.html
Ristvan, you are correct. I looked at the graphic again, and I see a central number being about 2 degrees C per 2xCO2, more than my first impression. But Lewis and Curry (2014) is bound asymmetrically, more upwards than downwards. And now that I see that these two studies indicate lower ECS than most of the ones shown, I still think they should have been included – this time because they would have helped the original poster’s point.
So can anyone explain to me how they know how much ice there will be in clouds in 2050, and how many clouds there will be? If we get more cloud cover in 2050 and slightly less ice in the ice:water ratio then the extra cloud cover could more than offset the lower ice:water ratio. Where did I go wrong? Did I go wrong by assuming all mechanisms will NOT lead to more and more warming?
Tan et al. allowed the physical parameters used to calculate cloudiness to change. They then selected those which matched the observations of satellite-mounted lidar.
Once you select the parameters that match observations, the models warm more. They could have selected parameters that disagreed with observations and maybe would have got less warming, but that doesn’t make sense to me.
If they got parameters that made it cool using the observations, the paper would have gone in the trash and never seen publication. The accuracy is irrelevant. We don’t know how many studies met this fate, so it’s kind of tough to know where the research is going.
OK, let’s select the increasing shoe/waist size parameter and see how that fits climate warming observations – Wow! A positive correlation. I think we are on to something.
MieScatter, “Tan et al. allowed the physical parameters used to calculate cloudiness to change.” Do you honestly think that something as complex as cloud can be “parameterized” and give anything but a garbage answer?
Thomas: PV = nRT is a parameterisation and it works great.
If one parameterization of a very simple well understood relationship is good. Then all parameterizations must be good.
PV = nRT is a natural law. A parameterization is something like, “when temperature goes up by n °C, change clouds to …”
In other words, when the system is too complex to calculate the actual physics (like PV = nRT) the models just apply a simple rule of thumb. That’s parameterization. Right?
Seems like MeiScatter didn’t like my comments. Reminds me of other commenters who keep insisting they’re right, then scatter when you show they’re wrong.
Mark W, Thomas:
Thomas’ claim was “Do you honestly think that something as complex as cloud can be “parameterized” and give anything but a garbage answer?”
Gases are incredibly complicated, with trillions upon trillions of molecules bouncing around in every possible direction and with a wide distribution of speeds. The number of collisions is insane and it’s impossible for us to even calculate the trajectories of one millionth of the number of molecules in the air in a single bedroom.
But the ideal gas law, which effectively parameterises the statistical mechanics of gases, works great in these conditions. Thomas’ claim that complexity means parameterisations are garbage is wrong.
Clouds are complex, but they still obey physics. We’re getting better at them all the time.
CERES is actually calculating ZERO cloud feedback. I’m surprised anyone in climate science would just ignore these numbers.
>>
Clouds are complex, but they still obey physics. We’re getting better at them all the time.
<<
From a recent text on GCMs:
In other words, cumulus convection is made up–parameterized.
Jim
I should give credit where credit is due. The text is “Atmospheric Circulation Dynamics and General Circulation Models” by Masaki Satoh, pp 515-516.
Jim
Here is the actual “cloud forcing” as measured by the CERES and ERBE satellites.
Given the NCDC’s temperature estimates we should have seen at +0.5 W/m2 increase in the net cloud radiative effect and according to TAN 2016, it should have been at least 1.0 W/m2 increase.
CERES since 2000 says NO CHANGE at all. It is possibly even down a bit.
And then from 2000 back to 1990 using the ERBE satellite – the darkest black line here. Again nothing really happening except for the 1997-98 El Nino which went away afterward.
So where is this big cloud feedback showing up ?
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
>>
Jim, the ideal gas law is a parameterisation. Do you think that the physics of gases are “made up”?
<<
No, but it’s nice that you finally gave it its proper name. It’s one thing my professors always stressed: the ideal gas law only applies to ideal gases. With real gases, it’s only an approximation. However, you need more than pV = nRT to calculate cumulus convection.
Jim
“misjudged the ratio of ice crystals and super-cooled water droplets in “mixed-phase” clouds — resulting in a significant under-reporting of climate sensitivity.”
So you make an error in the specification of a variable that implies that the model’s error will increase? That, by definition, says the model was incorrectly specified in the first place. It’s a lot like saying if I raise the price of SPAM then SPAM’s sales will increase.
Once again the intended consequences of the AGW proponents boomerangs.
Clearly, the science is not settled.
Steve Fraser has it.
Sure it is. It’s just the details they’re working out. 🙂
94.7% of studies of ECS agree that this study is wrong.
Proper form for modeling ECS.
http://www.dartbase.com/curve.gif
Perfect!
Where’s the blind monkey?
So is this “settled science” or not?
“We saw that all of the models started with far too much ice,” said Storelvmo, an assistant professor of geology and geophysics. “When we ran our own simulations, which were designed to better match what we found in satellite observations, we came up with more warming.”
This suggests that it is NOT settled science. Settled science does not mean that you can use new information that changes the previous incorrect assumptions when that information requires adjustments one way………..that offset other previous incorrect assumptions that were in the opposite direction.
When advocates refer to this as “settled science”, I find they mean it’s settled that CO2 is rising, rising temperatures are bad for humans and we must act. There are some that demand you believe it’s CAGW and any statement to the contrary is wrong, but most just mean the temperature trend line keeps going up and that’s a bad thing. Average citizens are very visual—if you show them a graph that shows the temperature going up and tell them that’s the trend line, they don’t ask how you got the line. They just believe that it’s happening and it’s bad to have a rising trend line.
“When advocates refer to this as “settled science”, I find they mean it’s settled that CO2 is rising, rising temperatures are bad for humans and we must act.”
That would be perfectly acceptable, if people like me, who agree with the direction of the trendline but not the slope or the danger(and see many benefits) were not referred to as “Deniers”. This implies that we must disagree with settled science. If it was just the expected uncertainty within the settled science and unresolved specifics of the settled science, then we would not be Deniers.
It goes something like this:
Settled science is that the current trajectory of increasing CO2 will lead to 2+ deg. C of warming and all sorts of negative consequences.
If one believes that this will lead to less than 1.5 Deg. C of warming and along with a few negative consequences(like more flooding) are a host of benefits, we are Deniers.
If one believes that this will lead to 4 or even 6 degrees of warming and catastrophic consequences, this is not reason for being called a Denier. Guessing too high, above the range of most estimates is acceptable.
OK, those that are more conservative with their estimates would call this group “alarmists” but the mainstream media and commonly held perception is that if you’re estimates are low, you are a denier(of the settled science). If your estimates are high, you are portrayed as using settled science and projecting a realistic, worst case scenario……..something that should be considered. Deniers on the other hand, should be ignored, discredited, punished and exposed because they don’t follow the “settled science”.
Life on this greening planet has been telling us the past 40 years that it likes slightly warmer temperatures and increasing CO2 and is asking for more of it.
Funny how life and the biosphere of this planet , are in fact………..Deniers!
Good grief.
Draw conclusion… collect evidence… adjust evidence to fit conclusion… repeat.
They’ll never stop, will they?
Climate “Science” in a nutshell.
Minor correction: Draw conclusion… collect evidence… adjust evidence to fit conclusion… collect money… repeat.
The estimates of ECS have not gotten any precise since the 1979 Charney Report. They seem to be trying to patch a broken model.
I don’t usually patch a hole with repeated blows from a sledge hammer. That makes the hole bigger. They’re making the error bigger. Are they actually trying to blow the whole AGW thing by reductio ad absurdum?
Paleoclimate and Earth’s energy budget give about the same range too.
No they do not.
Stop lying.
Earth’s Energy Imbalance is only 0.675 W/m2/year – I just calculated it.
Now GHG forcing is about 2.3 W/m2 and feedback should add another 2.1 W/m2 to that or a total of 4.4 W/m2/yr should be showing up.
Yet only 0.68 W/m2/year is measured which means that ECS can only be in the 1.2C range. Only people who failed Grade9 math can calculate a higher number based on the current energy balance (which actually fell over the last 18 months, as in more energy left the Earth than entered it).
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
Paleoclimate:
http://www.nature.com/nature/journal/v491/n7426/full/nature11574.html
This study cherrypicked about a dozen specific times and ignored the 25,000 other data points.
This is the actual Paleoclimate Sensitivity over the last 50 million years when one uses all 25,000 datapoints.
http://s29.postimg.org/631jjig9j/Equil_CO2_Sensitivity_Last_50_Mys.png
Sorry, I should have added that it appears to be entirely RANDOM given any value between -40.0C per doubling to +40.0C per doubling appears to work.
Mie,
The paleo link is unspeakable garbage. Sadly, entirely typical of the organized criminal conspiracy of so-called consensus climate science, as opposed to real climatology. It’s false on its face. How could anyone with even a passing familiarity with climate history possibly credit its lies?
http://i90.photobucket.com/albums/k247/dhm1353/Climate%20Change/PhanerozoicCO2vTemp.png
As you can see from the above, all epochs, periods, eras and eons prior to the last 65 million years show the paper’s “estimates” of ECS to be preposterous. CO2 has fallen steadily, with two minor bumps up, since the Jurassic/Cretaceous boundary, which was an Ice House interval. Which shows the ECS nonsense to be complete and total rubbish, since the mid-Cretaceous was the hottest interval of the Phanerozoic Eon, and the Paleocene/Eocene Epoch boundary close. But consider just the interval of this “study”, ie pack of lies, the Cenozoic Era.
The Paleocene and Eocene were warm, so naturally CO2 was high, but it fell fairly steadily due to natural causes having nothing whatsoever to do with the GHE.
Antarctic glaciation began at the Eocene/Oligocene boundary because of the formation of deep ocean channels between that continent and Australia and South America. The ice sheets retreated somewhat during the Miocene because tectonics temporarily shoaled those channels. CO2 responded to the warming which occurred due to reduced albedo. CO2 is an effect, not a cause of warming and cooling.
Then, in the Pliocene, cooling started up again as the channels deepened once more and Antarctica was isolated by the Southern Ocean. This process was enhanced at the end of that epoch, when the Isthmus of Panama formed, altering NH oceanic circulation. More moist air was carried to the North Atlantic region, leading to ice sheet formation on Greenland, and eventually North America and Eurasia as well. The Pleistocene glaciation was on.
Plate tectonics (and the 150 million year cosmic cycle) account for the Neogene glaciations. CO2, not at all. It’s along for the ride.
Whilst I think we should all welcome as much academic research into our ever changing climate, why must muppets like these, continually select a single element of an incredibly complex and dynamic system, and make dramatic claims like this?
Shooting their own credibility in the foot just doesn’t begin to approach it.
Laughably, there will be a generation of these people who, in 20 years or so, will have to rely on these papers, as part of their CV, to get jobs.
Good luck.
They are trying to refute recent studies that measure real world temperatures in an attempt to estimate the ECS, by creating a new model that says it’s worse than we thought.
In other words, ignore the real world.
HotScot: “Whilst I think we should all welcome as much academic research into our ever changing climate, why must muppets like these, continually select a single element of an incredibly complex and dynamic system, and make dramatic claims like this?”
I think Tan’s approach makes sense, and they’re careful not to make crazy claims. From their abstract: “we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations.”
Pretty weak phrasing for a “dramatic claim”, especially considering the painstaking effort that’s gone into gathering the data and working out the physics.
“in simulations”
Making claims of anything from simulations is dramatic.
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
Hmmmm…. The Yale report appears to be doubling down on an already bad climate model bet.
However, when your playing with other peoples money, the losses from your bad bets have no personal consequences, do they?
IOW, counted faeries on a pinhead.
When CO2 leaves the surface of the Earth, whether from a fire, exhaust, flue or The Dirt, it does so with as many energy levels full as it can carry. It cannot trap any more energy without releasing some first.
Hence you can think of it as like the phosphor in a fluorescent tube, changing UV from the mercury vapour inside the tube into visible light (white) light that leaves the tube.
CO2 intercepts relatively hot/high-energy/short-wavelength photons and releases longer wavelength, colder photons without increasing its own temperature or that of its surroundings. As such, it has a cooling effect.
Just wondering, wasn’t Absinthe all the rage around Arrhenius’ time, or was he making tea from poppy seed stolen from a bakery, or using mercury to search for the Philosopher’s Stone? Isaac Newton certainly did. (mercury)
It was especially popular around Valentines’s Day.
Because Absinthe makes the heart grow fonder.
My limited knowledge of GW (compared to the folks here) tells me that CO2’s only effect supposedly is to increase atmospheric H2O levels which is the greenhouse gas of consequence. Increased H2O leading to GW isn’t a debate point but how the magic gas CO2 does that is a mystery to me as I suppose it is to others.
Are not the CO2 absorption bands already filled by other gasses? How does doubling, tripling or even quadrupling CO2 have any large effect other than to increase carbon sequestration in increased biomass?
CO2’s absorption bands are not saturated, and certainly not at all levels of the atmosphere. Its heating effect has been measured over the last decade ( https://www.nature.com/nature/journal/v519/n7543/full/nature14240.html ).
There’s a free version of MODTRAN that can show you the effect on fluxes at each layer of the atmosphere.
http://climatemodels.uchicago.edu/modtran/
I wouldn’t believe what you read in WUWT articles about stuff like radiative transfer.
Perhaps MieScatter, you can explain how CO2 produced twice the heating the sun does. That is always incomprehensible to me, yet I have heard it over and over.
Dear MieScatterBrain,
Perhaps you should READ the links you post. Your Nature paper does not mention anything about a “heating effect”.
Like were going to REALLY learn something about radiative transfer from some clown posting a comment.
And by the way don’t believe that radiative transfer is the dominating heat transport mechanism in the troposphere. It isn’t. Convection is dominant, so measuring that increased CO2 has an effect of 0,02 +- 0,01 Wm-2 and year is pretty irrelevant.
SkepticGoneWild:
“our Nature paper does not mention anything about a “heating effect”.”
…
from the abstract:
“The time series both show statistically significant trends of 0.2 W m−2 per decade “. More heat going down to the surface (in W m-2, or Watts per square metre) = heating effect.
tty,
That paper verifies the calculations for surface trends. They’ve also been checked by satellites and, for shorter periods, aircraft. The measurements agree amazingly well with the models, so we can be confident in the 1.82+/-0.19 W m-2 extra heating that our CO2 has caused directly.
Sheri: which papers have you read on forcing efficacy so far?
MieScatter brings up the Feldman 2015 paper which measured an increase in downwelling radiation in the CO2 frequency band. However, for some reason did not mention Gero/Turner 2011 which showed a decrease in all downwelling radiation across the same time period at the same location. Hence, an overall cooling effect.
When I see people do this I know they are dishonest.
Richard M: total downwelling radiation at one location depends on everything in the atmosphere above, including its temperature, humidity profile etc. At a single location, there could easily be a change in cloudiness or similar over a decade that effects the total trend.
The spectral information from Feldman confirms that CO2 has been increasing its heating effect, just as predicted by models. Satellites confirm that globally, the change at the top of the atmosphere is just like physics said too.
Scientists can calculate these spectra with amazing detail. Those who attack physics have never, *ever* been able to calculate the observed spectra and their changes. They’ve just whined about it for decades.
MieScatter: “At a single location, there could easily be a change in cloudiness or similar over a decade that effects the total trend.”
And there could have been no change. In addition, this decrease was also under all sky conditions so that the decrease under clear sky would not be affected by clouds. You’re making excuses and showing your bias. Sounds a lot like denial.
But here’s the big issue. If we have the ability to measure the radiation from all that “trapped heat”, then why hasn’t it been done all over the world? Build a 100 stations and measure it. This would balance out any local changes. The fact this has not been done tells inquisitive people that climate science does not want to know the answer. Now why wouldn’t they not want to know the answer?
MieScatter, are you saying you have found the “Hot Spot” and all that down dwelling is causing more “heat trapping clouds” which block the direct sun light?
old construction worker: Nope, those are completely different things.
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
Modtran actually shows that CO2 is cooling off the Earth because once one gets to 10 kms high to 30 kms high, CO2 is, by far, the primary molecule emitting energy to space.
That is all that Modtran actually shows.
All of the graphs you have seen portraying “CO2 Absorption” is actually showing CO2 “emitting energy” to space in the stratosphere. Its a unusual situation where “CO2 absorption patterns” are actually “CO2 emitting energy away” from the Earth.
But most people have fallen for it.
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
Fluorescence is not the mecahnism with atmospheric CO2; absorption and emission of thermal radiation is. Also, fluorescence causes heating of the fluorescent material.
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
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CO2 molecules collide with other molecules and transfer heat in that way.
<<
They used to call it “quenching” or “thermalization.” I’ve not seen the term quenching used recently.
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This is physics 101 stuff.
<<
No it isn’t. They never covered radiation and thermodynamics in physics 101.
Jim
Desparate for job and funding preservation, these sorts of fake climate science papers will continue to find their way into Science and Nature.
Which part of the paper do you disagree with? Pages and line numbers would help. Why do you disagree?
So it has been a year. How was it received by “The Team” ?
Surely the “The Team” must be all on-board with these new much higher numbers. If not why not? (Because there is not evidence for it, perhaps)
The CALIPSO data show that supercooled liquid cloud droplets already exist in nature at cold temperatures. So it’s impossible for there to be the increase in their fraction as calculated in the original CAM5.
Do you think that the lidar phase discrimination method is wrong? Why? Have you published your calculations anywhere? Is your method validated with field data?
The CALIPSO data and the airborne cloud sample data taken directly underneath CALIPSO are publicly available if you want to check.
“Have you published”—weasal words.
Please, don’t get into Sicilian tones. The measured phases are right probably, but ECS being too small in models is rather far-fetched. You just found an error, and it is not the only one.
MieScatterBrain stated:
“More heat going down to the surface (in W m-2, or Watts per square metre) = heating effect.”
Seriously? W/m-2 is not “heat”. Ice gives of thermal radiation in W/m-2, but it does not heat your up. Were you drunk during physics lecture? You confuse “heat” and “energy”.
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
It would be nice if the climate sensitivity for all greenhouse gas were published, not just CO2. The “Popular” press tells us over and over again how many times more potent methane is as a greenhouse gas than CO2. This meme tells the average person absolutely nothing about how much methane will run up the temperature or how long it will take. I’m outraged that the skeptical side of this issue doesn’t call bullshit on this obnoxious propaganda.
Have you read any papers on forcing efficacy? Which ones?
Well-mixed greenhouse gases tend to be pretty similar to CO2. Responses to solar, aerosol, land-use change can be quite different.
Notice “Well-mixed”. That is the giveaway. Water vapour is the dominant GHG, but it isn’t well-mixed, so it’s not kosher.
MieScatter – 9:56 – Have you read any papers on forcing efficacy? Which ones?
Methane is umpty bump times more powerful than CO2 vs. it will run the temperature up so much by such and such date, isn’t an issue for me to read up on it, it’s a issue for the news media and the scientific community to stop engaging in blatant propaganda.
Steve Case –
So you haven’t read any papers but you’re certain that you know better than all of the researchers who’ve worked with the data and done the calculations, and you know they’re wrong by a factor of “umpty bump”. Right?
MieScatter April 28, 2017 at 1:03 pm
Steve Case –
So you haven’t read any papers but you’re certain that you know better than all of the researchers who’ve worked with the data and done the calculations, and you know they’re wrong by a factor of “umpty bump”. Right?
I know that they don’t want to say how little methane will actually warm the planet.
How much do you think methane will warm the warm the world if you double its concentration? And how long that will take? While you’re at it, show your work on how knowing that, “Pound for pound methane is 86 times more potent than CO2” helped you arrive at that figure.
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
Steve Case: the term is Global Warming Potential [GWP]. Which papers have you read on this so far?
Why would I want to read any? It’s a meaningless statistic that can’t be put to any use to tell anyone anything useful about any greenhouse gas. For example:
How much of a particular greenhouse gas is in the atmosphere?
How does knowing its GWP tell us that? It doesn’t.
How much an increase in a particular greenhouse gas will warm the planet?
How does GWP help us answer that? It doesn’t.
How fast a particular greenhouse is increasing or decreasing in the atmosphere?
How does GWP help us find out what that is? It doesn’t.
How much we can scare an uneducated populace into passing unnecessary regulations of a particular greenhouse gas?
How does GWP help us do that? Oh yes, that it does quite well. Eighty-six times more powerful than CO2 is very dramatic. Perfect propaganda, a genuine statistic as true as the average telephone number in the New York phone directory and just as useful, but very scary indeed.
Where do we find this scary number?
IPCC AR5 Chapter 8 Table 8.7
or
IPCC AR4 Chapter 2 Table 2.14
The astute reader will note that the Global Warming Potential values have changed from the AR4 to the AR5. That’s because it uses the concentration of CO2 as a standard and the concentration of CO2 changes over time which makes it as a standard as useful as a rubber yard stick.
But Mr. MieScatter I asked you how much methane will run up the temperature if you double how much is in the air and how long that will take? And to say how much knowing the methane’s GWP helped you in achieving that answer.
I’m guessing you will come up with or you already know the answer, but you won’t say what it is. (because it’s not very much) Which of course means you won’t tie the answer to methane’s GWP either.
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. . . the term is Global Warming Potential.
<<
There is no GWP for either water vapor or ozone–two very potent GHGs. And the GWP for CO2 is defined as 1–the lowest of any GHG.
Jim
Jim Masterson April 29, 2017 at 9:39 pm
>>
. . . the term is Global Warming Potential.
<<
There is no GWP for either water vapor or ozone–two very potent GHGs. And the GWP for CO2 is defined as 1–the lowest of any GHG.
Jim
The Global Warming Potential is a meaningless statistic dreamed up to scare people. The notion that methane is pound for pound 86 times more potent than CO2 at trapping heat serves no useful purpose other than its use as propaganda to bully the populace into demanding that it be regulated.
>>
. . . serves no useful purpose other than its use as propaganda . . . .
<<
You’re preaching to the choir Steve. When the IPCC left water vapor off of the GWP list you know it was for propaganda purposes. The GWP estimate for water vapor (they won’t tell you what it really is) is somewhere between 0.5 and 2.0. Even at 0.5, water vapor’s 4% would swamp CO2’s meager contribution. I guess that’s why they left WV off the GWP list.
Jim
Methane is short lived. Half life of 7 years. It oxidizes to CO2 and H20.
So what?
Good point. But Methane is only present in concentrations of about 0.2 ppm so I guess it doesn’t contribute much to the greenhouse effect. Anyway, if we’re no longer going to allowed to exhale, we should at least be allowed to fart. : )
CO2 might be short lived too. We don’t really know for sure. It would be cool if we could all stop using fossil fuels for a year just to see what happened. Unfortunately, that’s not practicable; most humans would starve to death.
Thomas April 28, 2017 at 2:06 pm
… Methane is only present in concentrations of about 0.2 ppm …
This link
https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4/
says it’s ~1850 ppb which averages out to 2 ppm not 0.2 ppm
So let me get this straight. All of the models up to this date have been incorrect in predicting the temperature increase of the Earth for the last quarter-century by overestimation. Now Yale discovers that the models have all been incorrect in that they should have overestimated the temperature increases even more than they did. Or are they saying that all future estimations are incorrect and that all past overestimation should be overlooked?
“All of the models up to this date have been incorrect in predicting the temperature increase of the Earth for the last quarter-century by overestimation.”
That’s not true ( http://www.nature.com/nclimate/journal/v6/n10/full/nclimate3066.html ).
The observed trend was at the low range of the models (at least until the 2014/15/16 records, I’d need to recheck now) but that’s only if you also compare models which went from negative-to-positive PDO with reality. In models where Pacific changes are similar to those observed, then the trends match up. Without human caused global warming, we would have expected to cool since 1998 instead of warm. See Risbey et al., Kosaka & Xie, England et al.
“We show that there is no evidence that climate models overestimate TCR when their output is processed in the same way as the HadCRUT4 observation-based temperature record3, 4. Models suggest that air-temperature warming is 24% greater than observed by HadCRUT4 over 1861–2009 because slower-warming regions are preferentially sampled and water warms less than air5”
“That’s not true ( http://www.nature.com/nclimate/journal/v6/n10/full/nclimate3066.html ).”
Mie – the nature article is basically stating that the models are spot on when done based on reality based science. Out of the 1,000, or so, models, how many can you point to that have reality based? More than 5%?
MieScatter
For a useful discussion of the Richardson et al paper see https://judithcurry.com/2016/06/28/towards-reconciling-climate-sensitivity-estimates-from-climate-models-and-observatiions/
joe – the non climate scientist
The Richardson et al. supplementary information is open and so is the code and data so you can check. The Supplementary Information discusses the proportion of models that are warmer/cooler than the observations over different time periods.
The Richardson et al. results use all of the CMIP5 climate model runs that have historical to 2005 plus a post-2005 scenario called RCP8.5, so the results refer to all of those.
HAS – the Richardson comparison is like-with-like, ignoring the faster-warming Arctic just like Judy implies she wants. The Supplementary Information shows that the HadCRUT4-implied response is higher than 42 % of models, lower than 58 %.
Iirc a Stevens aerosol correction implies that observations are only warmer than 30-35 % of models instead. Observations showing more warming than a third or more of the models means there’s no evidence of disagreement here.
MieScatter
And your thoughts about the circularity involving the use of GCMs in determining the sampling error estimates?
[snip – you are using a fake name, fake IP address, and fake email to troll here – banned- Anthony]
MieScatter
So we sample the models as if they were potential observations (in alternative earths) and find results from the observations don’t agree on some derived measure.
This may suggest the observations are biased (assuming the assumption was correct) but methodologically it could equally be interpreted as demonstrating the assumption that the models and observation are from the same set is incorrect. So potentially Richardson is an artifact of problems with the models rather than the observations. In other scientific disciplines this would be the default starting position for further investigation.
Also the matching of models that replicate the very recent cycles and claiming a better fit suffers from a similar theoretic problem – the assumption is being used expost – and there is also a practical one. The observations start at a temp anomaly that is low in the pdf derived from the model set and go lower within the pdf, whereas the matching PDO models start in the higher range and head below average (perhaps unsurprisingly). If you match models in the same part of the pdf as the observed temp anomaly you will find the corresponding models all trend up the pdf while the obs go down (and that no models in phase on the PDO share the same initial position in the pdf of model temps).
I think this is disastrous for the climate alarmists. This says the models must be horrifically wrong. If they put in this level of sensitivity they will have missed by incredible amounts and the 20th century “fit” they had will evaporate into a joke. This will prove the climate science so far is completely wrong.
Is MieScatter the new voice of opposition? How long before name calling and rudeness erupts? Anyone want to place bets?
I call the over/under at 17 minutes
Can I bet too? 😉
He/she seems to be avoiding ad hominem better than many here.
I wonder how he/she/it feels about polar bears – that’s the gold standard.