Global warming--models vs reality

[Flyer]

Day after day, year after year, the hole that climate scientists have buried themselves in gets deeper and deeper. The longer that they wait to admit their overheated forecasts were wrong, the more they are going to harm all of science.

When Will Climate Scientists Say They Were Wrong?

Since we can’t embed images, you’ll have to click the link to see the graph. But it’s well worth it.

[Richard_Parker]

I’m not a scientist, but even I can tell that argument is weak.

First, a model is only as good as its predicted inputs. How did CO2 emissions diverge from modeled CO2 emissions over that period, for example? I’m gonna make a wild guess that CO2 emissions grew more slowly than expected (not a wild guess, actually, since global GDP growth dipped sharply in 2007). It would be much more meaningful to retroactively plug in CO2 emissions and then see how the models hold up. Did they do that here? How would you even know from this polemic?

Second, the author doesn’t tell us how much variation the model predicted. AFAIK, what there is scientific consensus on is a range of warming given certain assumptions about CO2 emissions. This article doesn’t even bother to tell us whether the divergence it outside the predicted range.

It may well be that the models are wrong, and a smart scientist could present the missing information. But you should be skeptical of the failure to present that information.

[Lamar_Mundane]

The forecasts are for the average temperature change in the lower atmosphere, away from the confounding effects of cities, forestry, and agriculture.

Cherry picked data, in other words.

Considering 2014 was one of the three warmest global temperature years on record (maybe the warmest), I have no faith in the graph that shows it below about a half dozen recent years.

[GIGObuster]

How reliable are climate models?

While there are uncertainties with climate models, they successfully reproduce the past and have made predictions that have been subsequently confirmed by observations.

There are various difficulties in predicting future climate. The behaviour of the sun is difficult to predict. Short-term disturbances like El Niño or volcanic eruptions are difficult to model. Nevertheless, the major forcings that drive climate are well understood.

A paper led by James Risbey (2014) in Nature Climate Change takes a clever approach to evaluating how accurate climate model temperature predictions have been while getting around the noise caused by natural cycles. The authors used a large set of simulations from 18 different climate models (from CMIP5). They looked at each 15-year period since the 1950s, and compared how accurately each model simulation had represented El Niño and La Niña conditions during those 15 years, using the trends in what’s known as the Niño3.4 index.

The authors conclude,

When the phase of natural variability is taken into account, the model 15-year warming trends in CMIP5 projections well estimate the observed trends for all 15-year periods over the past half-century.

It’s also clear from the grey figure that models that are out-of-sync with the observed changes in these ocean cycles simulate dramatically higher warming trends over the past 30 years. In other words, the model simulations that happened not to accurately represent these ocean cycles were the ones that over-predicted global surface warming.

When Mount Pinatubo erupted in 1991, it provided an opportunity to test how successfully models could predict the climate response to the sulfate aerosols injected into the atmosphere. The models accurately forecasted the subsequent global cooling of about 0.5°C soon after the eruption. Furthermore, the radiative, water vapor and dynamical feedbacks included in the models were also quantitatively verified

Do we know enough to act?

Skeptics argue that we should wait till climate models are completely certain before we act on reducing CO2 emissions. If we waited for 100% certainty, we would never act. Models are in a constant state of development to include more processes, rely on fewer approximations and increase their resolution as computer power develops. The complex and non-linear nature of climate means there will always be a process of refinement and improvement. The main point is we now know enough to act. Models have evolved to the point where they successfully predict long-term trends and are now developing the ability to predict more chaotic, short-term changes. Multiple lines of evidence, both modeled and empirical, tell us global temperatures will change 3°C with a doubling of CO2 (Knutti & Hegerl 2008).

Models don’t need to be exact in every respect to give us an accurate overall trend and its major effects - and we have that now. If you knew there were a 90% chance you’d be in a car crash, you wouldn’t get in the car (or at the very least, you’d wear a seatbelt). The IPCC concludes, with a greater than 90% probability, that humans are causing global warming. To wait for 100% certainty before acting is recklessly irresponsible.

As Lamar Mundane noted, it seems that Pat Michaels is now going for the cherry picks, and this after Michaels advised the deniers to not do such a thing.

http://thinkprogress.org/romm/2009/09/06/204604/climate-crock-of-the-week-video-1998-revisited/

“You’ve all seen articles say that global warming stopped in 1998. Well, with all due respect, that’s being a little bit unfair to the data…it was a huge El Niño year, and the sun was very active in 1998…make an argument that you can get killed on, and you will kill us [skeptics] all…if you lose credibility on this issue, you lose the issue.”

Funny to see him shot himself in the foot.

[El_Kabong]

The ‘simple’ graph linked by the OP (which, by the way, is pretty vague as to what data was used to create it) was apparently generated by John Christy, a well-known but apparently not highly respected climate change skeptic.

Here is a Guardian article from February 2014 that discusses the claims of Christy and some other skeptics. About halfway down you will find a couple of graphs that are considerably at odds with what the OP has presented:

Nazis, shoddy science, and the climate contrarian credibility gap | Dana...

I’m sure there are lots of folks who really, really want to believe the skeptics’ narrative, but me, I’ll think I’ll wait to join the bandwagon until I can actually see the work on this claim.

[Sunny_Daze]

Wikipedia on WUWT

These folks seem unreliable at best, when you check into them. Their science has been repeatedly debunked (check the “Climategate” cites at the end of the article). The Weblogs closed the Science category entirely, apparently because they were rigging the vote.

Why would you take anything they publish at face value?

[Lamar_Mundane]

If they exclude water, cities, forestry, and agriculture, what exactly are they measuring? Deserts?

[GIGObuster]

@Lamar_Mundane

If they exclude water, cities, forestry, and agriculture, what exactly are they measuring? Deserts?

In the case of Christy his contrarian hammer is coming from measuring tropospheric temperatures, unfortunately humans live in the lower troposphere, but since that is not giving the result contrarians want, Christy goes higher.

Congress manufactures doubt and denial in climate change hearing

I was able to access 102 CMIP-5 rcp4.5 (representative concentration pathways) climate model simulations of the atmospheric temperatures for the tropospheric layer and generate bulk temperatures from the models for an apples-to-apples comparison with the observations from satellites and balloons ... On average the models warm the global atmosphere at a rate three times that of the real world ... As such, they would be of highly questionable value in determining policy that should depend on a very confident understanding of how the climate system works. 

Christy’s oral testimony referred only to the temperatures of the “atmosphere” and “planet.” As shown in the above quote, in his written testimony, Christy twice referenced the troposphere – the lowest layer of the atmosphere from the surface to 50,000 feet (15km) in altitude. However, to argue that climate models have been inaccurate, Christy showed a graph of only mid-troposphere temperatures. The mid-troposphere is the atmospheric layer from about 25,000–50,000 feet, or about 8–15km in altitude.

One might reasonably ask why Christy only showed data for such high altitudes. For perspective, the highest point on the Earth’s surface is on Mount Everest at 29,000 feet (8.8km), and the highest elevation city in the world is La Rinconada, Peru at 16,700 feet (5.1km). Humans live in the lower troposphere, not the mid-troposphere.

As weather balloon data show, the mid-troposphere is warming significantly more slowly than the lower troposphere, where the increasing greenhouse effect has more of an impact on temperature changes. It’s possible that climate models aren’t quite getting the vertical profile of atmospheric temperature changes quite right. It’s also possible that the measurements themselves aren’t accurate – different scientific groups have significantly different estimates of the rates of warming in the low and mid-troposphere. Some combination of both is undoubtedly true.

However, climate models have done a good job matching the observed temperature change at the surface and in the lower troposphere, where humans live. We understand the workings of the Earth’s climate much better than Christy suggests, especially where it matters most to humans.

Yep, and the article talks about the testimony that Christy made in congress very recently. He passed that wool over the eyes of the Republicans that gladly continue to rely on him. No good pickings are left specially after Willie Soon got discredited.

[Lamar_Mundane]

I wonder when, if ever, these deniers will realize they are being played for fools.

[GIGObuster]

@ddsun

Wikipedia on WUWT

These folks seem unreliable at best, when you check into them. Their science has been repeatedly debunked (check the “Climategate” cites at the end of the article). The Weblogs closed the Science category entirely, apparently because they were rigging the vote.

Why would you take anything they publish at face value?

Somehow the ones that go there do not care much that besides shoddy science and underhanded opposition to scientists they rely on Goodwins (accusing scientists and proponents of controlling emissions as Nazis). Many times, and instead of removing such trash, WUWT continues to allow nuts like Tim Ball to post there and use the controversy to get more traffic.

Anthony Watts tries for one foot in the Hitler camp and one foot out

I won’t go into the detail of the article itself. I’ll just point out that it took quite some time for Anthony to finally hint that he knows this time he’s gone way too far. Well, he’s gone too far on many occasions. However, this time he’s decided he’d better try to distance himself from the article. He’s belatedly added a tiny little post-script:

Disclaimer [added]: This post is entirely the opinion of Dr. Tim Ball, it does not neccessarily reflect the opinion of Anthony Watts or other authors who publish at WUWT. – Anthony Watts

Too little, too late. He doesn’t actually dissociate himself from the article, you’ll notice. He doesn’t say - this is most definitely NOT my opinion. All he says is that it doesn’t “necessarily” reflect his opinion. It might or might not. He’s not saying. Most certainly he doesn’t think it’s necessary to remove the article. He’d only remove an article that made him look silly even to the dumbest fake sceptic reader - like the time he posted how Greenland was completely ice free 650 years ago, and then later after he was told what nonsense it was, took the article down. Anthony only seems to be concerned about what his fake sceptic readers will think of him. Which is probably why he’s left this article up. His audience these days are more like Tim Ball than your average lukewarmer. Anthony can’t afford to alienate them.

The fact that he included “or other authors” suggests that one of his “other authors” wanted to be dissociated and told Anthony so in no uncertain terms. That’s pure speculation. There could be a clue in the comments. I haven’t read them and don’t intend to do so. There are limits.

The thing of course is that it’s Anthony’s blog. He chooses what ideas to promote and what to not. He chose to promote an article likening climate scientists to Hitler and claiming that climate scientists are engaged in some unbelievable (by any rational person) gigantic multi-decadal, global deception. He can’t dissociate himself from the article by writing that he doesn’t necessarily endorse it.

[OffByOne]

@Lamar_Mundane

I wonder when, if ever, these deniers will realize they are being played for fools.

Probably not until they are standing in sea water up to their knees.

[Euphonious_Polemic]

I found this interesting about one of the more prominent skeptics/deniers:

"Spencer is also on the advisory board of the Cornwall Alliance, a group with ‘An Evangelical Declaration on Global Warming’ claiming that “Earth and its ecosystems—created by God’s intelligent design and infinite power and sustained by His faithful providence —are robust, resilient, self-regulating, and self-correcting, admirably suited for human flourishing, and displaying His glory.” The declaration also has a section on “What We Deny,” and Spencer recently wrote in The Christian Post,

...we deny "that most [current climate change] is human-caused, and that it is a threat to future generations that must be addressed by the global community."

[cmkeller]

“Since Pinatubo the Earth has been pretty quiescent…”

Tell that to the travelers who were stranded in Europe due to that volcano in Iceland. Maybe that one had a cooling effect that needs to be figured in to the model?

[Fallen]

@Lamar_Mundane

I wonder when, if ever, these deniers will realize they are being played for fools.

I don’t think a lot of them *are *being played for fools; I think plenty recognize what’s true or likely true and simply care more about political expediency and saving face. I think instead a good many are simply pointing to whatever is handy to rationalize-justify ignoring the problem, just as is done with most problems even where there is no significant $$ to be gained personally. They certainly care about the political-power disadvantage of disagreeing with the low-information constituent. They’re no better than the average worker who would turn their head to X in order to keep a job, only on a far grander scale. I think many will never care because they won’t be alive long enough to really worry about it, and don’t care which descendants (if any) are left to deal with the fallout. As is true with humans generally, short-term self-interest is king.