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How Well Do Our Climate Models Match Our Observations?
bunratty writes "According to recent articles by Roy Spencer and John Christy, our climate models have done a poor job of predicting warming due to humans burning fossil fuels. They claim that we've observed only a fraction of the warming they predict. But when I look at the source they claim to use, the State of the Climate in 2012, I see that it shows a warming of 0.7 degrees Celsius worldwide since 1980, close to the 0.8 degrees Celsius warming predicted by the climate models. Take a look at the data for yourself. How well do our predictions match our observations?"
It's pretty easy to "predict" temperature trends in years that have already gone by.
That's because you are looking at climate models calibrated against that data that you are comparing to. Circular logic.
If you look at the predictions from past IPCC reports, very few of their predicted temperature profiles match the later observed conditions. That is a failure of the models' predictive power. That doesn't mean there isn't warming, just that the Earth's climate is a more complex system than can be accurately simulated with modern computing hardware.
It's almost as if there aren't big walls in the sky that keep emissions from leaving the countries that produce them.
Spencer has contributed specific work in peer reviewed journals that is part of the scientific discussion, but his overall opinion on climate change is motivated more by his own religion than anything else. He's both sympathetic to intelligent design and signed a statement which said among other things ""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." http://en.wikipedia.org/wiki/Roy_Spencer_(scientist)#Climate_change Essentially he believes that climate change isn't happening because his religion won't let him. Note how that statement wasn't even just about climate, but about ecosystems as a whole. Christy doesn't seem to have that same sort of underlying motivation and might make more sense to pay attention to, but in this context, the vast majority of experts disagree with both of them, and when dealing with complicated scientific issues, using expert consensus is a useful heuristic, that's before we get to the serious issue that not only is the expert consensus clear, it is a consensus about some very bad results, not just a consensus about an issue which doesn't have substantial impact.
Since it only needs 2C to drop and you get an ice age starting, I fail to see how you can claim 0.7C a minor fluctuation and wonder how it would matter.
That is a perfect example on how to misalign graphs to make them match your agenda. He should be jailed for that.
As the old song goes, little things mean a lot. You couldn't see the difference between a little botulin toxin and a lethal dose without a microscope. And I'm sure you wouldn't notice a 0.7 C difference between one room in your house and another, but multiply that amount of energy to a global scale and it starts to add up. Consider what climatologist James Hansen said about the current rate of increase in global warming: “(it's) equivalent to exploding 400,000 Hiroshima atomic bombs per day, 365 days per year. That’s how much extra energy Earth is gaining each day.”
Ask me about my sig!
Or the fact that we are still coming off of an Ice Age that lasted for more than 100,000 years, and ended less than 10,000 years ago (Or the little Ice Age that ended in 1850). Several models predict that the average temperature at the END of the last Ice Age was 15-20C lower than today.
Is global warming happening? Yes. Is the human race a contributing factor? Probably to some degree. Is the human race the only cause? No.
I can't speak to the accuracy of historic weather data or modern weather models, but I can say this:
Global Warming / Climate Change (pick one, please) alarmists do themselves an incredible amount of damage when they do the following:
1. Grossly exaggerate predictions and base everything on the worst case they can find.
2. Manipulate charts to make changes look far more significant than they really are.
3. Instantly ridicule anyone who disagrees with them on anything, even if that disagreement is valid.
Let's say for the sake of argument that all of the predictions from these weather models are 100% accurate, all of the research and data is correct, and that the climate is indeed warming because of CO2 emissions, and that the climate will warm 5 Celsius degrees in the next 200 years. Let's pretend that the science is completely perfect.
Even if all of that is true, you will find a lot of people who won't even bother listening because they remember crazy predictions like "New York city will be underwater in 20 years!" and "We're all going to be cannibals! Cannibals, I say!"
Do you see why so many people don't listen to those who are trying to push human-caused climate change?
Politics needs to be taken out of the equation. Completely. Everything needs to be 100% transparent. The science needs to be broken down in ways the average person can understand. Even if that happens, it will be decades before the damage the global warming alarmists have caused can be reversed.
Love sees no species.
China are experts on big walls, though.
The State of the Climate 2012 paper is... get this... from two years ago. After they had to start "adjusting" their models to reflect reality.
When you look at the actual historical AGW models, we're below their "optimistic" model (the one where we cut CO2 drastically over the last couple of decades - which didn't happen). And a good 0.2 C below their "probable" models.
If you're looking at predictions, go back and look at the climate models from the late 1980s and early 1990s. They're off, by a ridiculous amount.
Out of 90 models (yes, ninety), a grand total of TWO managed to predict the current temperature.
Spencer's scientific views are being affected by his religious beliefs. He is a signatory to a document called An Evangelical Declaration on Global Warming, which holds that Earth was created by "God's intelligent design" and that ecosystems are therefore "robust, resilient, self-regulating, and self-correcting". Whatever you might think of this, it is definitely not a scientific statement. Basically, he refuses to accept, for religious reasons, that humans can have an effect on the Earth's climate – in his theology, only God can do that.
Spencer is also a major proponent of the "intelligent design" scam. And both he and John Christy are based out of Alabama, one of the most backward and scientifically illiterate states in the U.S.
No scientist says humans are the only cause. There are other forcings, positive and negative. The very likely (95%-100%) in the IPCC is to the contention that "most" of the rise in temperature is caused by human forcings. Not "all".
I don't think it should be surprising if changes in climate affect the behavior of people in areas. If food becomes more plentiful I bet crime goes down. If food and water become more scarce I bet it goes up. If the weather patterns are changing surely some areas are going to get drier and some are going to get wetter. Also, as events become more extreme all the extreme weather events you sited are likely to happen more often too, don't you think? So you're right, global warming almost certainly is doing all those things.
I don't see why it's controversial to think that. Even if you don't think people have anything to do with changing climate all those effects are obvious outcomes of it changing, and I don't think many people actually doubt that it is changing.
For several years Gavin Schmidt, one of the principals of the NASA/GISS Model/E climate model, has been doing a comparison of model output to observations. There isn't an update for 2013 yet but the comparison through 2012 is available here.
Where does the 0.7C warming since 1980 figure come from exactly? I make it roughly 0.7F (note: FAHRENHEIT) from 1980 until the last point in 2012. That's an anomaly of around 0.4C, which seems to tie in with the graph on the R Spencer page.
Look back before that, the period from 1950-1974 (approximately). How well do the models match there?
Cherry picking is bad science. You have to look at the whole record from the start of the Industrial Age... and the models haven't been particularly good.
That's not an anti anthropogenic global warming statement, by the way. It's a "science is hard and you can't understand a subject after ten minutes of reading" statement.
#DeleteChrome
And yet, tree ring data from California shows that region has been in drought for something like 1600 out of the last 2000 years.
Much of it significantly *before* modern technology and CO2 pollution.
Could it be the real problem is that we don't actually know what the average temperature was before 1700?
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
Or the fact that we are still coming off of an Ice Age that lasted for more than 100,000 years, and ended less than 10,000 years ago (Or the little Ice Age that ended in 1850). Several models predict that the average temperature at the END of the last Ice Age was 15-20C lower than today.
So over 10k years temperature raised 20C, that is (20 / 10000) * 10 = 0.02C per decade, very far from 0.7 / 3 = 0.23 per decade that we see now.
I don't have sources from your numbers, and it's probably safe to assume that the rate of temperature change isn't constant either... So maybe we shouldn't try to model this at all, my calculations above are certainly as ignorant and non-sense as your postulation of numbers...
Is global warming happening? Yes. Is the human race a contributing factor? Probably to some degree. Is the human race the only cause? No.
True, there are many factors that affect the environment, but non other does it with the same speed as humans.
Global warning is primarily man-made, it's a real problem, that's the scientific consensus. And I'm fairly sure that most people on slashdot as just as qualified to discuss the scientific consensus around global warming, as soccer moms are qualified to discuss the merits and "dangers" of vaccinations.
Or the fact that we are still coming off of an Ice Age that lasted for more than 100,000 years, and ended less than 10,000 years ago (Or the little Ice Age that ended in 1850). Several models predict that the average temperature at the END of the last Ice Age was 15-20C lower than today.
Is global warming happening? Yes. Is the human race a contributing factor? Probably to some degree. Is the human race the only cause? No.
I like this game.
.002C/year. .7C over 30 years is .023C/year
Do humans have the capability to mitigate their contribution to warming? Yes. Does any other warming phenomenon? No
Do humans care if these warming effects drastically disrupt the climate that our current society has adapted to so well? Yes. Does anything else? No.
Also a quick note, 20C over 10000 years is
Just so you know: That "97 percent of all scientists in the world" silliness came from a rigged "poll."
Basically, an AGW-supporting scientist polled a number of his AGW-supporting scientist friends and co-workers - 30 or so - and asked them if they thought AGW was real.
That's where your number came from. Which should tell you something about the actual support for AGW among the scientific population at large...
They recently came up with another poll, where they cherry-picked a bunch of papers, and said "97% of scientific papers agree!" While not mentioning that only about a third of them actually addressed AGW, and they got their "new" 97% by only looking at 65 papers. Out of 12,000. Oops.
ok, so.. read through all of this page, and repeat that this is just a guy polling his friends:
http://climate.nasa.gov/scient...
I, too, used to think climategate showed all those things. I read article after article about them and how it's all over for AGW, etc. However, when taken in context, those emails actually refer to something totally other than what they were made out to refer to. I highly recommend you check out this video and this one wherein potholer54 takes an in-depth and impartial look into climategate and reveals what it actually shows... as a spoiler, it doesn't reveal that there's a giant AGW conspiracy amongst all the climate scientists in the world.
This all came out in the Climategate emails. But you never heard about those, did you?
We are well aware of release of emails from the University of East Anglia. The attempt at connecting it with watergate fails, as unlike watergate there is no smoking gun. Nothing in the emails shows any conspiracy. There is no blocking of "anti-AGW" papers. There are no "anti-AGW" papers to block. And nothing in the emails says otherwise
"Hide the decline" ring a bell?
It sure does.
"Many commentators quoted one email in which Phil Jones said he had used "Mike's Nature trick" in a 1999 graph for the World Meteorological Organization "to hide the decline" in proxy temperatures derived from tree ring analyses when measured temperatures were actually rising. This 'decline' referred to the well-discussed tree ring divergence problem, but these two phrases were taken out of context by climate change sceptics, including US Senator Jim Inhofe and former Governor of Alaska Sarah Palin, as though they referred to some decline in measured global temperatures, even though they were written when temperatures were at a record high.[32] John Tierney, writing in the New York Times in November 2009, said that the claims by sceptics of "hoax" or "fraud" were incorrect, but that the graph on the cover of a report for policy makers and journalists did not show these non-experts where proxy measurements changed to measured temperatures.[33] The final analyses from various subsequent inquiries concluded that in this context 'trick' was normal scientific or mathematical jargon for a neat way of handling data, in this case a statistical method used to bring two or more different kinds of data sets together in a legitimate fashion.[34][35] The EPA notes that in fact, the evidence shows that the research community was fully aware of these issues and that no one was hiding or concealing them.[36]"
http://en.wikipedia.org/wiki/H...
You have nothing.
Also a quick note, 20C over 10000 years is .002C/year. .7C over 30 years is .023C/year
Also worth noting is that the global temperatures didn't change 20C. The last glacial maximum was only 3C to 5C cooler than the present (http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-es.html). The height of the current interglacial period occurred about 8000 years ago. Since then temperatures have been dropping (up until recently).
"Basically, an AGW-supporting scientist polled a number of his AGW-supporting scientist friends and co-workers - 30 or so - and asked them if they thought AGW was real."
Not quite true. The original "huge consensus" rumor was started by an article (NOT a peer-reviewed paper) that appeared in Nature by one Naomi Oreskes, years ago. Oreskes claimed to have surveyed a database of science papers and concluded that none of them (not one) disagreed with the greenhouse gas global warming idea.
It was soon shown that Oreskes' "study" was in fact a textbook example of cherry-picking. She had searched the database for papers that included the phrase "global climate change". Only those were included in her analysis. The problem with that being that at the time, only papers that were ABOUT the effects of greenhouse gas warming mentioned the phrase "global climate change" at all. So, in effect, she selected out of the scientific literate just the papers about greenhouse global warming, and then conclude that they all agreed about greenhouse global warming! How surprising!
The fact was, of course, that the majority of climate papers were not about greenhouse warming and never mentioned the subject at all. But those weren't counted.
This "consensus" idea was bolstered by people claiming that almost all of the "thousands" of scientists behind the latest IPCC report had agreed about it. This, too, was a distortion of the truth. The scientists involved in the AR report at the time numbered in the hundreds. There were about 2,500 or so reviewers, and not all of those were scientists. Further, not all of them actually agreed.
Shortly after that, the Petition Project was undertaken to show that scientists in fact did not agree. Some 30,000 people with actual science or engineering credentials signed the petition DISagreeing with greenhouse global warming, and their names and professions are still publicly available at petitionproject.org. More than 9,000 of those were PhDs... far more than the 2500 who supposedly agreed, again many of whom had no advanced degrees.
Another "study" was done in this last year, which came up with that "97%" figure. Unfortunately, THAT "study" suffered from exactly the same flaw as the discredited Oreskes study: it searched the literature for papers that contained the phrase "global climate change". Self-selection at its finest.
And of course then there's the real kicker here: even if these "studies" had not been statistical nonsense, the fact remains that "consensus" is not science. If consensus were a scientifically valid measure of anything, we'd still be in the stone ages.
Or "The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't. The CERES data published in the August BAMS 09 supplement on ... shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate."
Heh, I love it when deniers mindlessly repeat that quote. You don't even know what it means, do you? Because if you did, you certainly wouldn't be mentioning it.
You see, we measure how much energy the Sun outputs. And we measure how much the Earth reflects of that energy (its albedo). We also measure how much it radiates, which - if the Earth was at a stable temperature - would be the same as the difference between the first two. Understand so far? That's what the "CERES data" refers to.
What Trenberth is saying is that the CERES data shows there should be far *more* warming than we're actually measuring! When you take into account air temperature increase, melting ice, sea temperature increase, etc etc it *still* leaves a big chunk of energy to account for. Now, any sane person would therefore assume that the energy can't just vanish: it's got to go somewhere that we aren't measuring.
Not the deniers, they think it's all being whisked away by the natural cycle fairies. Or perhaps they just don't understand what it is they're saying and are mindlessly repeating what they read on some blog. Hey, maybe you can tell us. Which is it?
Igor Presnyakov stole my hat
On a global scale, indeed: 0.7C is a small variation. The Earth has had larger variations before, and this is not unusual on a geological scale (although to be fair, its happening at a faster time scale than most of the climate changes in the past.)
However, 0.7C pretty much validates the models. If the anthropogenic greenhouse effect is not real, you need three things:
(1) You need to find an explain an explanation for why the radiative forcing does not increase temperature
(2) You need to find a hitherto-unknown effect that is causing the warming that we measure, and
(3) You need to find an explanation for why the amplifier that amplifies effect (2) to be large enough to increase the temperature doesn't also amplify the greenhouse effect. (and, contrawise, you need to explain why whatever effect it is that cancels out the greenhouse effect, (1), does not also cancel out effect (2).)
While 0.7C may be small, you should also note that we are continuing to put carbon dioxide into the atmosphere.
http://www.geoffreylandis.com
this article was published in 2009 From the abstract:
"Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers"
This study does not seem to have the flaws you mention. There have been several studies I've seen with similar outcomes.
Millions long for immortality who do not know what to do with themselves on a rainy Sunday afternoon. -- Susan Ertz
The thing is, it really doesn't matter how many scientists support it. Science isn't a democracy. See the pamphlet called 100 authors against Einstein. Einstein replied that it didn't need 100 people do disprove his theory of relativity, rather all it needed was one fact. I really hate how modern science has turned into this "if the majority believes it, it must be true." I'm sure the majority of the world still believes in creationism, but they're also still wrong.
(By the way, who decides what makes you a scientist anyways?)
Careful with names containing L slashdot.org/~AiphaWolf_HK slashdot.org/~AlphaWoif_HK slashdot.org/~AiphaWoif_HK
The IPCC's attribution graph shows the various natural and man made radiative forcing's. Without mankind's influence, most climate models predict a very slight cooling for the 20th century. Feedbacks are far more difficult to quantify however using archaeological evidence their magnitude can be inferred. Climatologists use this information to calculate a metric called climate sensitivity, this number has hardly changed since it was first derived in the 1970's. A lot of people think the IPCC is exaggerating, observation has shown that their predictions are on the conservative side (in particular the rate of melt at the north pole), cautious conservatism is what one would expect when a couple of thousand experts agree with each other.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
1) easy, CO2 is a pretty shitty greenhouse gas water is much more important.
Water is indeed a very good greenhouse gas. It also condenses out of the atmosphere, in the form of rain. Carbon dioxide does not. As a result, the amount of carbon dioxide in the atmosphere has a long-term effect. The amount of water vapor in the atmosphere, on the other hand, goes in and out of the atmosphere on a short time scale, driven primarily by the temperature-- warmer air holds more water than cold air.
The infrared absorption of carbon dioxide is measured, by the way. It's not something made up.
2) we've been coming out of an ice age for 10,000 years,
Correct-- or, more correct, we are out of the ice age.
that this remains unexplained
Fifty years ago it was unexplained. It's pretty well understood now.
leaves any "blame the humans" nonsense as laughable.
The fact that there causes of climate variation other than human input does not imply that human input doesn't also have an effect. As was pointed out, the effect is small, about 0.7C so far. But it is real.
3) no, you dont, see one and 2
The theory matches the data. If you have another theory, you have to both explain why the theory based on actual measured facts, like the absortion of infrared by carbon dioxide, isn't true, and you also have to explain why we see rising temperature anyway
like the sea rising... panicing about a few mm when in many places it changes on a meter scale every day.
Huh? I'm not panicking. I do, however, believe that it is important to not dismiss the science because you don't like the conclusions.
4) Warming is much better than cooling.
I agree. That is, however, no reason to dismiss the science.
http://www.geoffreylandis.com
If you want to assert the anthropogenic greenhouse effect is both real, and dangerous, the burden of proof is on the affirmative to come up with a necessary and sufficient falsifiable hypothesis statement which rules out natural climate change as the reason for observed temperatures.
OK. My prediction is that if you aim an infrared spectrometer at the sky, you will see downwelling infrared radiation from the CO2 spectrum.
This prediction is falsified if you don't see downwelling infrared radiation.
Hey, we see it! I win. Carbon dioxide actually does re-radiate absorbed thermal infrared. The greenhouse effect is real.
This was done over a century ago, by the way. The greenhouse effect has been known for a long time. Good thing, too; the Earth would be frozen if it didn't exist.
http://www.geoffreylandis.com
You actually wouldn't see anything, as the spectrum of water swamps most of the IR spectrum. Hydrogen bonding is funny.
Yes, in some wavelength bands all you see is the water. In others the CO2 dominates. (It also somewhat depends on whether you're lookig up from sea level in the tropics, or from temperate zones).
But, overall, if you take the spectrum (especially across the CO2 band at around 15 microns), yes, you can clearly see the downwelling IR from CO2 emission.
I could show a dozen plots for you, but here's a nice one with the big CO2 emission labelled:
http://klimakatastrophe.files....
http://www.geoffreylandis.com
->The infrared absorption of carbon dioxide is measured
its absorbtion and radiation
but more CO2 definately doesn't mean a hotter atmosphere.
Because you don't just trap more heat - you also prevent more sunlight entering in the first place.
No. Take a look at the solar spectrum some time. Almost all of the energy of incident sunlight is in a spectrum range in the visible and near IR-- peaking around one micron. The energy of the exiting infrared is in much longer infrared-- ten to twenty microns. (The fact that it's longer wavelength is Wien's law). You can have an atmosphere transparent to incident light, but absorbing to exiting infrared. This was discovered in the late 1700s.
Venus isn't hot because of the greenhouse effect, it's hot because of the enormous pressures caused by an incredibly dense atmosphere.
I'm sorry, but at this point you are revealing that you don't actually understand what you're talking about, so bye, have a nice life.
http://www.geoffreylandis.com