So aerosols caused the cooling from 1944-1974. Fair enough.
But what caused the temperature to rise quickly (nearly 0.5C) from 1910-1940 when there was an increase in CO2 levels of only 10ppm in that period?
In the past 30 years we have seen a 50ppm rise in CO2 for about a 0.6C increase in temp.
The figures do not add up.
Your theory of catastrophic warming relies not on CO2 alone but the resultant positive feedbacks from water vapour, the largest GHG. Water vapour can of course have a negative feedback through greater cloud cover and precipitation. No one really knows what is happening.
If you want people to believe you, you must provide the proof, not us who question the ‘evidence’.
[Response: Perhaps you could point me to the section in the IPCC report where it says that CO2 is the only forcing and that there is no unforced variability in temperatures? While we’re waiting, I’d like to point out that it isn’t scientists’ jobs to prove to you strawman statements that they’ve never made. – gavin]
Facts out of context. Gee, that was easy. Essentially, the gist of the page is a pile of red herrings. Add rye bread and some cheese and you’ve got some snacks but no relevant perspectives on the science in accord with the ridiculous arguments as presented.
Think of it this way: Humans did not exist while dinosaurs walked around on the planet.
Also, our modern civilization and infrastructure has been built in accord with a particular climate, around thermal equilibrium, in the most recent 10,000 years.
Now we have added a significant amount of forcing.
That means moving and changing infrastructure. How rich are you?
simon abingdonsays
#793 Brian Brademeyer
“So reduced cooling clearly doesn’t equate to warming! Nominated for 2009 Howler of the Year!”
That’s right Brian, reduced cooling (like in a Thermos Flask perhaps) doesn’t equate to warming. Did you think it did?
Perhaps I should nominate “So reduced cooling clearly doesn’t equate to warming! Nominated for 2009 Howler of the Year!” for “2009 Howler of the Year!”?
[Response: No. Everyone is discussing temperature anomalies. Warming or cooling relative to some other situation. Using a blanket keeps you wamer than you otherwise would be, GHG, nighttime clouds – or high clouds at any time – keep the planet warmer than it otherwise might be. Please try and go back to arguing about something vaguely interesting. – gavin]
caerbannogsays
#795 Timothy Chase: “But the hypothetical snowball earth would have been much earlier than the Cretaceous — which was 206-144 million years ago.”
I’m sure that you meant 145-65MYA for the Cretaceous. Didn’t really want to nitpick here — just wanted to deny Dowden the opportunity to jump all over a “thinko” in an attempt to discredit your reply.
Matthewsays
796, Ray Ladbury
From the second of your two links: ver a twenty year period, you would be on stronger ground in arguing that a negative trend would be outside the 95% confidence limits of the expected trend (the one model run in the above ensemble suggests that would only happen ~2% of the time).
And after 10 more years of the non-warming, we shall have a better appreciation of which of the models might be correct, and whether they are all wrong in important ways. According to AGW, what is the explanation for the lack of warming of the last 10 years or so, random variation? Trenberth rather bemoaned the lack of an explanation. Does AGW predict that the resumption of the trends of 1855-1885 (appx), 1915-1935 (appx) and 1977-1997 (appx) will occur randomly?
Edward Greischsays
775 Andrew Hobbs: Benzene is a far more potent cancer causer. Benzene is found in petroleum and coal. I bet on benzene as the cause of those cancers. Radiation doesn’t cause cancer efficiently. If you want a guinea pig to get cancer, you paint it with benzene, NOT irradiate it.
Background radiation is the ionizing radiation from several natural radiation
sources: sources in the Earth and from those sources that are incorporated in our
food and water, which are incorporated in our body, and in building materials and
other products that incorporate those radioactive sources; radiation sources from
space (in the form of cosmic rays); and sources in the atmosphere which
primarily come from both the radon gas that is released from the earth’s surface
and subsequently decays to radioactive atoms that become attached to airborne
dust and particulates, and the production of radioactive atoms from the
bombardment of atoms in the upper atmosphere by high-energy cosmic rays.
Since 1945 it also comes from low levels of global radioactive contamination due
to nuclear testing.
Contents
Natural background radiation comes from three primary sources: cosmic
radiation, terrestrial sources, and radon. The worldwide average background dose
for a human being is about 2.4 mSv per year [1] (pdf). This exposure is mostly
from cosmic radiation and natural isotopes in the Earth.
Cosmic radiation
The Earth, and all living things on it, are constantly bombarded by radiation from
outside our solar system of positively charged ions from protons to iron nuclei.
This radiation interacts in the atmosphere to create secondary radiation that rains
down, including X-rays, muons, protons, alpha particles, pions, electrons, and
neutrons. The dose from cosmic radiation is largely from muons, neutrons, and
electrons.
The dose rate from cosmic radiation varies in different parts of the world based
largely on the geomagnetic field and altitude.
Terrestrial sources
Radioactive material is found throughout nature. It occurs naturally in the soil,
rocks, water, air, and vegetation. The major radionuclides of concern for
terrestrial radiation are potassium, uranium and thorium. Each of these sources
has been decreasing in activity since the birth of the Earth so that our present
dose from potassium-40 is about 1⁄2 what it would have been at the dawn of life
on Earth. Some of the elements that make up the human body have radioactive
isotopes, such as potassium-40, so there is also a very small amount of internal
radiation.
Radon
Radon gas seeps out of uranium-containing soils found across most of the world
and may concentrate in well-sealed homes. It is often the single largest
contributor to an individual’s background radiation dose and is certainly the most
variable in the United States. Many areas of the world, including Cornwall and
Aberdeenshire in the United Kingdom have high enough natural radiation levels
that nuclear licensed sites cannot be built there—the sites would already exceed
legal radiation limits before they opened, and the natural topsoil and rock would
all have to be disposed of as low-level nuclear waste.
Artificial “background” radiation
Every above-ground nuclear detonation scatters a certain amount of radioactive contamination. Some of this contamination is local, rendering the immediate surroundings highly radioactive, while some of it is carried longer distances as nuclear fallout; some of this material is dispersed worldwide. Nuclear reactors may also release a certain amount of radioactive contamination. Under normal circumstances, a modern nuclear reactor releases minuscule amounts of radioactive contamination. However, reprocessing plants released waste, including plutonium, directly into the ocean. Major accidents, which have fortunately been relatively rare, have also released some radioactive contamination into the environment; this is the case, for example, with the Windscale fire (Sellafield accident) and the Chernobyl accident.
The amount of radioactive contamination released by human activity is rather small, in global terms, but the radiation background is also rather low. Some sources claim that the Earth’s background radiation level has tripled since the beginning of the twentieth century. In fact, the total amount of radioactivity released by man is inconsequential to the large quantities of radioactivity in the natural environment [2] (pdf).
Artificial radiation sources
The radiation from natural and artificial radiation sources are identical in their nature and their effects. These materials are distributed in the environment, and in our bodies, according to the chemical properties of the elements. The Nuclear Regulatory Commission, the Environmental Protection Agency, and other U.S. and international agencies, require that licensees limit radiation exposure to individual members of the public to 100 mrem (1 mSv) per year, and limit occupational radiation exposure to adults working with radioactive material to 5 rem (50 mSv) per year, and 10 rem (100 mSv) in 5 years.
The exposure for an average person is about 360 millirems/year, 80 percent of which comes from natural sources of radiation. The remaining 20 percent results from exposure to artificial radiation sources, such as medical X-rays and a small fraction from nuclear weapons tests.
Other usage
In other contexts, background radiation may simply be any radiation that is pervasive. A particular example of this is the cosmic microwave background radiation, a nearly uniform glow that fills the sky in the microwave part of the spectrum; stars, galaxies and other objects of interest in radio astronomy stand out against this background.
In a laboratory, background radiation refers to the measured value from any sources that affect an instrument when a radiation source sample is not being measured. This background rate, which must be established as a stable value by multiple measurements, usually before and after sample measurement, is subtracted from the rate measured when the sample is being measured.
Background radiation for occupational doses measured for workers is all radiation dose that is not measured by radiation dose measurement instruments in potential occupational exposure conditions. This includes both “natural background radiation” and any medical radiation doses. This value is not typically measured or known from surveys, such that variations in the total dose to individual workers is not known. This can be a significant confounding factor in assessing radiation exposure effects in a population of workers who may have significantly different natural background and medical radiation doses. This is most significant when the occupational doses are very low.
United Nations Scientific Committee on the Effects of Atomic Radiation
UNSCEAR 2000 Report to the General Assembly,with scientific annexes
Volume I: SOURCES
CONTENTS:
Report to the General Assembly
(without scientific annexes;17 pages)
Includes short overviews of the materials and conclusions contained in the scientific annexes
How do you know those cancers were caused by Chernobyl?
Timothy Chasesays
Gavin and all,
I had stated yesterday regarding your imminent 10,000,000 visitors since 2004 in comment 711:
I might prefer New Years Day if for nothing else than the toasting of what is past, present and yet to come, but it is looking like it will be a very Merry Christmas….
Congratulations!
I stayed up until 3:00 AM PST, and at that point you were shy of 10,000,000 by roughly 1,500 unique hits, so it would appear you did not make it in time for Christmas in any time zone. However, only a couple of months ago you were at less than 9,000,000 hits since December 2004, so it would appear that Real Climate is being looked to more than ever before for an understanding of what confronts humanity. And I would suggest that 10,000,000 will mark a very auspicious beginning to 2010!
Radge Haverssays
@756
” This is exactly the sort of snarkiness that has no place in science *or* serious politics.”
Oh great. A lecture on tone from the guy who arrived announcing himself as a “full blown scoffer,” boasted about his credentials outside of climate science, and blithely dismissed AGW with a wave of his finger, a little bit of jargon and some tired accusations about dogma, kool-aid, and denigrating the opposition — all with absolutely no sense of irony.
Like we’ve never seen that before.
Holy moly.
Matthewsays
796, Ray Ladbury
tamino did it one way. If you do a statistical analysis that allows for “change points” or “switching regressions”, as documented in the econometrics literature and statistics literature (theoretical analyses) and recently published in the peer-reviewed literature (for temperature), there is a statistically significant change somewhere in 1998-2000. Tamino used a statistical technique with very low power to detect a change, should such a change exist.
captdallas2 — What about “climate shock” do you need tht cannot be found in “The Discovery of Global Warming” by Spencer Weart, first under Science Links on the sidebar?
simon abingdonsays
#792 Ray
“If the system is warming, it can mean that Energy_in is increasing or that Energy_out is decreasing”.
Ray, I have a problem with that.
If for example Energy_in is zero and Energy_out is decreasing the system cannot be warming. It’s just cooling more slowly. You need Energy_in to be greater than Energy_out for warming to happen.
Or maybe I’m using words wrongly.
If you can sort me out on that I’ll be ready for the rest of your explanation to my #777.
dhogazasays
According to AGW, what is the explanation for the lack of warming of the last 10 years or so, random variation?
Walter Manny, OK, I’m a little confused here as to what your proposal is. We have a threat here, the effects of which could be disastrous. You admit that the consensus theory of Earth’s climate is the best model (in fact the only model) we have today. The theory–and it is an extremely successful theory–says that if we keep going down the path we are on, we could face very severe consequences, but that if we limit our CO2 emissions, we ought to be able to avoid the worst of those consequences. So what should we do? Should we follow the counsel of what the best scientific model of the climate model tells us, or should we do the exact opposite? Those are the choices, right?
Now, you say we might have a better model in the future. OK, but how do we make policy based on a model we don’t have now? In particular, even if we were going to get a better model, how likely do you think it is that it would dismiss CO2 to the level of unimportant player in Earth’s climate? Yes, Trenbreth and others express frustration at our inability to model short-term influences. That’s his job–to motivate people to come up with better models. We’ve had posts on that here at RC? That doesn’t invalidate the role of CO2, which is a long-term influence. Do you think that David Hilbert was indicting all of mathematics when he proposed his list of unsolved problems at the beginning of the last century.
As to sensitivity, I find it rather remarkable that 10 independent lines of evidence all favor a sensitivity of 3 degrees per doubling:
It looks like a pretty consistent trend to me. In any case, if 2010 were a big El Nino year and suddenly we had another record, would all your doubts about AGW vanish?
We can either go with the counsel of science or we can go against it. Science or anti-science. There’s no middle ground.
simon abingdonsays
#805 Gavin’s response
“Using a blanket keeps you warmer than you otherwise would be, GHG, nighttime clouds – or high clouds at any time – keep the planet warmer than it otherwise might be. Please try and go back to arguing about something vaguely interesting. – gavin”
The sun is the only significant agency that heats the Earth. If things changed and one side of the Earth remained perpetually in darkness, that side’s temperature would fall inexorably towards zero K, more slowly in the presence of GHGs of course, but down nonetheless. If you (and climate science generally) call this a warming effect it may explain why I sometimes find you hard to understand.
Ray Ladburysays
Ian George, the warming from 1910-1944 is not as well understood as we would like. However, there were several known factors at play:
1)Increased insolation
2)decreased volcanic activity
3)increased greenhouse heating
Remember that warming due to ghg had been masked in the period from 1944-1974. Once clean air legislation removed the aerosols, the atmosphere warmed rapidly. CO2 is a continual forcing. It is not that temperature is proportional to CO2, but rather that increasing CO2 takes a bigger bite out of the outgoing IR flux, and the globe must warm up more and emit more IR as a consequence to reach equilibrium again. We’ve got the evidence. It’s up to you to learn the science so the evidence will make sense.
#795 Timothy Chase: “But the hypothetical snowball earth would have been much earlier than the Cretaceous — which was 206-144 million years ago.”
I’m sure that you meant 145-65MYA for the Cretaceous.
You give me a little to much credit: I am a philosophy major turned computer programmer, not a paleoclimatologist, and as such I really don’t have the time frames memorized.
… the last time we would have been as high as 2000 ppmv of CO2 would have been 200 million years ago, which coincidentally would have been very early Jurassic. The configuration of the continents would have been decidedly different, and likewise the climate sensitivity.
As such it really doesn’t affect the argument, likewise, just as you thought. But it would seem to suggest that both Blair and I have some additional studying to do.
Ray Ladburysays
OK, Simon, work with me here. Try to concentrate. I started with considering a system at equilibrium–Energy_in=Energy_out. In such a system if Energy_in=0, then Energy_out must equal zero, no. So Energy_out cannot decrease below zero, right? In fact, it can’t even equal zero in a real system.
And wrt your comment to Gavin about a planet where it’s nighttime 100% of the time, I’m sorry, but we were under the impression that we were talking about Earth rather than your planet. Also, as long as there is a fluid atmosphere, it will carry heat around to the other side, and eventually, you will have so much water ice, frozen CO2, etc. that your planet will tilt it’s axis in any case.
Doug Bostromsays
simon abingdon says: 26 December 2009 at 3:47 PM
“The sun is the only significant agency that heats the Earth. If things changed and one side of the Earth remained perpetually in darkness, that side’s temperature would fall inexorably towards zero K, more slowly in the presence of GHGs of course, but down nonetheless.”
Yeah, well that’s not reflective of actual conditions here, hmmm? I was totally confused about the point you’re trying to make, until I scanned back a few posts and realized that you don’t seem to know how a signal can be affected by noise. The signal of interest here is AGW forcing, the uninteresting signal is unforced variation. If you don’t know what those mean, why are you wasting your glucose with thought experiments about a tidally locked Earth when you’ve got such fundamental homework to do?
Ray Ladburysays
Matthew,
If you take a sufficiently complicated model, you can fit any data. That is why Occam’s razor is so important–or equivalently, you could use AIC. There is absolutely no physical reason given for assuming shifts in the data. Moreover, since they are modeling data with a pretty strong auto-correlation, I’d say they are on extremely shaky ground assuming such a complicated statistical model. Sorry, I’ll stick to physics rather than mere curve-fitting.
Blair Dowdensays
Re #795: Timothy, sorry if there was some confusion between the two separate examples of the Cretaceous and Snowball Earth eras. And contrary to certain paranoia here, I am not going to jump on minor errors.
Lets stick to snowball earth. Since we are talking in very round numbers, I don’t have much trouble with your analysis. I get four doublings of CO2 from pre-industrial levels to get to 16 W/M2, but a doubling of CO2 is a bit less than a 2% change in the solar constant. So Hansen’s proposed forcing to get a runaway greenhouse is something like a factor of three short of what occurred after the snowball earth episodes. This does not really support his argument, although it is not as bad as I first thought.
I do take issue with the climate sensitivity arguments. The high CO2 levels are reached before the ice starts melting. With the ice gone you are going to get a lot of evaporation and a large water vapor feedback (a fast effect), as well as increased absorption by the ocean and land weathering (slower effects).
I am not suggesting it is a good idea to force the climate to Cretaceous levels. This might be a little disruptive to our agriculture, not to mention 70 m of sea level rise. There are many good reasons to prevent greenhouse gas levels from getting anywhere near this level. I object to suddenly declaring a runaway greenhouse effect, which seems to be based only on a model that was not designed for those conditions, and some hand waving. A scientist should not be making scientific statements that are not backed by proper research and peer review. I consider this to be irresponsible and unnecessary; it discredits the reputation of climate scientists in general.
Finally, to undermine my own analysis, I do not understand why the snowball earth hypothesis relies only on carbon dioxide from volcanoes to reverse the process. Surely the same volcanoes would deposit ash on the snow, and in a world with no evaporation, thus no weather, the albedo would continue to decrease and cause melting before CO2 got to such extreme levels. If the hypothesis takes this into account, I have not heard it mentioned.
dhogazasays
tamino did it one way. If you do a statistical analysis that allows for “change points” or “switching regressions”, as documented in the econometrics literature and statistics literature (theoretical analyses) and recently published in the peer-reviewed literature (for temperature), there is a statistically significant change somewhere in 1998-2000. Tamino used a statistical technique with very low power to detect a change, should such a change exist.
So go over there and confront him on his own turf.
Don’t let the fact that he’s a professional statistician who analyzes time series for a living keep you from proving him wrong …
For the calculation, the CO2 records from Fig. 1D are used and solar luminosity is assumed to linearly increase starting at 94.5% present-day values. Values are expressed relative to pre-industrial conditions (CO2 = 280 ppm; solar luminosity = 342 W/m2); a reference line of zero is given for clarity.
Note to figure 2, pg. 5668 of Royer DL. 2006. CO2-forced climate thresholds during the Phanerozoic. Geochimica et Cosmochimica Acta, 70: 5665-5675
… with the beginning of Phanerozoic ~575 mya having a solar luminosity of 94.5% what we have today and assuming that solar luminosity has change more or less as a linear function of time, 200 mya would have seen a solar luminosity ~1.9% lower than it is today.
dhogazasays
Oh, Matthew, Matthew, Matthew, the site you link starts off saying …
…They point to their complex and error prone general circulation models that, after significant re-factoring, are now predicting a stretch of stable temperatures followed by a resurgent global warming onslaught.
…
Which is an outright lie.
You really expect any of us to read further after encountering that?
to Sean @ #508, who asked about details of the peer review process…
the process is slightly different from journal to journal (and, I expect, from
field to field too). as John E. Pearson said earlier, the journal editor(s) will typically attempt to recruit reviewers who are familiar with the subject matter discussed in a newly submitted paper. most journals in the atmospheric sciences ask authors to recommend 3 or 4 potential reviewers (though I have no clue how often the editors actually act on these recommendations). when an invitation to review is sent out, prospective candidates are asked to decline if they believe they cannot provide an objective review.
the degree of effort put into a review can vary widely, and in general a reviewer’s comments are not available outside the journal’s editorial staff. one exception to this is Atmospheric Chemistry and Physics, which is a highly regarded “open access” journal that publishes submitted papers and reviews on-line. a complete description of the ACP’s Review Process, including manuscript evaluation criteria and the obligations for reviewers, is available at their website. the reviews themselves are posted online, so that you (and anybody else too) can download and read as many as you want simply surfing over to the ACP’s papers in open discussion section. in my experience, the quality and thoroughness of the reviews posted at ACP are representative of the reviews given for other atmospheric sciences journals.
Matthewsays
817, Ray Ladbury: Ian George, the warming from 1910-1944 is not as well understood as we would like. However, there were several known factors at play:
1)Increased insolation
2)decreased volcanic activity
3)increased greenhouse heating
Isn’t the same true of the warming from 1855-1885, and the cooling that is identified as the Little Ice Age, and the warming that is identified as the Medieval Warm Period? That is to say, many known and hypothesized causes (Maunder Minimum for the LIA, to name just one), without a thorough understanding of the strengths of all?
Here is my answer to a question that is sometimes posed: In order for me to stop being a skeptic, I would need to see some more decades of warming like 1977-1997; in the mean time, we should have some prudent preparations, but not try to re-organize the energy economies of the developed nations and BRIC nations. In the US, replace coal with natural gas, for example, and continue to develop biofuels (including algal based) and carbon sequestration and storage. It would be a shame if the world invested in reduced warming and then experienced another little ice age because of the sun’s apparent reduced activity lasting decades. The solar theories are not “better than” AGW, they have problems of their own.
Daniel J. Andrewssays
Walter Manny @769 said,
I especially love the conspiracy bit, that denialism is somehow an industry, that anyone who does not buy the RC line in is some stooge in thrall to the oil-funded scientists sitting around our homes.
Or you could say…
I especially love the conspiracy bit, that denialism is somehow an industry, that anyone who does not buy the M.D. line in is some stooge in thrall to the tobacco-funded scientists sitting around our homes.
It isn’t a conspiracy. The links between global warming denial and industry are well documented just as they were for the tobacco and cancer denialism.
Funding was given to think-tanks and politicians with the express purpose of making the public think there was some debate among those researching climate change (and among those researching tobacco and cancer). You and your friends may not be funded by oil, but pretty much every misconception you have can be traced back to think-tank distortions and lies.
Some of the same people and think-tanks promoting confusion and denial about global warming were involved in promoting confusion and denial about smoking, as well as about asbestos, CFCs, and acid rain. Same playbook, same tactics, different cause.
See Naomi Oreskes presentation American Denial of Global Warming
youtube.com/watch?v=2T4UF_Rmlio
and browse the database and articles at the desmogblog.com, and follow their links to original sources like Exxon’s own budgets, memos, etc.
Walter Manny, OK, I’m a little confused here as to what your proposal is. We have a threat here, the effects of which could be disastrous. You admit that the consensus theory of Earth’s climate is the best model (in fact the only model) we have today. The theory–and it is an extremely successful theory–says that if we keep going down the path we are on, we could face very severe consequences, but that if we limit our CO2 emissions, we ought to be able to avoid the worst of those consequences. So what should we do? Should we follow the counsel of what the best scientific model of the climate model tells us, or should we do the exact opposite? Those are the choices, right?
Ray, it is absolutely the case that I cannot find another, better model than what comprises the consensus model at the moment. Obviously, that does not mean the consensus model is correct, though it is of course enormously appealing to our chronocentric minds to believe otherwise.
“Chronocentric” minds?
It would appear that Walter Manny has been dipping into Kant’s transcendental idealism again! (please see: Section 15: The Two Selves, Something Revolutionary) which I would argue is either self-referentially incoherent (Section 24, ibid.) or engages in widespread circular reasoning (please see: Section 29: Transcendental Idealism’s Primary Line of Defense, ibid.).
Personally I would much rather go with Ray Ladbury, the scientific consensus, and the best that empirical science currently has to offer — even if Walter and Kant would regard this as a subjective preference on my part.
How can I respond to the people who criticize AGW on the grounds that data and software code are not public? I am aware that some data is proprietary, but is code withheld? If so, what is the reason for that?
816 Simon A wrote The sun is the only significant agency that heats the Earth. If things changed and one side of the Earth remained perpetually in darkness, that side’s temperature would fall inexorably towards zero K, more slowly in the presence of GHGs of course, but down nonetheless. If you (and climate science generally) call this a warming effect it may explain why I sometimes find you hard to understand.
————-
Is this just a matter of semantics for you? If clouds in the night keep heat from being lost, then the next day, the heating starts from a slightly higher point, hence the nightime clouds help the OVERALL warming, although should they stick around during the next day, they would cause RELATIVE cooling, even as the temperatures rose.
I think that your issue is the insistence that a lack of cooling cannot be considered the same as warming, but can you see that the overall effect is warming?
BFJsays
Testing AGW.
Ray Ladbury : If we were to observe no warming for 20 years, it would certainly indicate that our theory was missing something. It would not, however, negate the known greenhouse properties of CO2 as a well mixed, long-lived greenhouse gas.
Sure; but OK, I get that you are also prepared to look at evidence. The question, it seems to me, is not so much just what CO2 is doing, but figuring what out the other (unknown?) factors are doing – the ones that presumably overwhelmed the presumed CO2 effect to give us a net result of no warming for the last eight or so years. What are these factors, and why did they change in about 2002?
I do think Cap & Dividend would make a great topic. Would need to get an economist or two involved for the item. Justification is that science directly relates to policy consideration. In fact that is largely why governments fund science, for the public good.
My Dec. Leading Edge Report was dedicated to this issue.
We pretty much knew they would produce a non binding agreement at COP15 months ago. That might prove to have been a good thing. It gives us a little time to education on ‘cap and trade’ v. ‘cap and dividend’.
In other words an RC article on Science and potential implications for economy in relation to policy choices. I know it’s complex but I think this is a good idea. Anyone else?
Ray Ladburysays
Matthew @828, of course the data we have become more sparse and less reliable the further we go back in time. Prior to the invention of the telegraph, it would have certainly been conceivable to have a large volcanic eruption in a sparsely inhabited part of the world without knowing it. ENSO is a relatively new discovery. The world prior to 1957 is vastly different in terms of how well we could observe it compared to the present. So the fact that there are a few epochs we cannot entirely understand does not detract from the successes of the current model.
And the problem is that we may not have another two decades to waste reverifying known physics. If we trigger large natural sources of CO2 and CH4, we won’t have the option of reducing greenhouse emissions via our own activity.
And your assumption that we can continue business as usual for a couple of more decades is simply not tenable. We don’t have enough natural gas to fuel growth in the BRIC countries, let along to fuel development if the rest of the third world reaches economic takeoff (as we hope they will). The global energy economy is simply not sustainable, even of anthropogenic CO2 were not an issue.
Matt, climate science has already been subjected to unprecedented scrutiny. Not only have the basic tenets of the theory passed 50 years of peer review and exhibited tremendous explanatory and predictive skill, it has also survived exceptional external scrutiny. National Academy panels, professional organizations of scientists in related fields, congressional committees, DOD, DOT, Foreign government agencies… Panels with impeccable credentials and integrity have looked at the evidence and the science and not one has dissented from the consensus science. Not one! Even the theory of evolution has never been subjected to this level of scrutiny! Sorry, Matthew, we can’t wait just because YOU don’t understand the evidence or science yet.
simon abingdonsays
#819 Ray
OK Ray, I’m trying really hard.
You said (#792) “Constant temperature is a sign of a system at equilibrium–that is Energy_in=Energy_out. If the system is warming, it can mean that Energy_in is increasing or that Energy_out is decreasing”
Although you started with constant temperature you then said “if the system is warming…” (That’s not constant temperature any more is it Ray?) “…it can mean that Energy_in is increasing or that Energy_out is decreasing”. And I said (#813) “If Energy_in is zero and Energy_out is decreasing the system cannot be warming. It’s just cooling more slowly. You need Energy_in to be greater than Energy_out for warming to happen”.
Ray, does Warming mean Increasing Temperature, or not? Because it does in the world of ordinary people.
(BTW my Oxford graduate scientist daughter has just confirmed that warming requires the input of some sort of energy. Naturally I’m inclined to believe her).
And you said
Spaceman Spiffsays
Continuing my post #783 (re. effects of clouds):
simon abingdon@#791 had a question regarding the role of high thin clouds being net positive radiative forcings. The simple reason is this: they are largely transparent to most of the Sun’s spectrum (and so letting in much of the energy from the Sun), but are still black to much of the IR emitted by Earth’s surface.
fragmentsays
I was just referring to someone to an old post ( https://www.realclimate.org/index.php/archives/2007/04/learning-from-a-simple-model/ ) and noticed that latex seems to have disappeared, rendering the math notation difficult to read. The archived posts are really useful resources, it would be great if you could manage to get the notation working again.
simon abingdonsays
#820 Doug Bostrom
“why are you wasting your glucose … when you’ve got such fundamental homework to do?”
I’m trying to do it. At the moment I’m struggling with the bizarre notion that in climate-science-speak “warming” doesn’t only mean “increasing in temperature” but can also mean “cooling (decreasing in temperature) but not so rapidly as otherwise expected”. I find this usage altogether confusing.
Walter Mannysays
Ray, I’m sorry but I reject your premise: “The theory – and it is an extremely successful theory – says that if we keep going down the path we are on, we could face very severe consequences, but that if we limit our CO2 emissions, we ought to be able to avoid the worst of those consequences.”
What is successful in the extreme about this theory? If it were so extremely successful, the smart folks you mention (the ones who are wrong) would not object to it, or they would not, in fact, be as smart as you say. I mean, hell, if my theory predicts temperature rise, I have a one in three chance of being right. You make it sound as though CO2 and global temperature were walking hand in hand down some Yellow Brick Graph.
What is extreme, however, is the extent to which you would need to change the world to limit the CO2 to the degree purportedly necessary to avoid the “very severe consequences” you fear. Surely that ship has sailed? Do you still believe that pounding the CO2 drum will ever bring down the rate of its growth, let alone reverse it? I suppose it could, but these Copenhagens are getting increasingly embarrassing.
Incidentally, I’m not referring to Trenberth’s frustration with short-term models. I’m referring to his frustration with short-term [and long-term] observations. “We’ve always had some problems with the observing system.”
Re #795: Timothy, sorry if there was some confusion between the two separate examples of the Cretaceous and Snowball Earth eras. And contrary to certain paranoia here, I am not going to jump on minor errors.
Perhaps when caerbannog suggested you might he was reacting to your use of the term “alarmism” which with me resulted in the association with “alarmists.” Those who use that term are usually the sort that would jump on minor erros.
I do take issue with the climate sensitivity arguments. The high CO2 levels are reached before the ice starts melting. With the ice gone you are going to get a lot of evaporation and a large water vapor feedback (a fast effect), as well as increased absorption by the ocean and land weathering (slower effects).
Water evaporation would have been a fast feedback — but the solar constant would have been closer to 98% of what it is now, not 99%, much of the heat would have gone into the melting of the ice, not evaporation at least for a while (although there would have been increasing sublimation — doubling for each additional 10°C above -40°C), and as I pointed out, much of the carbon dioxide would have been taken up by an ocean where the difference in partial pressure between the ocean and the atmosphere would have presumably been much greater than it is today. Furthermore, the partial pressure of water vapor wouldn’t have increased dramatically above today’s levels in reaction to higher temperatures until most of the ice had melted — and by that time the climate sensitivity that we would be dealing with would be much lower — since most of the ice had melted, exposing dark ocean and rock. The main feedback which would have been an issue during the early part of the transition from icehouse to hothouse would have been due to the albedo effect, not water vapor.
Furthermore, currently only about half of the carbon dioxide that we emit is left in the atmosphere after the first year that it is emitted. However, this is because much of that carbon dioxide is absorbed by the ocean — which wouldn’t come into play until the ice covering the ocean began to thaw to reveal the water beneath it. Furthermore, currently, if we were to stop adding carbon dioxide to the atmosphere, assuming a large slug (4,000-5,000 Gton), one third of what is left of the carbon dioxide added to the atmosphere would be taken up by the ocean within the first one thousand years.
Now admittedly the slug we are talking about in the case of snowball earth is much greater, but then again, in the case of the 5,000 Gton slug added to today’s earth we are talking about an ocean that started out at equilibrium with the atmosphere, not one in which the ocean was heavily depleted of carbon dioxide.
In either case, a strict snowball earth is itself somewhat controversial. There are suggestions that a slushball earth is much more realistic in which case such high levels of atmospheric carbon dioxide would not have been required to result in a transition to a hothouse.
Finally, to undermine my own analysis, I do not understand why the snowball earth hypothesis relies only on carbon dioxide from volcanoes to reverse the process. Surely the same volcanoes would deposit ash on the snow, and in a world with no evaporation, thus no weather, the albedo would continue to decrease and cause melting before CO2 got to such extreme levels. If the hypothesis takes this into account, I have not heard it mentioned.
I honestly do not know. Something worth digging into.
Steve Fishsays
Comment by simon abingdon — 26 December 2009 @ 3:31 PM:
You said– “If for example Energy in is zero and Energy out is decreasing the system cannot be warming. It’s just cooling more slowly.”
You have also suggested similar reasoning in subsequent posts, but on a cloudy day the atmosphere still warms, just not as much as on a clear day. There is not zero input through clouds, and the clouds keep more heat in both during the daytime and nighttime. A simple example is an arbitrary clear sky day in the desert that is 90 degrees in the daytime and 40 at night, averaging 65. Compare this to a very cloudy day in northeastern Ohio that is a cooler 80 degrees during the day but only decreasing to 50 at night, so the average would also be 65 degrees. The point is that clouds damp the large day/night swings in temperature, and the question is– what is the net influence. Research suggests that it is slightly positive.
This is a simple concept and I don’t see why you don’t get it. In fact I believe that you do and your continuing obfuscation is deliberate. Perhaps this is your hobby.
Steve
Steve Fishsays
Comment by Matthew — 26 December 2009 @ 3:24 PM:
The Stockwell and Cox analysis might have been more convincing if they had also identified the rather obvious break and shift between about 1950 and 1975, for which there is a known cause. They should have first tested the technique by applying it, blind, to several randomly selected temperature series’ from the past in order to be convincing.
Steve
Spaceman Spiffsays
Matthew @#828 says:
“It would be a shame if the world invested in reduced warming and then experienced another little ice age because of the sun’s apparent reduced activity lasting decades.”
Well, if we were to begin entering a ~1 century phase of another “little ice age”, we’d already have quite a buffer built into the pipeline, and those who understand the role of CO2 as a radiative forcing agent would know what to do then, right? But more seriously,…
The earth’s climate is a huge non-linear system. If perturbed gently, it behaves quasi-linearly albeit with delays in equilibrating. These delays aren’t hard to deal with, as long as the disturbances are small. We can do so in principle by reducing the C02 and CH4 that we pump either directly or indirectly into the atmosphere. What we cannot deal with is moving the Earth’s climate far enough away from equilibrium that it enters the strongly non-linear regime, whereupon positive radiative forcings begin reinforcing each other, sources of C02 and CH4 are dumped into the atmosphere and sinks thereof become ineffective. This scenario has happened in Earth’s distant past, as paleoclimatologists and paleogeologists will tell you (and there weren’t 7 billion humans then). Not only are the relatively rapid accumulative effects far beyond our means of control, but their rapidity means that these will be gifts that will keep on giving (and growing) because the Earth takes too long to equilibrate.
As for betting on the uncertainties — what we know of Earth’s climate, what we have been and are doing to it, and some of the potential consequences is far greater than we know what the Sun is or might be doing over the same time scale. The 11-year sunspot cycle, with its variability and probable accompanying changes in total solar irradiance, is akin to short-term weather, as regards to the Sun. (I am an astronomer by profession.)
Brian Dodgesays
Simon Abingdon, and any one else who wants to do a simple science experiment.
go to your local House Of Fraser/WalMart/kitchen shop and get two meat thermometers. Get a 50 x 2400 x 1200mm/2″x4’x8’foam insulation board from Wickes/Home Depot/DIY homebuilders shop. Stick the two thermometers into some flat exposed ground 2m/6ft/2 paces apart. leave them exposed during 4 or more successive days of clear weather, but cover one of the thermometers at night with the foam insulation. Record the temperatures of both thermometers every morning and evening. record the local air temperature at a sheltered outdoor thermometer as well. For those who have access to a computer data system, bury 2 temperature sensors 6 inches deep, and record the temperature hourly. I’ll bet a significant warmth of the nighttime insulated ground will accumulate.
I see someone has been posting here and at Tamino’s about the Stockwell and Cox paper (“submitted” last July to a forecasting journal); it’s at ArXiv. That ends up saying their statistic “predicts constant temperatures for fifty years to around 2050” (so starting at the turn of the century) but qualifies by saying their statistic “does not incorporate many of the complexities and natural forcing factors operating to produce climate change in the real world.”
Steve R @276: I’ve begun a blog dedicated to the debates I’m having with denialists. Every morning I search google news for climate and then get to it.
I’m not a climate scientist; I’m an unemployed geologist with a lot of time on his hands, I’d appreciate anyone to stop by and give me info on things I seem to be missing.
John E. Pearsonsays
821: That they are on shaky ground is corroborated by the journal they chose to publish in: International Journal of Forecasting which is a social sciences journal. If I were going to publish a serious article on climate I’d submit it to a journal which specialized in climate science. That they didn’t sets off my alarm bells.
#761 BFJ
How do you figure there has been no warming in 20 years?
http://data.giss.nasa.gov/gistemp/
http://www.ossfoundation.us/projects/environment/global-warming/temperature
#778 Martin Vermeer
Excellent perspective!
Ray @784
So aerosols caused the cooling from 1944-1974. Fair enough.
But what caused the temperature to rise quickly (nearly 0.5C) from 1910-1940 when there was an increase in CO2 levels of only 10ppm in that period?
In the past 30 years we have seen a 50ppm rise in CO2 for about a 0.6C increase in temp.
The figures do not add up.
Your theory of catastrophic warming relies not on CO2 alone but the resultant positive feedbacks from water vapour, the largest GHG. Water vapour can of course have a negative feedback through greater cloud cover and precipitation. No one really knows what is happening.
If you want people to believe you, you must provide the proof, not us who question the ‘evidence’.
[Response: Perhaps you could point me to the section in the IPCC report where it says that CO2 is the only forcing and that there is no unforced variability in temperatures? While we’re waiting, I’d like to point out that it isn’t scientists’ jobs to prove to you strawman statements that they’ve never made. – gavin]
#785 fabio
https://www.realclimate.org/index.php/archives/2009/12/unforced-variations/comment-page-16/#comment-151380
Facts out of context. Gee, that was easy. Essentially, the gist of the page is a pile of red herrings. Add rye bread and some cheese and you’ve got some snacks but no relevant perspectives on the science in accord with the ridiculous arguments as presented.
Think of it this way: Humans did not exist while dinosaurs walked around on the planet.
Also, our modern civilization and infrastructure has been built in accord with a particular climate, around thermal equilibrium, in the most recent 10,000 years.
Now we have added a significant amount of forcing.
http://www.ossfoundation.us/projects/environment/global-warming/forcing-levels
That means moving and changing infrastructure. How rich are you?
#793 Brian Brademeyer
“So reduced cooling clearly doesn’t equate to warming! Nominated for 2009 Howler of the Year!”
That’s right Brian, reduced cooling (like in a Thermos Flask perhaps) doesn’t equate to warming. Did you think it did?
Perhaps I should nominate “So reduced cooling clearly doesn’t equate to warming! Nominated for 2009 Howler of the Year!” for “2009 Howler of the Year!”?
[Response: No. Everyone is discussing temperature anomalies. Warming or cooling relative to some other situation. Using a blanket keeps you wamer than you otherwise would be, GHG, nighttime clouds – or high clouds at any time – keep the planet warmer than it otherwise might be. Please try and go back to arguing about something vaguely interesting. – gavin]
#795 Timothy Chase: “But the hypothetical snowball earth would have been much earlier than the Cretaceous — which was 206-144 million years ago.”
I’m sure that you meant 145-65MYA for the Cretaceous. Didn’t really want to nitpick here — just wanted to deny Dowden the opportunity to jump all over a “thinko” in an attempt to discredit your reply.
796, Ray Ladbury
From the second of your two links: ver a twenty year period, you would be on stronger ground in arguing that a negative trend would be outside the 95% confidence limits of the expected trend (the one model run in the above ensemble suggests that would only happen ~2% of the time).
And after 10 more years of the non-warming, we shall have a better appreciation of which of the models might be correct, and whether they are all wrong in important ways. According to AGW, what is the explanation for the lack of warming of the last 10 years or so, random variation? Trenberth rather bemoaned the lack of an explanation. Does AGW predict that the resumption of the trends of 1855-1885 (appx), 1915-1935 (appx) and 1977-1997 (appx) will occur randomly?
775 Andrew Hobbs: Benzene is a far more potent cancer causer. Benzene is found in petroleum and coal. I bet on benzene as the cause of those cancers. Radiation doesn’t cause cancer efficiently. If you want a guinea pig to get cancer, you paint it with benzene, NOT irradiate it.
Background radiation
From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Background_radiation
Background radiation is the ionizing radiation from several natural radiation
sources: sources in the Earth and from those sources that are incorporated in our
food and water, which are incorporated in our body, and in building materials and
other products that incorporate those radioactive sources; radiation sources from
space (in the form of cosmic rays); and sources in the atmosphere which
primarily come from both the radon gas that is released from the earth’s surface
and subsequently decays to radioactive atoms that become attached to airborne
dust and particulates, and the production of radioactive atoms from the
bombardment of atoms in the upper atmosphere by high-energy cosmic rays.
Since 1945 it also comes from low levels of global radioactive contamination due
to nuclear testing.
Contents
1 Natural background radiation
1.1 Cosmic radiation
1.2 Terrestrial sources
1.3 Radon
2 Artificial “background” radiation
3 Artificial radiation sources
4 Other usage
5 References
Natural background radiation
Natural background radiation comes from three primary sources: cosmic
radiation, terrestrial sources, and radon. The worldwide average background dose
for a human being is about 2.4 mSv per year [1] (pdf). This exposure is mostly
from cosmic radiation and natural isotopes in the Earth.
Cosmic radiation
The Earth, and all living things on it, are constantly bombarded by radiation from
outside our solar system of positively charged ions from protons to iron nuclei.
This radiation interacts in the atmosphere to create secondary radiation that rains
down, including X-rays, muons, protons, alpha particles, pions, electrons, and
neutrons. The dose from cosmic radiation is largely from muons, neutrons, and
electrons.
The dose rate from cosmic radiation varies in different parts of the world based
largely on the geomagnetic field and altitude.
Terrestrial sources
Radioactive material is found throughout nature. It occurs naturally in the soil,
rocks, water, air, and vegetation. The major radionuclides of concern for
terrestrial radiation are potassium, uranium and thorium. Each of these sources
has been decreasing in activity since the birth of the Earth so that our present
dose from potassium-40 is about 1⁄2 what it would have been at the dawn of life
on Earth. Some of the elements that make up the human body have radioactive
isotopes, such as potassium-40, so there is also a very small amount of internal
radiation.
Radon
Radon gas seeps out of uranium-containing soils found across most of the world
and may concentrate in well-sealed homes. It is often the single largest
contributor to an individual’s background radiation dose and is certainly the most
variable in the United States. Many areas of the world, including Cornwall and
Aberdeenshire in the United Kingdom have high enough natural radiation levels
that nuclear licensed sites cannot be built there—the sites would already exceed
legal radiation limits before they opened, and the natural topsoil and rock would
all have to be disposed of as low-level nuclear waste.
Artificial “background” radiation
Every above-ground nuclear detonation scatters a certain amount of radioactive contamination. Some of this contamination is local, rendering the immediate surroundings highly radioactive, while some of it is carried longer distances as nuclear fallout; some of this material is dispersed worldwide. Nuclear reactors may also release a certain amount of radioactive contamination. Under normal circumstances, a modern nuclear reactor releases minuscule amounts of radioactive contamination. However, reprocessing plants released waste, including plutonium, directly into the ocean. Major accidents, which have fortunately been relatively rare, have also released some radioactive contamination into the environment; this is the case, for example, with the Windscale fire (Sellafield accident) and the Chernobyl accident.
The amount of radioactive contamination released by human activity is rather small, in global terms, but the radiation background is also rather low. Some sources claim that the Earth’s background radiation level has tripled since the beginning of the twentieth century. In fact, the total amount of radioactivity released by man is inconsequential to the large quantities of radioactivity in the natural environment [2] (pdf).
Artificial radiation sources
The radiation from natural and artificial radiation sources are identical in their nature and their effects. These materials are distributed in the environment, and in our bodies, according to the chemical properties of the elements. The Nuclear Regulatory Commission, the Environmental Protection Agency, and other U.S. and international agencies, require that licensees limit radiation exposure to individual members of the public to 100 mrem (1 mSv) per year, and limit occupational radiation exposure to adults working with radioactive material to 5 rem (50 mSv) per year, and 10 rem (100 mSv) in 5 years.
The exposure for an average person is about 360 millirems/year, 80 percent of which comes from natural sources of radiation. The remaining 20 percent results from exposure to artificial radiation sources, such as medical X-rays and a small fraction from nuclear weapons tests.
Other usage
In other contexts, background radiation may simply be any radiation that is pervasive. A particular example of this is the cosmic microwave background radiation, a nearly uniform glow that fills the sky in the microwave part of the spectrum; stars, galaxies and other objects of interest in radio astronomy stand out against this background.
In a laboratory, background radiation refers to the measured value from any sources that affect an instrument when a radiation source sample is not being measured. This background rate, which must be established as a stable value by multiple measurements, usually before and after sample measurement, is subtracted from the rate measured when the sample is being measured.
Background radiation for occupational doses measured for workers is all radiation dose that is not measured by radiation dose measurement instruments in potential occupational exposure conditions. This includes both “natural background radiation” and any medical radiation doses. This value is not typically measured or known from surveys, such that variations in the total dose to individual workers is not known. This can be a significant confounding factor in assessing radiation exposure effects in a population of workers who may have significantly different natural background and medical radiation doses. This is most significant when the occupational doses are very low.
Reference:
http://www.unscear.org/unscear/en/publications/2000_1.html
[United Nations] UNSCEAR 2000 REPORT Vol. I
SOURCES AND EFFECTS OF IONIZING RADIATION
United Nations Scientific Committee on the Effects of Atomic Radiation
UNSCEAR 2000 Report to the General Assembly,with scientific annexes
Volume I: SOURCES
CONTENTS:
Report to the General Assembly
(without scientific annexes;17 pages)
Includes short overviews of the materials and conclusions contained in the scientific annexes
Scientific Annexes:
* Annex A: Dose assessment methodologies (63 pages)
* Annex B: Exposures from natural radiation sources (74 pages)
* Annex C: Exposures from man-made sources of radiation (134 pages)
* Annex D: Medical radiation exposures (203 pages)
* Annex E: Occupational radiation exposures (158 pages)
How do you know those cancers were caused by Chernobyl?
Gavin and all,
I had stated yesterday regarding your imminent 10,000,000 visitors since 2004 in comment 711:
I stayed up until 3:00 AM PST, and at that point you were shy of 10,000,000 by roughly 1,500 unique hits, so it would appear you did not make it in time for Christmas in any time zone. However, only a couple of months ago you were at less than 9,000,000 hits since December 2004, so it would appear that Real Climate is being looked to more than ever before for an understanding of what confronts humanity. And I would suggest that 10,000,000 will mark a very auspicious beginning to 2010!
@756
Oh great. A lecture on tone from the guy who arrived announcing himself as a “full blown scoffer,” boasted about his credentials outside of climate science, and blithely dismissed AGW with a wave of his finger, a little bit of jargon and some tired accusations about dogma, kool-aid, and denigrating the opposition — all with absolutely no sense of irony.
Like we’ve never seen that before.
Holy moly.
796, Ray Ladbury
tamino did it one way. If you do a statistical analysis that allows for “change points” or “switching regressions”, as documented in the econometrics literature and statistics literature (theoretical analyses) and recently published in the peer-reviewed literature (for temperature), there is a statistically significant change somewhere in 1998-2000. Tamino used a statistical technique with very low power to detect a change, should such a change exist.
Since tamino is a casual link, here is a casual link to the switching regressions report:
a prediction of cold climate.
captdallas2 — What about “climate shock” do you need tht cannot be found in “The Discovery of Global Warming” by Spencer Weart, first under Science Links on the sidebar?
#792 Ray
“If the system is warming, it can mean that Energy_in is increasing or that Energy_out is decreasing”.
Ray, I have a problem with that.
If for example Energy_in is zero and Energy_out is decreasing the system cannot be warming. It’s just cooling more slowly. You need Energy_in to be greater than Energy_out for warming to happen.
Or maybe I’m using words wrongly.
If you can sort me out on that I’ll be ready for the rest of your explanation to my #777.
Last 10 years: warming.
Last 10.5 years: warming.
Last 9.5 years: warming.
Walter Manny, OK, I’m a little confused here as to what your proposal is. We have a threat here, the effects of which could be disastrous. You admit that the consensus theory of Earth’s climate is the best model (in fact the only model) we have today. The theory–and it is an extremely successful theory–says that if we keep going down the path we are on, we could face very severe consequences, but that if we limit our CO2 emissions, we ought to be able to avoid the worst of those consequences. So what should we do? Should we follow the counsel of what the best scientific model of the climate model tells us, or should we do the exact opposite? Those are the choices, right?
Now, you say we might have a better model in the future. OK, but how do we make policy based on a model we don’t have now? In particular, even if we were going to get a better model, how likely do you think it is that it would dismiss CO2 to the level of unimportant player in Earth’s climate? Yes, Trenbreth and others express frustration at our inability to model short-term influences. That’s his job–to motivate people to come up with better models. We’ve had posts on that here at RC? That doesn’t invalidate the role of CO2, which is a long-term influence. Do you think that David Hilbert was indicting all of mathematics when he proposed his list of unsolved problems at the beginning of the last century.
As to sensitivity, I find it rather remarkable that 10 independent lines of evidence all favor a sensitivity of 3 degrees per doubling:
http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf
and preclude a level below 2 degrees per doubling.
And thirty years is not really arbitrary:
http://tamino.wordpress.com/2009/12/15/how-long/
And what pause:
http://tamino.wordpress.com/2009/12/07/riddle-me-this/
It looks like a pretty consistent trend to me. In any case, if 2010 were a big El Nino year and suddenly we had another record, would all your doubts about AGW vanish?
We can either go with the counsel of science or we can go against it. Science or anti-science. There’s no middle ground.
#805 Gavin’s response
“Using a blanket keeps you warmer than you otherwise would be, GHG, nighttime clouds – or high clouds at any time – keep the planet warmer than it otherwise might be. Please try and go back to arguing about something vaguely interesting. – gavin”
The sun is the only significant agency that heats the Earth. If things changed and one side of the Earth remained perpetually in darkness, that side’s temperature would fall inexorably towards zero K, more slowly in the presence of GHGs of course, but down nonetheless. If you (and climate science generally) call this a warming effect it may explain why I sometimes find you hard to understand.
Ian George, the warming from 1910-1944 is not as well understood as we would like. However, there were several known factors at play:
1)Increased insolation
2)decreased volcanic activity
3)increased greenhouse heating
Remember that warming due to ghg had been masked in the period from 1944-1974. Once clean air legislation removed the aerosols, the atmosphere warmed rapidly. CO2 is a continual forcing. It is not that temperature is proportional to CO2, but rather that increasing CO2 takes a bigger bite out of the outgoing IR flux, and the globe must warm up more and emit more IR as a consequence to reach equilibrium again. We’ve got the evidence. It’s up to you to learn the science so the evidence will make sense.
caerbannog wrote in 806:
You give me a little to much credit: I am a philosophy major turned computer programmer, not a paleoclimatologist, and as such I really don’t have the time frames memorized.
caerbannog continued in 806:
You are right, and your correction is most appreciated.
I was giving the time period for the Jurassic. Cretaceous was 144 to 65 mya, continent configuration would have been decidedly different.
However, according to:
Royer DL. 2006. CO2-forced climate thresholds during the Phanerozoic. Geochimica et Cosmochimica Acta, 70: 5665-5675
… referenced in:
Skeptical Science: CO2 has been higher in the past
http://www.skepticalscience.com/co2-higher-in-past.htm
… the last time we would have been as high as 2000 ppmv of CO2 would have been 200 million years ago, which coincidentally would have been very early Jurassic. The configuration of the continents would have been decidedly different, and likewise the climate sensitivity.
As such it really doesn’t affect the argument, likewise, just as you thought. But it would seem to suggest that both Blair and I have some additional studying to do.
OK, Simon, work with me here. Try to concentrate. I started with considering a system at equilibrium–Energy_in=Energy_out. In such a system if Energy_in=0, then Energy_out must equal zero, no. So Energy_out cannot decrease below zero, right? In fact, it can’t even equal zero in a real system.
And wrt your comment to Gavin about a planet where it’s nighttime 100% of the time, I’m sorry, but we were under the impression that we were talking about Earth rather than your planet. Also, as long as there is a fluid atmosphere, it will carry heat around to the other side, and eventually, you will have so much water ice, frozen CO2, etc. that your planet will tilt it’s axis in any case.
simon abingdon says: 26 December 2009 at 3:47 PM
“The sun is the only significant agency that heats the Earth. If things changed and one side of the Earth remained perpetually in darkness, that side’s temperature would fall inexorably towards zero K, more slowly in the presence of GHGs of course, but down nonetheless.”
Yeah, well that’s not reflective of actual conditions here, hmmm? I was totally confused about the point you’re trying to make, until I scanned back a few posts and realized that you don’t seem to know how a signal can be affected by noise. The signal of interest here is AGW forcing, the uninteresting signal is unforced variation. If you don’t know what those mean, why are you wasting your glucose with thought experiments about a tidally locked Earth when you’ve got such fundamental homework to do?
Matthew,
If you take a sufficiently complicated model, you can fit any data. That is why Occam’s razor is so important–or equivalently, you could use AIC. There is absolutely no physical reason given for assuming shifts in the data. Moreover, since they are modeling data with a pretty strong auto-correlation, I’d say they are on extremely shaky ground assuming such a complicated statistical model. Sorry, I’ll stick to physics rather than mere curve-fitting.
Re #795: Timothy, sorry if there was some confusion between the two separate examples of the Cretaceous and Snowball Earth eras. And contrary to certain paranoia here, I am not going to jump on minor errors.
Lets stick to snowball earth. Since we are talking in very round numbers, I don’t have much trouble with your analysis. I get four doublings of CO2 from pre-industrial levels to get to 16 W/M2, but a doubling of CO2 is a bit less than a 2% change in the solar constant. So Hansen’s proposed forcing to get a runaway greenhouse is something like a factor of three short of what occurred after the snowball earth episodes. This does not really support his argument, although it is not as bad as I first thought.
I do take issue with the climate sensitivity arguments. The high CO2 levels are reached before the ice starts melting. With the ice gone you are going to get a lot of evaporation and a large water vapor feedback (a fast effect), as well as increased absorption by the ocean and land weathering (slower effects).
I am not suggesting it is a good idea to force the climate to Cretaceous levels. This might be a little disruptive to our agriculture, not to mention 70 m of sea level rise. There are many good reasons to prevent greenhouse gas levels from getting anywhere near this level. I object to suddenly declaring a runaway greenhouse effect, which seems to be based only on a model that was not designed for those conditions, and some hand waving. A scientist should not be making scientific statements that are not backed by proper research and peer review. I consider this to be irresponsible and unnecessary; it discredits the reputation of climate scientists in general.
Finally, to undermine my own analysis, I do not understand why the snowball earth hypothesis relies only on carbon dioxide from volcanoes to reverse the process. Surely the same volcanoes would deposit ash on the snow, and in a world with no evaporation, thus no weather, the albedo would continue to decrease and cause melting before CO2 got to such extreme levels. If the hypothesis takes this into account, I have not heard it mentioned.
So go over there and confront him on his own turf.
Don’t let the fact that he’s a professional statistician who analyzes time series for a living keep you from proving him wrong …
PS to 818:
One more correction. Looking at Royer (2006):
… with the beginning of Phanerozoic ~575 mya having a solar luminosity of 94.5% what we have today and assuming that solar luminosity has change more or less as a linear function of time, 200 mya would have seen a solar luminosity ~1.9% lower than it is today.
Oh, Matthew, Matthew, Matthew, the site you link starts off saying …
Which is an outright lie.
You really expect any of us to read further after encountering that?
#818 Timothy Chase and caerbannog
deep time (geologic time)
http://en.wikipedia.org/wiki/Geologic_time_scale
to Sean @ #508, who asked about details of the peer review process…
the process is slightly different from journal to journal (and, I expect, from
field to field too). as John E. Pearson said earlier, the journal editor(s) will typically attempt to recruit reviewers who are familiar with the subject matter discussed in a newly submitted paper. most journals in the atmospheric sciences ask authors to recommend 3 or 4 potential reviewers (though I have no clue how often the editors actually act on these recommendations). when an invitation to review is sent out, prospective candidates are asked to decline if they believe they cannot provide an objective review.
the degree of effort put into a review can vary widely, and in general a reviewer’s comments are not available outside the journal’s editorial staff. one exception to this is Atmospheric Chemistry and Physics, which is a highly regarded “open access” journal that publishes submitted papers and reviews on-line. a complete description of the ACP’s Review Process, including manuscript evaluation criteria and the obligations for reviewers, is available at their website. the reviews themselves are posted online, so that you (and anybody else too) can download and read as many as you want simply surfing over to the ACP’s papers in open discussion section. in my experience, the quality and thoroughness of the reviews posted at ACP are representative of the reviews given for other atmospheric sciences journals.
817, Ray Ladbury: Ian George, the warming from 1910-1944 is not as well understood as we would like. However, there were several known factors at play:
1)Increased insolation
2)decreased volcanic activity
3)increased greenhouse heating
Isn’t the same true of the warming from 1855-1885, and the cooling that is identified as the Little Ice Age, and the warming that is identified as the Medieval Warm Period? That is to say, many known and hypothesized causes (Maunder Minimum for the LIA, to name just one), without a thorough understanding of the strengths of all?
Here is my answer to a question that is sometimes posed: In order for me to stop being a skeptic, I would need to see some more decades of warming like 1977-1997; in the mean time, we should have some prudent preparations, but not try to re-organize the energy economies of the developed nations and BRIC nations. In the US, replace coal with natural gas, for example, and continue to develop biofuels (including algal based) and carbon sequestration and storage. It would be a shame if the world invested in reduced warming and then experienced another little ice age because of the sun’s apparent reduced activity lasting decades. The solar theories are not “better than” AGW, they have problems of their own.
Walter Manny @769 said,
Or you could say…
It isn’t a conspiracy. The links between global warming denial and industry are well documented just as they were for the tobacco and cancer denialism.
Funding was given to think-tanks and politicians with the express purpose of making the public think there was some debate among those researching climate change (and among those researching tobacco and cancer). You and your friends may not be funded by oil, but pretty much every misconception you have can be traced back to think-tank distortions and lies.
Some of the same people and think-tanks promoting confusion and denial about global warming were involved in promoting confusion and denial about smoking, as well as about asbestos, CFCs, and acid rain. Same playbook, same tactics, different cause.
See Naomi Oreskes presentation American Denial of Global Warming
youtube.com/watch?v=2T4UF_Rmlio
and browse the database and articles at the desmogblog.com, and follow their links to original sources like Exxon’s own budgets, memos, etc.
Ray Ladbury wrote in 815:
Previously, Walter Manny had written in 769:
“Chronocentric” minds?
It would appear that Walter Manny has been dipping into Kant’s transcendental idealism again! (please see: Section 15: The Two Selves, Something Revolutionary) which I would argue is either self-referentially incoherent (Section 24, ibid.) or engages in widespread circular reasoning (please see: Section 29: Transcendental Idealism’s Primary Line of Defense, ibid.).
Personally I would much rather go with Ray Ladbury, the scientific consensus, and the best that empirical science currently has to offer — even if Walter and Kant would regard this as a subjective preference on my part.
How can I respond to the people who criticize AGW on the grounds that data and software code are not public? I am aware that some data is proprietary, but is code withheld? If so, what is the reason for that?
For any kids wondering who’s confused, this is what Simon’s denying:
http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
816 Simon A wrote The sun is the only significant agency that heats the Earth. If things changed and one side of the Earth remained perpetually in darkness, that side’s temperature would fall inexorably towards zero K, more slowly in the presence of GHGs of course, but down nonetheless. If you (and climate science generally) call this a warming effect it may explain why I sometimes find you hard to understand.
————-
Is this just a matter of semantics for you? If clouds in the night keep heat from being lost, then the next day, the heating starts from a slightly higher point, hence the nightime clouds help the OVERALL warming, although should they stick around during the next day, they would cause RELATIVE cooling, even as the temperatures rose.
I think that your issue is the insistence that a lack of cooling cannot be considered the same as warming, but can you see that the overall effect is warming?
Testing AGW.
Ray Ladbury : If we were to observe no warming for 20 years, it would certainly indicate that our theory was missing something. It would not, however, negate the known greenhouse properties of CO2 as a well mixed, long-lived greenhouse gas.
Sure; but OK, I get that you are also prepared to look at evidence. The question, it seems to me, is not so much just what CO2 is doing, but figuring what out the other (unknown?) factors are doing – the ones that presumably overwhelmed the presumed CO2 effect to give us a net result of no warming for the last eight or so years. What are these factors, and why did they change in about 2002?
I do think Cap & Dividend would make a great topic. Would need to get an economist or two involved for the item. Justification is that science directly relates to policy consideration. In fact that is largely why governments fund science, for the public good.
My Dec. Leading Edge Report was dedicated to this issue.
http://ossfoundation.us/projects/environment/global-warming/summary-docs/leading-edge/2009-dec-the-leading-edge
We pretty much knew they would produce a non binding agreement at COP15 months ago. That might prove to have been a good thing. It gives us a little time to education on ‘cap and trade’ v. ‘cap and dividend’.
In other words an RC article on Science and potential implications for economy in relation to policy choices. I know it’s complex but I think this is a good idea. Anyone else?
Matthew @828, of course the data we have become more sparse and less reliable the further we go back in time. Prior to the invention of the telegraph, it would have certainly been conceivable to have a large volcanic eruption in a sparsely inhabited part of the world without knowing it. ENSO is a relatively new discovery. The world prior to 1957 is vastly different in terms of how well we could observe it compared to the present. So the fact that there are a few epochs we cannot entirely understand does not detract from the successes of the current model.
And the problem is that we may not have another two decades to waste reverifying known physics. If we trigger large natural sources of CO2 and CH4, we won’t have the option of reducing greenhouse emissions via our own activity.
And your assumption that we can continue business as usual for a couple of more decades is simply not tenable. We don’t have enough natural gas to fuel growth in the BRIC countries, let along to fuel development if the rest of the third world reaches economic takeoff (as we hope they will). The global energy economy is simply not sustainable, even of anthropogenic CO2 were not an issue.
Matt, climate science has already been subjected to unprecedented scrutiny. Not only have the basic tenets of the theory passed 50 years of peer review and exhibited tremendous explanatory and predictive skill, it has also survived exceptional external scrutiny. National Academy panels, professional organizations of scientists in related fields, congressional committees, DOD, DOT, Foreign government agencies… Panels with impeccable credentials and integrity have looked at the evidence and the science and not one has dissented from the consensus science. Not one! Even the theory of evolution has never been subjected to this level of scrutiny! Sorry, Matthew, we can’t wait just because YOU don’t understand the evidence or science yet.
#819 Ray
OK Ray, I’m trying really hard.
You said (#792) “Constant temperature is a sign of a system at equilibrium–that is Energy_in=Energy_out. If the system is warming, it can mean that Energy_in is increasing or that Energy_out is decreasing”
Although you started with constant temperature you then said “if the system is warming…” (That’s not constant temperature any more is it Ray?) “…it can mean that Energy_in is increasing or that Energy_out is decreasing”. And I said (#813) “If Energy_in is zero and Energy_out is decreasing the system cannot be warming. It’s just cooling more slowly. You need Energy_in to be greater than Energy_out for warming to happen”.
Ray, does Warming mean Increasing Temperature, or not? Because it does in the world of ordinary people.
(BTW my Oxford graduate scientist daughter has just confirmed that warming requires the input of some sort of energy. Naturally I’m inclined to believe her).
And you said
Continuing my post #783 (re. effects of clouds):
simon abingdon@#791 had a question regarding the role of high thin clouds being net positive radiative forcings. The simple reason is this: they are largely transparent to most of the Sun’s spectrum (and so letting in much of the energy from the Sun), but are still black to much of the IR emitted by Earth’s surface.
I was just referring to someone to an old post ( https://www.realclimate.org/index.php/archives/2007/04/learning-from-a-simple-model/ ) and noticed that latex seems to have disappeared, rendering the math notation difficult to read. The archived posts are really useful resources, it would be great if you could manage to get the notation working again.
#820 Doug Bostrom
“why are you wasting your glucose … when you’ve got such fundamental homework to do?”
I’m trying to do it. At the moment I’m struggling with the bizarre notion that in climate-science-speak “warming” doesn’t only mean “increasing in temperature” but can also mean “cooling (decreasing in temperature) but not so rapidly as otherwise expected”. I find this usage altogether confusing.
Ray, I’m sorry but I reject your premise: “The theory – and it is an extremely successful theory – says that if we keep going down the path we are on, we could face very severe consequences, but that if we limit our CO2 emissions, we ought to be able to avoid the worst of those consequences.”
What is successful in the extreme about this theory? If it were so extremely successful, the smart folks you mention (the ones who are wrong) would not object to it, or they would not, in fact, be as smart as you say. I mean, hell, if my theory predicts temperature rise, I have a one in three chance of being right. You make it sound as though CO2 and global temperature were walking hand in hand down some Yellow Brick Graph.
What is extreme, however, is the extent to which you would need to change the world to limit the CO2 to the degree purportedly necessary to avoid the “very severe consequences” you fear. Surely that ship has sailed? Do you still believe that pounding the CO2 drum will ever bring down the rate of its growth, let alone reverse it? I suppose it could, but these Copenhagens are getting increasingly embarrassing.
Incidentally, I’m not referring to Trenberth’s frustration with short-term models. I’m referring to his frustration with short-term [and long-term] observations. “We’ve always had some problems with the observing system.”
Blair Dowden wrote in 822:
Perhaps when caerbannog suggested you might he was reacting to your use of the term “alarmism” which with me resulted in the association with “alarmists.” Those who use that term are usually the sort that would jump on minor erros.
Blair Dowden wrote in 822:
Water evaporation would have been a fast feedback — but the solar constant would have been closer to 98% of what it is now, not 99%, much of the heat would have gone into the melting of the ice, not evaporation at least for a while (although there would have been increasing sublimation — doubling for each additional 10°C above -40°C), and as I pointed out, much of the carbon dioxide would have been taken up by an ocean where the difference in partial pressure between the ocean and the atmosphere would have presumably been much greater than it is today. Furthermore, the partial pressure of water vapor wouldn’t have increased dramatically above today’s levels in reaction to higher temperatures until most of the ice had melted — and by that time the climate sensitivity that we would be dealing with would be much lower — since most of the ice had melted, exposing dark ocean and rock. The main feedback which would have been an issue during the early part of the transition from icehouse to hothouse would have been due to the albedo effect, not water vapor.
Furthermore, currently only about half of the carbon dioxide that we emit is left in the atmosphere after the first year that it is emitted. However, this is because much of that carbon dioxide is absorbed by the ocean — which wouldn’t come into play until the ice covering the ocean began to thaw to reveal the water beneath it. Furthermore, currently, if we were to stop adding carbon dioxide to the atmosphere, assuming a large slug (4,000-5,000 Gton), one third of what is left of the carbon dioxide added to the atmosphere would be taken up by the ocean within the first one thousand years.
Please see:
pg. 287, David Archer (4 June 2008) The millennial atmospheric lifetime of anthropogenic CO2, Climatic Change, 90:283–297
http://geosci.uchicago.edu/~archer/reprints/archer.2008.tail_implications.pdf
Now admittedly the slug we are talking about in the case of snowball earth is much greater, but then again, in the case of the 5,000 Gton slug added to today’s earth we are talking about an ocean that started out at equilibrium with the atmosphere, not one in which the ocean was heavily depleted of carbon dioxide.
In either case, a strict snowball earth is itself somewhat controversial. There are suggestions that a slushball earth is much more realistic in which case such high levels of atmospheric carbon dioxide would not have been required to result in a transition to a hothouse.
Blair Dowden wrote in 822:
I honestly do not know. Something worth digging into.
Comment by simon abingdon — 26 December 2009 @ 3:31 PM:
You said– “If for example Energy in is zero and Energy out is decreasing the system cannot be warming. It’s just cooling more slowly.”
You have also suggested similar reasoning in subsequent posts, but on a cloudy day the atmosphere still warms, just not as much as on a clear day. There is not zero input through clouds, and the clouds keep more heat in both during the daytime and nighttime. A simple example is an arbitrary clear sky day in the desert that is 90 degrees in the daytime and 40 at night, averaging 65. Compare this to a very cloudy day in northeastern Ohio that is a cooler 80 degrees during the day but only decreasing to 50 at night, so the average would also be 65 degrees. The point is that clouds damp the large day/night swings in temperature, and the question is– what is the net influence. Research suggests that it is slightly positive.
This is a simple concept and I don’t see why you don’t get it. In fact I believe that you do and your continuing obfuscation is deliberate. Perhaps this is your hobby.
Steve
Comment by Matthew — 26 December 2009 @ 3:24 PM:
The Stockwell and Cox analysis might have been more convincing if they had also identified the rather obvious break and shift between about 1950 and 1975, for which there is a known cause. They should have first tested the technique by applying it, blind, to several randomly selected temperature series’ from the past in order to be convincing.
Steve
Matthew @#828 says:
“It would be a shame if the world invested in reduced warming and then experienced another little ice age because of the sun’s apparent reduced activity lasting decades.”
Well, if we were to begin entering a ~1 century phase of another “little ice age”, we’d already have quite a buffer built into the pipeline, and those who understand the role of CO2 as a radiative forcing agent would know what to do then, right? But more seriously,…
The earth’s climate is a huge non-linear system. If perturbed gently, it behaves quasi-linearly albeit with delays in equilibrating. These delays aren’t hard to deal with, as long as the disturbances are small. We can do so in principle by reducing the C02 and CH4 that we pump either directly or indirectly into the atmosphere. What we cannot deal with is moving the Earth’s climate far enough away from equilibrium that it enters the strongly non-linear regime, whereupon positive radiative forcings begin reinforcing each other, sources of C02 and CH4 are dumped into the atmosphere and sinks thereof become ineffective. This scenario has happened in Earth’s distant past, as paleoclimatologists and paleogeologists will tell you (and there weren’t 7 billion humans then). Not only are the relatively rapid accumulative effects far beyond our means of control, but their rapidity means that these will be gifts that will keep on giving (and growing) because the Earth takes too long to equilibrate.
As for betting on the uncertainties — what we know of Earth’s climate, what we have been and are doing to it, and some of the potential consequences is far greater than we know what the Sun is or might be doing over the same time scale. The 11-year sunspot cycle, with its variability and probable accompanying changes in total solar irradiance, is akin to short-term weather, as regards to the Sun. (I am an astronomer by profession.)
Simon Abingdon, and any one else who wants to do a simple science experiment.
go to your local House Of Fraser/WalMart/kitchen shop and get two meat thermometers. Get a 50 x 2400 x 1200mm/2″x4’x8’foam insulation board from Wickes/Home Depot/DIY homebuilders shop. Stick the two thermometers into some flat exposed ground 2m/6ft/2 paces apart. leave them exposed during 4 or more successive days of clear weather, but cover one of the thermometers at night with the foam insulation. Record the temperatures of both thermometers every morning and evening. record the local air temperature at a sheltered outdoor thermometer as well. For those who have access to a computer data system, bury 2 temperature sensors 6 inches deep, and record the temperature hourly. I’ll bet a significant warmth of the nighttime insulated ground will accumulate.
More before and after glacier shots.
http://nsidc.org/cgi-bin/glacier_photos/glacier_photo_search.pl?collection=repeat
info:
http://en.wikipedia.org/wiki/Retreat_of_glaciers_since_1850
video
http://www.unep.org/wed/2007/Downloads/Multimedia/WED2007_VNR_English.wmv
other graphics and images
http://tinyurl.com/yfx2fnz
http://www.glaciers.er.usgs.gov/html/add.html
I see someone has been posting here and at Tamino’s about the Stockwell and Cox paper (“submitted” last July to a forecasting journal); it’s at ArXiv. That ends up saying their statistic “predicts constant temperatures for fifty years to around 2050” (so starting at the turn of the century) but qualifies by saying their statistic “does not incorporate many of the complexities and natural forcing factors operating to produce climate change in the real world.”
Steve R @276: I’ve begun a blog dedicated to the debates I’m having with denialists. Every morning I search google news for climate and then get to it.
http://ownid.blogspot.com/
I’m not a climate scientist; I’m an unemployed geologist with a lot of time on his hands, I’d appreciate anyone to stop by and give me info on things I seem to be missing.
821: That they are on shaky ground is corroborated by the journal they chose to publish in: International Journal of Forecasting which is a social sciences journal. If I were going to publish a serious article on climate I’d submit it to a journal which specialized in climate science. That they didn’t sets off my alarm bells.