Yes, if the pressure drops far enough, the water will boil. Alternatively, unexpected things in the air may contaminate the water and alter its properties. That would be the point - in the real world, the uncontrollable factors can completely change the observed result. The laboratory can take measurements at any atmospheric pressure or concentration it cares.
More to the point, the adsorption properties of CO2 demonstrably, by laboratory experiment, do not depend on any of those things: it depends only on the atomic structure of CO2 itself.
And the essential uncertainty is what effect CO2 and other gases have on the planet's normal ecological processes. That is not an "essential" uncertainty as far as attributing global warming goes, since individual forcings are measurable directly. It's more of an uncertainty about predicting how the forcings are going to change in the future, and therefore for predicting future climate change.
We don't know what's going on there and we don't know why the CO2 levels are increasing instead of being maintained. That is complete BS. We have far better understanding of both the terrestrial and the ocean carbon cycle than that, more to the point, we know that the CO2 levels are increasing largely due to fossil fuels, because we can identify the fossil-fuel derived CO2 in the atmosphere: it has a different isotopic composition than CO2 from other sources.
It doesn't help that all the theories say that a warmer planet will generate higher CO2 levels. Correlation != causation: we don't know whether the CO2 is causing the temperature or whether the temperature is causing the CO2. That is a pure lie. It is an inescapable physical FACT that CO2 causes warming. It causes warming regardless of how the CO2 gets there, too.
We can demonstrate in the lab that both are possible, and that tells us nothing about which one is actually happening. Also dead wrong. We know that temperature increases can cause higher CO2 levels, e.g., by reducing the ability of the oceans to hold CO2. We also know that such CO2 will cause warming. And we also know that most of the CO2 increase over pre-industrial times originates from fossil fuel burning.
That is a bare-faced lie. The fact that the planet has warmed and that CO2 is somehow involved in that is now beyond reasonable doubt. That is total and utter denial of facts. It is established beyond all reasonable doubt that the planet has warmed, and that anthropogenic CO2 is a significant contributor.
The recent IPCC report is very clear on this: planet hotter, Yet you deny even that.
causes uncertain (human-related causes "likely" to be a significant factor, but that could be anything from 1/10 to 9/10 of the problem), They do not say that it is anything from "1/10 to 9/10" of the problem, and they say directly that "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations". (In their jargon, "very likely" means "probability >90%".)
solution impossible at current level of knowledge. The IPCC said no such thing. In fact, the SPM (the only document so far released) said nothing at all about solutions. The previous report did talk about solutions, and most certainly never said "a solution is impossible".
Nope. It is a forcing. Water vapor holds a higher concentration of the greenhouse effect then Co2 does and is more abundant in the air. And when the sun causes more water to evaporate, it causes more watervapor to be in the air wich causes more heat to be retained. In a models sence of wording, it would be the underlying force. And therby a forcing.
That's not what a forcing is. Water vapor causes warming, yes, but it is not a forcing, according to climatology jargon. I already gave you a link to an article explaining the difference in terminology (here)
I think it is clear you don't understand theworking here.
Don't lecture me on climatology. You've been making moronic statements about it which I have been patiently correcting for a month now.
The sun gets hotter. It evaporates more water and raises the air temperature. The increased humidity traps more water then something comes along and attached to it creating clouds. Now clouds block some of the light reducing the effects of the sun.
I know that. In fact, I explained it to you once. It still doesn't make water vapor a forcing.
No, the forcings due to contrails and such are largely independent of whatever the global warming is due to.
No, the paper like you, are trying to attribute the wrong information to the desired outcome.
No, it's basic physics. Contrails do not magically act differently if the temperature is being raised by CO2 or by something else. Contrails don't care what is causing the temperature increase.
How much stronger? The amount of heat caused by the increaded water vapor stronger?
The positive feedback from increased water vapor acts the same regardless of whether the water vapor increase is being produced by CO2-based heating or by Sun-based heating. Water vapor does not amplify solar heating more than it amplifies CO2 heating. It amplifies any heating in the same way. The forcing from solar variations is much smaller than the forcing from CO2. Water vapor amplifies both forcings, but the solar variation forcing remains much smaller because it started out much smaller.
It doesn't need to be that much stronger, the sun isn't the only factor in this.
Yes, it does need to be much stronger than it actually is.
The Co2 models discount a lot of these factors by negating watervapor effects in favor of making Co2 apear stronger.
Once again proving you don't know the first thing about climatology. Yet you presume to lecture others on it.
Climate models do not "negate" or "neglect" water vapor effects. All climate models include water vapor feedbacks. Those feedbacks act on ALL forcings in the system, not just CO2 or just anthropogenic forcings.
I'm saying let the science prove it out.
It has been. The fact that you refuse to accept it says more about your bias and ignorance than it does about the science.
There is and always has been a lot of support for the sun being the cause.
There isn't and there hasn't. The Sun has been ruled out as the major cause of global warming. Deal with it. It makes a contribution, but it's much smaller than anthropogenic factors.
With the sun, it will fic itself. With human caused GHGs we are fucked unless something drastic is done.
The Sun won't necessarily "fix itself" any more than GHGs will. Eventually the solar intensity will change, and eventually GHGs will get scrubbed from the atmosphere, but neither are necessarily going to happen on any time scale that's convenient for us.
(More accurately, the Sun gives a measurable but small contribution, and greenhouse gases give a measurable and large contribution.)
Besides humans who live on the coast I really don't think a 5-6C increase in temperature is going to effect anyone much. Global warming has effects beyond the direct temperature increase, including more extreme precipitation events (blizzards, floods, droughts), shifts in which regions are agriculturally fertile, stress on the water supply, new disease vectors, impacts on fisheries, and so on. More extreme high temperatures doesn't help either.
As for the people on the coast, sea levels are rising currently at about 2mm (yes millimeters) per year. That's less than an inch every 100 years. Sea levels will rise at an increasing rate in the future as global warming accelerates, given reasonable assumptions about emissions scenarios. The IPCC predicts up to 60 cm rise by the end of this century, and that's not counting unquantified dynamical ice instabilities — far more than "an inch".
In stating that we may not WANT a 5-6C increase in temperatures you are assuming that we can control 100% of the climate. No, I am not.
Again, if this increase in temperature is due to a natural process we really don't and shouldn't have any say in it. It is not due to a natural process, and even if it were, we can still have a say in it.
You are assuming that even though there have been ice ages and temperate periods in the past, now that we are here we need to "normalize" the climate and make sure it stays within some arbitrary bounds of normal defined mostly by a) when we first made thermometers and b) when we first measured CO2 levels. Yes, we do want to keep the climate within the bounds that we prefer it, regardless of what it has done in the past. Just because it's "natural" doesn't mean it's what we want to happen.
Try reading, say, anything from the entire climatological literature over the last 30 years. The fact that you choose to dismiss it does not make it any less credible.
Read the scientific literature. You can start by the references in the IPCC reports.
"we" didn't know enough just a few years ago, before knowledge of increased solar output caused scientists to adjust their numbers by up to 1/3rd,
Adjusting variance in solar output by 1/3 still does not come close to making solar variations a dominant effect.
again with global dimming, and again when the fact that plants and soil will emit some greenhouse gases when they are warmed.
Once again, none of those have come close to approaching anthropogenic CO2 in effect size. The fact that we have improved our estimates of natural forcings does not somehow mean that we suddenly don't know anything about their values or relative significance. It is not credible that there is some huge natural effect that we have simply overlooked. And even if there were some huge unknown warming effect, there would also have to be an even huger unknown cooling effect to cancel out the greenhouse effect, because you simply cannot escape the physical fact that anthropogenic CO2 produces substantial warming.
Somehow the climate models didn't pick-up that something was wrong with the numbers before those discoveries.
The adjustments are well within the error bars of the models, which is what matters. If the new values were outside the previous range of plausible uncertainty in the model estimates, then there would be a problem.
So I fail to believe there's been a world of improvement in just a few years.
Anthropogenic global warming was already established science "a few years ago" just as it is now; nothing has changed that.
I'd very much like to see a comprehensive summary of other possible causes, and any kinds of feedback loops on the planet, which may account for even more of the warming, and therefore adjusting the numbers for man-made warming even further.
Like I said, go read the scientific literature. It is vast. Are you under the impression that nobody has looked at other causes or feedbacks?
No, it isn't. What if most Earthquake "experts" predict California is going to fall off the face of the Earth, into the Pacific Ocean, within a year?
You can't support your point by making up an example of an obviously false scenario that "experts" all believe.
In the real world, most earthquake experts do not predict that, because it is extremely implausible.
How about if 9 out of 10 doctors believe you have a disease, for which there is no test, and where the knowledge of the disease is so poor that even the list of symptoms requires significant interpretation?
Again, fictional scenarios do not support your point. In the real world, 9 of 10 doctors will not tell you have a disease if they can't even test for it or know anything about it.
Perhaps we can restrict our discussion to real groups of experts, and not fictional groups of idiot strawmen.
No, it's irresponsible to defer all consideration to them,
Who would you prefer to defer consideration to?
particularly when it's understood that the science in the specific field is rather primitive,
It is not so primitive that it can't detect the huge effect of anthropogenic global warming.
they've made numerous mistakes in the recent past,
This is disingenuous. Any time science improves you can claim that the previous science was "mistaken" and therefore no science is trustworthy.
The fact is, estimates of the contributions of individual effects are continually improving, and the conclusions over the last 25 years regarding the significance of AGW have not changed; indeed, the evidence has continued to mount in its favor.
the scientific method doesn't apply well,
That is completely false.
and the current best-evidence has a huge margin of
Do 'resistance temperature detectors' not require digital electronics to record or even read the data? Were such things really around in, say, the 1920s? No. Thermometers in the 1920s did not have 0.05 degree accuracy. It was more like a few tenths of a degree, although I don't have the exact figures on hand. Even two hundred years ago they were as good as 0.5 degrees sometimes, at most 1 degree inaccuracy (in C).
The problem is this kind of stuff is never discussed by either side and it is important. Just because you don't read the scientific literature doesn't mean it's not discussed. You can't get an experimental paper published without discussion of the accuracy of the data you're using. You have to go back in the literature a ways to find that information, since people tend to just cite other people's errors bars once they've been published. Every once in a while, groups like the World Meteorological Organization will do recalibration studies to update the error estimates for the raw data.
It is certainly the case that the error bars get larger the farther back in time you go.
But have [urban heat island effects] been accounted for sufficiently? IOW, how accurately can we measure such effects? I don't remember the latest estimates, but I do remember that the effect is no greater than 0.05 degrees, and may in fact be zero. I would thus estimate the error bars to be no larger than ~0.025 degrees.
Extraordinary claims require extraordinary evidence. After more than 50 years of study, we have vast amounts of evidence. Today the extraordinary claim is that we are not affecting the climate, and requires analogously strong evidence.
The underlying principle is the models used to calculate the effects. If the sun isto blame, you take watervapor and change it from a feedback to a forcing. No. Water vapor is a feedback, regardless of whether the dominant forcing is CO2 or the Sun.
As a forcing instead of feedback it then becomes the most abundant and influential greenhouse gas. making the Co2, methane and all minute amounts and the human contributions to them even less significant. You can't suddenly make water vapor a major contributor merely by calling it a "forcing" instead of a "feedback". You get the same water vapor feedback no matter what the underlying temperature increase is due to. Water vapor does not become magically potent if something other than CO2 is driving the temperature increase.
But it in no way attempts to acount for the impact under a model different then Co2 emisions as the problem with Global warming. No, the forcings due to contrails and such are largely independent of whatever the global warming is due to.
But when you change the base for the studies as it would be neccesary when usig the sun as the major factor, it changes the way the studies look at things. You can't change the studies to make the Sun a "major factor" unless you make the Sun stronger than it actually is.
And yes, in science, just like math, You can have more then one way to get to the same answer. In this case global warming is the answer. Greenhouse gasses (more specificly human caused green house gasses) is one way to get to the answer while the sun is another. However, the Sun gives the wrong answer, and greenhouse gases give the right answer.
(More accurately, the Sun gives a measurable but small contribution, and greenhouse gases give a measurable and large contribution.)
The simple fact is that temperature measuring technology that is actually used to measure the air within a useable temperature range is highly imprecise and highly inaccurate.
Got any data to back that up? I want to see the manufacturer specs on the actual equipment that has been used at the hundreds of temperature measurings stations around the world for the past 100 years or even 30 years. Go ahead and try to find that data.
If you want to assert that the accuracy and bias of temperature measurements is something other than what studies have shown it to be, it is incumbent upon you to demonstrate that — and even moreso, that these errors introduce a systematic upward bias into global temperature averages of a magnitude sufficient to render the observed global warming an artifact of measurement error.
Thermometer intercomparison studies do exist; I saw one cited in a similar Slashdot thread last month, which I've spent the last 20 minutes trying to find. As I said, if you want to dig around on Web of Science or Google Scholar long enough, you can find them too.
Most will only be able to measure temperature to within +/- 2C!
That is completely absurd. Even thermometers hundreds of years ago could accurately measure temperatures to better than 1 degree accuracy. Meteorological thermomenters in the 20th century are far more accurate.
And note again that the combined average of many thermometers are more accurate than any single thermometer.
I would love to know where you are getting these "facts".
This theory is so far from it that hardly anyone even bothers to talk about the uncertainties in that data.
Idiot. Read any paper on the instrumental temperature record and you will find discussion of the uncertainties in the data. Track the references back far enough and you will eventually find the calibration and bias estimation procedures used.
We seem to be assuming no human error whatsoever in the the recording of the temperature readings.
No, we do not. Human errors, both random and systematic, can be and are estimated. Search the literature for "bias correction", "cross validation", etc.
Such questions should at least be occuring to you. The fact that they are not makes me wonder about whether you really care about the truth.
I have not claimed that the instrumental temperature record has zero error. I merely claimed that the errors in the record are much smaller than the warming trend observed. The fact that you know nothing about how that record is calibrated and debiased tells me you certainly do not care about the truth.
I would sneer at the idea that it would mean the end of our species and openly laugh when you claim to have evidence that would prove it without the slightest doubt.
No one has claimed that global warming will "end our species". But the existence of global warming has been proved beyond reasonable doubt.
I would quite like an extra 5-10F increase at the lattitude where I currently live.
I doubt that you would, as temperature increase is far from the only effect of global warming. And nice of you to care so much about people at other latitudes.
Just means that there would be some migration away from equatorial regions.
Oh, yeah, "some" migration. I'm sure you would like to support the costs of that relocation, too, along with the social and political unrest which accompanies it. (More likely, you would prefer your fellow taxpayers, or ideally other countries altogether, support it.) Not to mention your complete lack of ethics in supporting climate change which results in the relocation of other populations which conveniently don't include you.
Actually all of them are. hehe. Okay. Sorry about that. Couldn't resist.
Not all of the world's population centers are located close to sea level at the ocean front,
Temperatures where higher in the past WITHOUT human intervention. Again, duh.
Couldn't that also be the case this time. No. The present warming is at a far greater rate than past warming, and more to the point, we can measure the contributions of both natural and manmade effects today, and the latter far outweigh the former.
Sheesh. Quite being so purposely obtuse. You're the one being purposely obtuse. Your logic is horribly broken if you think "natural effects have produced warming in the past" means that "warming in the present is due to natural effects".
We don't need to know anything about the past climate to know that natural effects are not the dominant contributor to climate change today. But if you want to include historical data, that only strengthens the case that the current warming trend is not natural.
Ummm, from the historic temperatures which have always hit an upper limit of approximately the same value over and over again You will note that historically CO2 levels were nothing like what they are projected to become by the end of the last century.
Negative feedbacks do kick in eventually, so that temperatures will not grow without bound, but you cannot point to past trends without also pointing to the gross differences between the past and present climate.
Temperatures hit will hit a limit in the future as well, but the limiting temperature will be much larger when the climate comes into equilibrium with the much larger amount of CO2 that is now present.
If we are perturbing the system, there seems to be only one real direction it can go. This is manifestly false, as (a) the Vostok data gives no indication of what happens to interglacials when CO2 concentrations are above 300 ppm, and (b) temperatures in previous geological eras far exceeded any interglacial period visible in the Vostok data.
Nobody is claiming that global warming is going to wipe out our species. Nor do we need a "death penalty" on combustion, or revert to pre-industrial civilization. We can abate CO2 emissions by changing power sources, developing more efficient technologys, changing consumption patterns, and so on. We do not need to eliminate emissions entirely to have a positive benefit.
First, those "deniers" are only denying that man is the cause of global warming. There is a whole spectrum of denial. Some deny there is any warming. Some deny that we're causing most of it. Some deny the warming will continue. Some deny we can do anything about it. And so on.
I remember being told by fear-mongering scientists as a child that we would be out of coal and petroleum by 2010 and uranium by the mid-1990s. Really? Which "fear-mongering scientist" told you that? Did you read it in a journal article, or in the media? And were these scientists climatologists, or geologists?
Second, the data on Mars undermines the current scientific groupthink about man causing global warming on Earth as it is an independent data point. The only possible link in climate between Earth and Mars is solar output. Solar output is known to be too small to be responsible for the global warming here on Earth (see Foukal et. al in Nature last year), and it's also not responsible for Mars's warming (which is not even global), since solar output decreased during that period (see Steinn Siggurdson's guest post on RealClimate).
Since data suggests that Mars is experiencing similar warming (and other planets based on another poster's links), The other planets also have nothing to do with our climate (see here).
then it calls into doubt the groupthink that man is the cause. It's not "groupthink", it's a scientific conclusion arrived at from decades of research.
Furthermore, if you want to claim that man is not the cause of global warming, and try to introduce a previously-unknown new warming effect, you also have to introduce an even bigger previously-unknown cooling effect to explain why greenhouse gas emissions aren't warming the planet even more, on top of this new warming effect. It's not credible.
It suggests the Sun is a big contributer, which is an assertion made by those who deny-that-man-causes-global-warming. The fact is, the Sun is not a big contributor to global warming, and you don't need Mars to tell you that: we can measure solar output directly.
My own observation is that there is a logical fallacy. When deniers deny global warming, they refute man's role in global warming. I think both sides agree the warming is occurring---part of the natural cycle of the Earth's pattern. There was an ice age, after all. We've obviously warmed up quite a bit since then. I doubt cave men had a significant impact on climate then to be the culprit. But, I digress. Those who support the notion of man-made global warming respond by claiming that the denial extends to the existence of warming period.
Another interesting point is by calling them 'deniers,' there is an implication that they refuse to accept the truth. That's right. As much as you want to paint deniers as noble and daring persecuted revolutionaries, the fact is, the existence of anthropogenic global warming is by now well established, and their counterarguments are not credible.
First, new opinions are ALWAYS at odds with "mainstream scientific opinion." No, often new opinions end up supporting the mainstream. Perhaps you meant to say, tautologously, "contrary opinions".
In the old days, the "scientific old guard" used to have their opposition hung as heritics. Today, you are politically persecuted and discredited. You're being ridiculous. Contrary ideas appear in science all the time, get published, and become accepted. The secret: the scientists who propose them have to actually be able to support their claims with good evidence and arguments.
Abdussamatov is a crackpot, plain and simple. He has not offered bold new theories; he has not even related Mars's climate to Earth's in any causal way. He denies that the greenhouse effect even exists, which is manifestly incorrect.
The fact that this body is named the IPCC instead of the IPCS (Intergovernmental Panel on Climate STABILITY) indicates a distinct political bias. Afterall, we are looking to undestand how our climate maintains STABILITY, not to point fingers at bad guys who "corrupt the earth to satisfy their avarice," right? What the hell are you talking about?
Our climate is changing, and they are looking to understand why it is changing. Our climate has stabilizing factors, but it still is changing, which is the whole reason why it is important for the issue to be studied.
Finally, your reliance on CO2 as THE CAUSE ignores the fact that water vapor contributes much more significantly to greenhouse effects. Sigh. Not this nonsense again.
Water vapor contributes to most of the natural greenhouse effect on Earth. But that doesn't matter as far as global warming is concerned: global warming is the change in temperature since pre-industrial times. It correspondingly is attributed to the change in greenhouse gas concentrations since pre-industrial times. Most of the GHG increase is from manmade CO2, and so is most of the increase in temperature.
Whether or not the leading contributor to global climate change is cyclic (sun, earth, astrophysics, weather, etc.) or caused by new concentrations of elements in the atmosphere (CO2, H20, etc.) the leading SOURCE of energy is the sun. It is BAD SCIENCE to ignore potentially NEW information just because it disturbs your politically neat wold view... No one is ignoring the existence of the Sun. Sheesh. Insolation is well studied, and changes in insolation are known to be too small to account for the observed warming, which is another reason why Abdussamatov is a crackpot. He hasn't produced any new reasons to believe that insolation is larger than was previously thought, he merely tries to deny the existence of the greenhouse effect or even that humans are responsible for the observed CO2 increase.
Comtrails produced by aircraft are another source of cloud seeding. So ending comercial airservice to cut down on Co2 emisions could be counter productive if the sun is actualy the problem. The climatic effect of ending commercial air service was studied when said service was halted in the U.S. on 9/11. The net effect of aviation is still believed to produce overall warming; see, e.g., section 3.2 of this study (where they report a positive value for the overall radiative forcing due to aviation; positive values mean warming, negative means cooling).
I think that the question of whether there has in fact been any measurable increase in global temperature at all is still open for debate. No. It's not. Even skeptics like Lindzen acknowledge that now.
No one seems to want to discuss the actual mechanisms used for measuring said temperatures. Their reliability. Their accuracy. No one except for scientists, of course. Go to Web of Science or Google Scholar and search for papers on temperature calibration and bias. The issue certainly has been studied.
Go out and find me an accurate and precise general purpose thermometer. I dare you. Read the actual specifications and see the limits to temperature measuring technology that is actually used to measure air temperatures. Then come back and tell me how we can be so certain of increases of only a fraction of 1 degree celsius. Modern meteorological thermometers have an accuracy of 0.05 C or better. Averaging of many temperature measurements increases the precision of the averaged result.
And that is without even measuring whether urban heat island effects have been adequately taken into account at all times. Urban heat island effects have been studies extensively.
Was that station in Siberia really so accurate 30 years ago? How about 50 years ago? Was it properly calibrated at all times. Are you seriously proposing that all thermometers 50 years ago were miscalibrated in the same way? Global averages depend on more than just "that station in Siberia". Cross-validation is also performed between more accurate and less accurate stations.
Human arrogance certainly has not diminished in the past 50 years. Of that I am certain. Every 5 year old seems certain that they know everything there is to know about the world. So our confidence in our ability to make such grand predictions should not surprise me. I am sure you apply this skepticism to deny the validity of every other scientific result that has ever been published as well. "Oh, their instruments were just imprecise and miscalibrated, I'm sure the effect doesn't exist".
It was more than a single article, but it was still only a few articles. The most prominent was in Newsweek, and also one in Time.
In fact, despite the media scare in the 1970s, scientists were not predicting a coming ice age. The general idea was that natural effects were causing a cooling, but there wasn't enough information to tell whether manmade effects would offset that cooling (from the greenhouse effect), or contribute further to it (from aerosols and particular matter). After 10-15 years it became evident that they produce an overall warming. Also, much of the manmade cooling effect was removed with tighter pollution controls.
You can read more about the history of "global cooling" here, here, and here.
How many scientific studies have been reported on/. only to be dismissed by many people saying "correlation != causation"? Why does everyone forget that, when the subject is global warming, or some other issue they like? Slashdotters are often wrong to dismiss scientific studies; in general, the scientific knowledge of the average Slashdotter is much lower than Slashdotters commonly assume.
That being said, new studies by a single research group are always on shakier ground than the combined conclusions of an entire scientific community over decades of work.
Guess what, scientists make mistakes. They have made mistakes on global warming, and continue to make mistakes. Scientists never claim global warming is a fact, they only speak to their own observations. Your first two sentences are correct, but pretty much any climatologists will tell you that global warming is a fact, and rightly so. It is beyond credibility at this point to deny that the Earth has warmed over the last 150 years. It's also no longer tenable to support the claim that humans had little to do with it.
Personally the main issue I have with the whole global warming hypothesis is just that. Climate modelling is a joke. If by "a joke" you mean "hindcasting past climate with reasonable skill", then perhaps.
The fact is, climate modeling is not that bad if you don't push its predictions past a century or so. Climate models do fit the observations, and it's not just overfitting; you can't get the models to fit any set of observations. In particular, you can't get models with only natural or only anthropogenic forcings to fit the observations; you need both.
I also don't trust the accuracy of temperature measuring stations around the globe for the past 100 years. Now you're being ridiculous. Global warming is not even remotely an artifact of inaccurate temperature measurement.
With the small (barely detectable by the limits of thermometer accuracy and precision) tempurature increases the earth is not going to become like venus in 50 years time. The temperature increases that have been measured are much greater than the limits of thermometer precision. And nobody is claiming that "the Earth is going to become like Venus in 50 years time". That's a strawman constructed to make concerns about global warming look absurd.
Hell, it hasn't even been proven in any even remotely scientific way that increased average surface temperatures will have any significant negative effect on, well, anything. We know that plants would be happy. That's not wholly correct; it will, in general, encourage plant growth, but some species will suffer as the local climate changes alter their preferred climate, and crops can have decreased nutritional content even when their overall growth increases.
Although, no doubt equatorial folks would be a bit miffed at having to deal with days that are a few degrees warmer on average. 5-10 degrees F warmer is quite possible and is nothing to sneer at, even in non-equatorial regions.
And if sea levels really do rise the rich people who own ocean front homes will be a bit ticked off if they have several feet of seawater in their house. A great many of the world's population centers, and a number of entire nations, are close to sea level at the ocean front. It is not just "rich people's" problem. In fact, poor people will be disproportionately affected, as is usual.
You're also neglecting the damages and deaths from more extreme weather events, the consequences of droughts, disrupted ecosystems, fishing patterns, shifts in regional climate, new disease vectors, and so on.
I don't know what your point is. What is the "energy/heat cycle"? Are you claiming that nuclear power causes global warming? What negative effect is nuclear power supposed to have on the Earth.
Whether nuclear power ultimately derives from solar energy or not is largely irrelevant to any useful question about the utility of power sources.
The science is a bit sketchy, because we just don't understand climatology remotely well enough to give a conclusive answer. At this point, we do understand climatology well enough to know that CO2 and other anthropogenic effects are reponsible for most of the warming we've seen, particularly in the last 40 years.
There is rather less certainty regarding what the climate will do in the future, but we know enough to say that it will continue to warm at least to some extent.
Personally, I'm quite saddened that the supposedly smart people here on/. take such a hard line on the issue, mostly in favor of cutting emissions, despite the fact that the/. mantra that "correlation != causation" is being selectively ignored here. We have far more than correlational evidence for CO2-based global warming: we know a direct causal mechanism that links the two (the greenhouse effect), and the predictions of this theory match observations. Predictions of alternative theories (e.g., increased insolation) have not. That says a lot more than just "correlation".
And that facts aren't a matter of democracy, so "most scientists" isn't a good argument at all. The considered opinion of experts is always a good argument. Experts are not always right, but it is absurd to dismiss what experts think simply because they may be wrong.
Fresh water freezes at 0 C in the lab. Dropping the temperature to 0 C obviously can never cause water to free in the real world.
We are talking about the laws of physics here, you know. The electromagnetic adsorption spectrum of CO2 does not somehow change in the atmosphere from what it is in the lab.
I don't see how the earth can trap more energy then a black body and therefore it cannot have a higher temperature -- blackbody is the upper limit. You may not see it, but it is nevertheless true: if you construct an energy balance model, treating the Sun and Earth as blackbodies, you get the wrong temperature for the Earth. Oops, you forgot to take into account that the Earth isn't a perfect absorber. Put that albedo, and you still get the wrong temperature: it's too low by about 50 degrees. There is something producing excess warming over what a simple blackbody model predicts. It's not a perfect radiator, either: you need a greenhouse effect.
You can find calculations of how it contributes to temperature in climatology textbooks, or hunt around on the web (e.g. here).
In the link above (an applet) notice how it looks like there were higher temperatures in previous interglacials? Yes, the temperature has been higher in the past. What is your point?
I see a strong correlation with the CO2 that suddenly stops ( saturation?) Not saturation, just that the ice age cycles were being driven a lot by Earth's orbital variations as well as CO2. Above 280 ppm CO2 is the industrial period, where temperature is being driven mostly by CO2 alone.
Note that the industrial temperature/CO2 correlation is still there: the correlation does not disappear, it merely changes slope. In fact, the correlation between the two (measured by how well the data approximates a straight line) is much stronger than in the pre-industrial ice age cycles, meaning that the current temperatures are much more closely determined by CO2 levels than they have been in the past.
There seems to be a lower and upper bound. The earth seems to be bouncing between two states, kind of like a Lorenz butterfly. If anything I would be more worried about us perturbing the 'orbit' of the system in such a way to send us into an Ice Age. Given the apparent dynamics of the system (2 strange attractors?) that would seem a much more likely danger. Umm, out of which thin air did you pull this latter conclusion from?
Actually, we've gotten to the politicised stage where it's hard for papers with contrarian ideas to get past peer review. That's because there is less and less support for contrarian viewpoints nowadays, because there is more and more support for the now-accepted AGW viewpoint. "Contrarians" can still get published, but they have to make a much stronger case for their thesis than when there was much less known about the climate.
The only reason this study is such big news is that it's taken this long for a paper like this to get published. The only reason this study is news at all is because the media wants to play up the "both sides of the story", ignoring the fact that a climate connection between Earth and Mars is not credible. (The only possible link, increases in solar variation, has already been studied in detail and found to be lacking.)
Children in other counries attend cram (make-up classes) schools as standard practice (not extraordinary) They do that day-in day-out six days a week. Could we have become so weak and decrepit mentally that we cannot put up with some additional studying? Perhaps you should also ask what the educational and psychological benefits or drawbacks are for children in other countries who go to cram schools. You say that other children do it, so if we think it's a bad idea, we must be "weak and decrepit mentally". But you don't ask whether it's good for those other children.
This attitude is not the real world one encounters after high-school. The real world one encounters after high school doesn't usually have homework at all: the job ends at 5 PM. What's your point?
By the way,
(if [the greenhouse effect] didn't exist, how could we make greenhouses?) The "greenhouse effect" referred to in global warming is different from how actual greenhouses work. The former has to do with absorbing infrared radiation from the Earth; the latter has to do with preventing convective cooling.
Slashdot Mirror
More to the point, the adsorption properties of CO2 demonstrably, by laboratory experiment, do not depend on any of those things: it depends only on the atomic structure of CO2 itself. And the essential uncertainty is what effect CO2 and other gases have on the planet's normal ecological processes. That is not an "essential" uncertainty as far as attributing global warming goes, since individual forcings are measurable directly. It's more of an uncertainty about predicting how the forcings are going to change in the future, and therefore for predicting future climate change. We don't know what's going on there and we don't know why the CO2 levels are increasing instead of being maintained. That is complete BS. We have far better understanding of both the terrestrial and the ocean carbon cycle than that, more to the point, we know that the CO2 levels are increasing largely due to fossil fuels, because we can identify the fossil-fuel derived CO2 in the atmosphere: it has a different isotopic composition than CO2 from other sources. It doesn't help that all the theories say that a warmer planet will generate higher CO2 levels. Correlation != causation: we don't know whether the CO2 is causing the temperature or whether the temperature is causing the CO2. That is a pure lie. It is an inescapable physical FACT that CO2 causes warming. It causes warming regardless of how the CO2 gets there, too. We can demonstrate in the lab that both are possible, and that tells us nothing about which one is actually happening. Also dead wrong. We know that temperature increases can cause higher CO2 levels, e.g., by reducing the ability of the oceans to hold CO2. We also know that such CO2 will cause warming. And we also know that most of the CO2 increase over pre-industrial times originates from fossil fuel burning. That is a bare-faced lie. The fact that the planet has warmed and that CO2 is somehow involved in that is now beyond reasonable doubt. That is total and utter denial of facts. It is established beyond all reasonable doubt that the planet has warmed, and that anthropogenic CO2 is a significant contributor. The recent IPCC report is very clear on this: planet hotter, Yet you deny even that. causes uncertain (human-related causes "likely" to be a significant factor, but that could be anything from 1/10 to 9/10 of the problem), They do not say that it is anything from "1/10 to 9/10" of the problem, and they say directly that "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations". (In their jargon, "very likely" means "probability >90%".) solution impossible at current level of knowledge. The IPCC said no such thing. In fact, the SPM (the only document so far released) said nothing at all about solutions. The previous report did talk about solutions, and most certainly never said "a solution is impossible".
Nope. It is a forcing. Water vapor holds a higher concentration of the greenhouse effect then Co2 does and is more abundant in the air. And when the sun causes more water to evaporate, it causes more watervapor to be in the air wich causes more heat to be retained. In a models sence of wording, it would be the underlying force. And therby a forcing.
That's not what a forcing is. Water vapor causes warming, yes, but it is not a forcing, according to climatology jargon. I already gave you a link to an article explaining the difference in terminology (here)
I think it is clear you don't understand theworking here.
Don't lecture me on climatology. You've been making moronic statements about it which I have been patiently correcting for a month now.
The sun gets hotter. It evaporates more water and raises the air temperature. The increased humidity traps more water then something comes along and attached to it creating clouds. Now clouds block some of the light reducing the effects of the sun.
I know that. In fact, I explained it to you once. It still doesn't make water vapor a forcing.
No, the forcings due to contrails and such are largely independent of whatever the global warming is due to.
No, the paper like you, are trying to attribute the wrong information to the desired outcome.
No, it's basic physics. Contrails do not magically act differently if the temperature is being raised by CO2 or by something else. Contrails don't care what is causing the temperature increase.
How much stronger? The amount of heat caused by the increaded water vapor stronger?
The positive feedback from increased water vapor acts the same regardless of whether the water vapor increase is being produced by CO2-based heating or by Sun-based heating. Water vapor does not amplify solar heating more than it amplifies CO2 heating. It amplifies any heating in the same way. The forcing from solar variations is much smaller than the forcing from CO2. Water vapor amplifies both forcings, but the solar variation forcing remains much smaller because it started out much smaller.
It doesn't need to be that much stronger, the sun isn't the only factor in this.
Yes, it does need to be much stronger than it actually is.
The Co2 models discount a lot of these factors by negating watervapor effects in favor of making Co2 apear stronger.
Once again proving you don't know the first thing about climatology. Yet you presume to lecture others on it.
Climate models do not "negate" or "neglect" water vapor effects. All climate models include water vapor feedbacks. Those feedbacks act on ALL forcings in the system, not just CO2 or just anthropogenic forcings.
I'm saying let the science prove it out.
It has been. The fact that you refuse to accept it says more about your bias and ignorance than it does about the science.
There is and always has been a lot of support for the sun being the cause.
There isn't and there hasn't. The Sun has been ruled out as the major cause of global warming. Deal with it. It makes a contribution, but it's much smaller than anthropogenic factors.
With the sun, it will fic itself. With human caused GHGs we are fucked unless something drastic is done.
The Sun won't necessarily "fix itself" any more than GHGs will. Eventually the solar intensity will change, and eventually GHGs will get scrubbed from the atmosphere, but neither are necessarily going to happen on any time scale that's convenient for us.
(More accurately, the Sun gives a measurable but small contribution, and greenhouse gases give a measurable and large contribution.)
There is no way you can say this to any certanty.
Yes, there is. You simply refuse to accept
Try reading, say, anything from the entire climatological literature over the last 30 years. The fact that you choose to dismiss it does not make it any less credible.
Prove it.
Read the scientific literature. You can start by the references in the IPCC reports.
"we" didn't know enough just a few years ago, before knowledge of increased solar output caused scientists to adjust their numbers by up to 1/3rd,
Adjusting variance in solar output by 1/3 still does not come close to making solar variations a dominant effect.
again with global dimming, and again when the fact that plants and soil will emit some greenhouse gases when they are warmed.
Once again, none of those have come close to approaching anthropogenic CO2 in effect size. The fact that we have improved our estimates of natural forcings does not somehow mean that we suddenly don't know anything about their values or relative significance. It is not credible that there is some huge natural effect that we have simply overlooked. And even if there were some huge unknown warming effect, there would also have to be an even huger unknown cooling effect to cancel out the greenhouse effect, because you simply cannot escape the physical fact that anthropogenic CO2 produces substantial warming.
Somehow the climate models didn't pick-up that something was wrong with the numbers before those discoveries.
The adjustments are well within the error bars of the models, which is what matters. If the new values were outside the previous range of plausible uncertainty in the model estimates, then there would be a problem.
So I fail to believe there's been a world of improvement in just a few years.
Anthropogenic global warming was already established science "a few years ago" just as it is now; nothing has changed that.
I'd very much like to see a comprehensive summary of other possible causes, and any kinds of feedback loops on the planet, which may account for even more of the warming, and therefore adjusting the numbers for man-made warming even further.
Like I said, go read the scientific literature. It is vast. Are you under the impression that nobody has looked at other causes or feedbacks?
No, it isn't. What if most Earthquake "experts" predict California is going to fall off the face of the Earth, into the Pacific Ocean, within a year?
You can't support your point by making up an example of an obviously false scenario that "experts" all believe.
In the real world, most earthquake experts do not predict that, because it is extremely implausible.
How about if 9 out of 10 doctors believe you have a disease, for which there is no test, and where the knowledge of the disease is so poor that even the list of symptoms requires significant interpretation?
Again, fictional scenarios do not support your point. In the real world, 9 of 10 doctors will not tell you have a disease if they can't even test for it or know anything about it.
Perhaps we can restrict our discussion to real groups of experts, and not fictional groups of idiot strawmen.
No, it's irresponsible to defer all consideration to them,
Who would you prefer to defer consideration to?
particularly when it's understood that the science in the specific field is rather primitive,
It is not so primitive that it can't detect the huge effect of anthropogenic global warming.
they've made numerous mistakes in the recent past,
This is disingenuous. Any time science improves you can claim that the previous science was "mistaken" and therefore no science is trustworthy.
The fact is, estimates of the contributions of individual effects are continually improving, and the conclusions over the last 25 years regarding the significance of AGW have not changed; indeed, the evidence has continued to mount in its favor.
the scientific method doesn't apply well,
That is completely false.
and the current best-evidence has a huge margin of
It is certainly the case that the error bars get larger the farther back in time you go. But have [urban heat island effects] been accounted for sufficiently? IOW, how accurately can we measure such effects? I don't remember the latest estimates, but I do remember that the effect is no greater than 0.05 degrees, and may in fact be zero. I would thus estimate the error bars to be no larger than ~0.025 degrees. Extraordinary claims require extraordinary evidence. After more than 50 years of study, we have vast amounts of evidence. Today the extraordinary claim is that we are not affecting the climate, and requires analogously strong evidence.
(More accurately, the Sun gives a measurable but small contribution, and greenhouse gases give a measurable and large contribution.)
The simple fact is that temperature measuring technology that is actually used to measure the air within a useable temperature range is highly imprecise and highly inaccurate.
Got any data to back that up? I want to see the manufacturer specs on the actual equipment that has been used at the hundreds of temperature measurings stations around the world for the past 100 years or even 30 years. Go ahead and try to find that data.
If you want to assert that the accuracy and bias of temperature measurements is something other than what studies have shown it to be, it is incumbent upon you to demonstrate that — and even moreso, that these errors introduce a systematic upward bias into global temperature averages of a magnitude sufficient to render the observed global warming an artifact of measurement error.
Thermometer intercomparison studies do exist; I saw one cited in a similar Slashdot thread last month, which I've spent the last 20 minutes trying to find. As I said, if you want to dig around on Web of Science or Google Scholar long enough, you can find them too.
Most will only be able to measure temperature to within +/- 2C!
That is completely absurd. Even thermometers hundreds of years ago could accurately measure temperatures to better than 1 degree accuracy. Meteorological thermomenters in the 20th century are far more accurate.
And note again that the combined average of many thermometers are more accurate than any single thermometer.
I would love to know where you are getting these "facts".
This theory is so far from it that hardly anyone even bothers to talk about the uncertainties in that data.
Idiot. Read any paper on the instrumental temperature record and you will find discussion of the uncertainties in the data. Track the references back far enough and you will eventually find the calibration and bias estimation procedures used.
We seem to be assuming no human error whatsoever in the the recording of the temperature readings.
No, we do not. Human errors, both random and systematic, can be and are estimated. Search the literature for "bias correction", "cross validation", etc.
Such questions should at least be occuring to you. The fact that they are not makes me wonder about whether you really care about the truth.
I have not claimed that the instrumental temperature record has zero error. I merely claimed that the errors in the record are much smaller than the warming trend observed. The fact that you know nothing about how that record is calibrated and debiased tells me you certainly do not care about the truth.
I would sneer at the idea that it would mean the end of our species and openly laugh when you claim to have evidence that would prove it without the slightest doubt.
No one has claimed that global warming will "end our species". But the existence of global warming has been proved beyond reasonable doubt.
I would quite like an extra 5-10F increase at the lattitude where I currently live.
I doubt that you would, as temperature increase is far from the only effect of global warming. And nice of you to care so much about people at other latitudes.
Just means that there would be some migration away from equatorial regions.
Oh, yeah, "some" migration. I'm sure you would like to support the costs of that relocation, too, along with the social and political unrest which accompanies it. (More likely, you would prefer your fellow taxpayers, or ideally other countries altogether, support it.) Not to mention your complete lack of ethics in supporting climate change which results in the relocation of other populations which conveniently don't include you.
Actually all of them are. hehe. Okay. Sorry about that. Couldn't resist.
Not all of the world's population centers are located close to sea level at the ocean front,
We don't need to know anything about the past climate to know that natural effects are not the dominant contributor to climate change today. But if you want to include historical data, that only strengthens the case that the current warming trend is not natural. Ummm, from the historic temperatures which have always hit an upper limit of approximately the same value over and over again You will note that historically CO2 levels were nothing like what they are projected to become by the end of the last century.
Negative feedbacks do kick in eventually, so that temperatures will not grow without bound, but you cannot point to past trends without also pointing to the gross differences between the past and present climate.
Temperatures hit will hit a limit in the future as well, but the limiting temperature will be much larger when the climate comes into equilibrium with the much larger amount of CO2 that is now present. If we are perturbing the system, there seems to be only one real direction it can go. This is manifestly false, as (a) the Vostok data gives no indication of what happens to interglacials when CO2 concentrations are above 300 ppm, and (b) temperatures in previous geological eras far exceeded any interglacial period visible in the Vostok data.
Nobody is claiming that global warming is going to wipe out our species. Nor do we need a "death penalty" on combustion, or revert to pre-industrial civilization. We can abate CO2 emissions by changing power sources, developing more efficient technologys, changing consumption patterns, and so on. We do not need to eliminate emissions entirely to have a positive benefit.
Furthermore, if you want to claim that man is not the cause of global warming, and try to introduce a previously-unknown new warming effect, you also have to introduce an even bigger previously-unknown cooling effect to explain why greenhouse gas emissions aren't warming the planet even more, on top of this new warming effect. It's not credible. It suggests the Sun is a big contributer, which is an assertion made by those who deny-that-man-causes-global-warming. The fact is, the Sun is not a big contributor to global warming, and you don't need Mars to tell you that: we can measure solar output directly.
My own observation is that there is a logical fallacy. When deniers deny global warming, they refute man's role in global warming. I think both sides agree the warming is occurring---part of the natural cycle of the Earth's pattern. There was an ice age, after all. We've obviously warmed up quite a bit since then. I doubt cave men had a significant impact on climate then to be the culprit. But, I digress. Those who support the notion of man-made global warming respond by claiming that the denial extends to the existence of warming period. Another interesting point is by calling them 'deniers,' there is an implication that they refuse to accept the truth. That's right. As much as you want to paint deniers as noble and daring persecuted revolutionaries, the fact is, the existence of anthropogenic global warming is by now well established, and their counterarguments are not credible.
Abdussamatov is a crackpot, plain and simple. He has not offered bold new theories; he has not even related Mars's climate to Earth's in any causal way. He denies that the greenhouse effect even exists, which is manifestly incorrect. The fact that this body is named the IPCC instead of the IPCS (Intergovernmental Panel on Climate STABILITY) indicates a distinct political bias. Afterall, we are looking to undestand how our climate maintains STABILITY, not to point fingers at bad guys who "corrupt the earth to satisfy their avarice," right? What the hell are you talking about?
Our climate is changing, and they are looking to understand why it is changing. Our climate has stabilizing factors, but it still is changing, which is the whole reason why it is important for the issue to be studied. Finally, your reliance on CO2 as THE CAUSE ignores the fact that water vapor contributes much more significantly to greenhouse effects. Sigh. Not this nonsense again.
Water vapor contributes to most of the natural greenhouse effect on Earth. But that doesn't matter as far as global warming is concerned: global warming is the change in temperature since pre-industrial times. It correspondingly is attributed to the change in greenhouse gas concentrations since pre-industrial times. Most of the GHG increase is from manmade CO2, and so is most of the increase in temperature. Whether or not the leading contributor to global climate change is cyclic (sun, earth, astrophysics, weather, etc.) or caused by new concentrations of elements in the atmosphere (CO2, H20, etc.) the leading SOURCE of energy is the sun. It is BAD SCIENCE to ignore potentially NEW information just because it disturbs your politically neat wold view... No one is ignoring the existence of the Sun. Sheesh. Insolation is well studied, and changes in insolation are known to be too small to account for the observed warming, which is another reason why Abdussamatov is a crackpot. He hasn't produced any new reasons to believe that insolation is larger than was previously thought, he merely tries to deny the existence of the greenhouse effect or even that humans are responsible for the observed CO2 increase.
It was more than a single article, but it was still only a few articles. The most prominent was in Newsweek, and also one in Time.
In fact, despite the media scare in the 1970s, scientists were not predicting a coming ice age. The general idea was that natural effects were causing a cooling, but there wasn't enough information to tell whether manmade effects would offset that cooling (from the greenhouse effect), or contribute further to it (from aerosols and particular matter). After 10-15 years it became evident that they produce an overall warming. Also, much of the manmade cooling effect was removed with tighter pollution controls.
You can read more about the history of "global cooling" here, here, and here.
That being said, new studies by a single research group are always on shakier ground than the combined conclusions of an entire scientific community over decades of work. Guess what, scientists make mistakes. They have made mistakes on global warming, and continue to make mistakes. Scientists never claim global warming is a fact, they only speak to their own observations. Your first two sentences are correct, but pretty much any climatologists will tell you that global warming is a fact, and rightly so. It is beyond credibility at this point to deny that the Earth has warmed over the last 150 years. It's also no longer tenable to support the claim that humans had little to do with it.
The fact is, climate modeling is not that bad if you don't push its predictions past a century or so. Climate models do fit the observations, and it's not just overfitting; you can't get the models to fit any set of observations. In particular, you can't get models with only natural or only anthropogenic forcings to fit the observations; you need both. I also don't trust the accuracy of temperature measuring stations around the globe for the past 100 years. Now you're being ridiculous. Global warming is not even remotely an artifact of inaccurate temperature measurement. With the small (barely detectable by the limits of thermometer accuracy and precision) tempurature increases the earth is not going to become like venus in 50 years time. The temperature increases that have been measured are much greater than the limits of thermometer precision. And nobody is claiming that "the Earth is going to become like Venus in 50 years time". That's a strawman constructed to make concerns about global warming look absurd. Hell, it hasn't even been proven in any even remotely scientific way that increased average surface temperatures will have any significant negative effect on, well, anything. We know that plants would be happy. That's not wholly correct; it will, in general, encourage plant growth, but some species will suffer as the local climate changes alter their preferred climate, and crops can have decreased nutritional content even when their overall growth increases. Although, no doubt equatorial folks would be a bit miffed at having to deal with days that are a few degrees warmer on average. 5-10 degrees F warmer is quite possible and is nothing to sneer at, even in non-equatorial regions. And if sea levels really do rise the rich people who own ocean front homes will be a bit ticked off if they have several feet of seawater in their house. A great many of the world's population centers, and a number of entire nations, are close to sea level at the ocean front. It is not just "rich people's" problem. In fact, poor people will be disproportionately affected, as is usual.
You're also neglecting the damages and deaths from more extreme weather events, the consequences of droughts, disrupted ecosystems, fishing patterns, shifts in regional climate, new disease vectors, and so on.
I don't know what your point is. What is the "energy/heat cycle"? Are you claiming that nuclear power causes global warming? What negative effect is nuclear power supposed to have on the Earth.
Whether nuclear power ultimately derives from solar energy or not is largely irrelevant to any useful question about the utility of power sources.
There is rather less certainty regarding what the climate will do in the future, but we know enough to say that it will continue to warm at least to some extent. Personally, I'm quite saddened that the supposedly smart people here on
Fresh water freezes at 0 C in the lab. Dropping the temperature to 0 C obviously can never cause water to free in the real world.
We are talking about the laws of physics here, you know. The electromagnetic adsorption spectrum of CO2 does not somehow change in the atmosphere from what it is in the lab.
You can find calculations of how it contributes to temperature in climatology textbooks, or hunt around on the web (e.g. here). In the link above (an applet) notice how it looks like there were higher temperatures in previous interglacials? Yes, the temperature has been higher in the past. What is your point? I see a strong correlation with the CO2 that suddenly stops ( saturation?) Not saturation, just that the ice age cycles were being driven a lot by Earth's orbital variations as well as CO2. Above 280 ppm CO2 is the industrial period, where temperature is being driven mostly by CO2 alone.
Note that the industrial temperature/CO2 correlation is still there: the correlation does not disappear, it merely changes slope. In fact, the correlation between the two (measured by how well the data approximates a straight line) is much stronger than in the pre-industrial ice age cycles, meaning that the current temperatures are much more closely determined by CO2 levels than they have been in the past. There seems to be a lower and upper bound. The earth seems to be bouncing between two states, kind of like a Lorenz butterfly. If anything I would be more worried about us perturbing the 'orbit' of the system in such a way to send us into an Ice Age. Given the apparent dynamics of the system (2 strange attractors?) that would seem a much more likely danger. Umm, out of which thin air did you pull this latter conclusion from?
It's ok, they've got grad students doing it. They're expendable.
By the way, (if [the greenhouse effect] didn't exist, how could we make greenhouses?) The "greenhouse effect" referred to in global warming is different from how actual greenhouses work. The former has to do with absorbing infrared radiation from the Earth; the latter has to do with preventing convective cooling.