Got to run right now, but William Gray's claims are probably the most absurd of any of the ones you've cited so far. He basically says the warming is due to the meridional overturning circulation. That happens when the MOC strengthens. The problem is that the data indicate that, if anything, it has weakened. Moreover, the spatial pattern of temperature change doesn't look anything like heat transport to the North Atlantic. He's got no data at all to back himself up, and he's never published anything in the peer reviewed literature.
Your condescending claims about what I have and have not "sought" notwithstanding, the fact is that I am well familiar with most of the usual suspects you've been citing, and that "dissenting claims" which are demonstrably wrong don't really count.
No SUV's and coal-fired power plants back then dumping CO2 into the air, so why the warming/cooling fluctuations?
They're attributed mostly to solar and volcanic activity, explanations which notably fail to explain recent trends.
If you accept the fuzzy data saying we're on a long-term warming trend, then you must also accept the similarly-fuzzy data that says we're on a long-term cooling trend.
The two data sets are not similar. We've had a couple centuries of warming, including a recent period of accelerated warming associated with CO2 increases. There isn't any data that indicates a long term cooling trend.
Both have "facts" and data models backing them up.
This is your continued mistake of remaining ignorant of the data and theory, which allows you to claim that all claims about the climate should be weighted equally.
Even the vaunted IPCC had to fiddle with their data to make it look like we're on a long-term warming trend.
Cite the source for your accusation. The IPCC doesn't fiddle with data. They simply summarize already-published data.
Yes, it has been for a little while, but for the last few years it's been cooling. The warming models don't say how or why this should happen.
Cooling on the scale of a few years is not at all unusual in the presence of the rather large natural variability which exists on interannual time scales; you see short term deviations from the overall warming trend all the time in individual GCM runs. Short term above-average and below-average trends get smoothed out when you take the mean trend.
Yeah, those guys sound credible until you actually start reading the arguments in their papers. You're citing opinions, but the proof of the pudding is what kind of science they've got to support those opinions.
Lindzen's contribution to the effect of CO2 on climate is his "infrared iris hypothesis". It wasn't a bad idea on the surface, but it was demolished about 7 years ago in the literature upon comparing its predictions to data, and he hasn't come up with anything new on the climate sensitivity front since then. Indeed, most of his recent writings are unpublished rambling rants, not scientific papers.
Chylek's two recent publications on the sensitivity of the climate to CO2 are train wrecks of science. His first shot uses an inadequate 0D energy balance model which has a completely unrealistic treatment of the ocean transient response; anyone reputable in this field has been using models with 1D diffusive or upwelling-diffusive oceans for the last decade. Not coincidentally, he got that one published in the journal he edited. (In the same issue he also published a similar paper by Schwartz which was, if anything, even worse.) He also takes a very short and noisy time series, and doesn't do any uncertainty analysis on the trend or on the system response time — again, standard operating procedure for reputable work. His most recent work (still unpublished, AFAIK) doesn't even rise to the point of computing real trends; he throws out most of the data and picks a few peaks he happens to like (and doesn't do a real uncertainty analysis either, but that's the least of his problems).
Christy hasn't published much about the effect of CO2 on climate, except for one new paper this year. I confess I haven't yet read it, so I can't comment on it. I should bump it up on my reading list. Oh, there was also his model-data comparison of the tropospheric lapse rate, which notoriously used ensemble averages to represent models instead of ensemble run envelopes. (Basically, you're a lot more certain about the average of a bunch of data than you are about any particular realization, so if you go with the former you're going overestimate the model uncertainty and amplify the statistical significance of discrepancies.)
All these guys have been known to do good science in other areas, but that doesn't exempt them when they publish bad science, or good but wrong science.
Once you start working your way through the journals, you will find that not all opinions are created equal. You keep touting yourself as an impartial, rational skeptic, but until you invest effort in actually studying the science, you're not going to have an appreciation of where the real scientific debate lies.
Sadly, for your argument you've provided no proof whatsoever to back up your claims.
No, you've simply dismissed thousands of papers as biased, simply because they were cited in the IPCC report.
Yes, I have read quite a bit on the subject, but unlike you I've read arguments from both sides.
Says you. Please cite some of this literature you've read, by climate economists. I gave you a long list of noted climate economists who find otherwise.
And I hope you realize that a model being used to predict weather trends -- your "climate change catastrophe" if you will -- ought to be reliable enough to predict past weather trends as well. But it doesn't.
Climate models do reproduce past climate trends in temperature, precipitation, sea ice extent, etc., at global to sub-continental scales. They don't have skill for local climate. They do not predict "weather".
True, the information is a weak or invalid argument to the original claim but I did find a good hiding place for information that is very inconvenient to those who believe CO2 levels are so important to the greenhouse effect
The fact that water vapor provides most of the greenhouse fact is not "inconvenient" to the theory of CO2-driven global warming, and is in fact incorporated into all climate models with dynamical atmospheres.
Water vapor provides most of the ~30 C baseline greenhouse effect which prevents the Earth from being a frozen iceball. That does not contradict the physics which says that increases in CO2 levels can increase the greenhouse effect by a few more degrees.
Another poster pointed out that I mixed up the geologic epoch and was talking about something totally different than the original poster was. Although I suppose it's still marginally on topic since it has to do with methane emissions.
Very little. And we don't see a huge CO2 spike in the ice core records. They do produce some dust, but even in WWII, I really doubt that had global climatic effects. That's probably when the increase in aerosols took off due to industrialization, though.
Aw crap. I totally misread Permian as Paleocene, probably because I just read the Panchuk paper about methane clathrates... thanks. I shouldn't have been modded up.
Please post here the measured atmospheric carbon dioxide levels and global temperatures for that period in the 1940s that you mentioned.
Temperatures are here. For CO2, direct measurements didn't start until the late 1950s. You can see those here. Earlier than that, you have to look at ice cores (which also extend later than that, although nobody uses them for times when instrumental data is available). You can see those here.
If nobody can provide the data, I'm going to assume that this global warming stuff is all just alarmism, and not actually objective science at all.
That is a pretty silly statement. How paranoid do you have to be to believe that we don't even have data on global warming? It just shows how polarized the skeptics have become.
You're sort of right. I was vaguely trying to remember which parts of Africa got screwed for precipitation in the last IPCC report without looking at the figure. Looking at the figure, I was right: West Africa does get droughts; it's the Horn of Africa that gets most of the rain. But that's a multimodel ensemble average: more models predict drying than wetting. Looking at some of the individual studies, the results are more mixed. The paper you cite finds a band of heavier rain across the Sahel region of W. Africa, but right above and below it are bands of drought. A 2006 paper by Cook and Vizy finds more rain in W. Africa, but the eastern Sahel gets drought. Held et al. in 2005 indicate that the models lean towards more drying in the Sahel, though noting that models have traditionally had trouble with precipitation the Sahel region due to interhemispheric teleconnections with sea surface temperatures. I conclude that the rainfall patterns in this particular region are more unpredictable...
A warmer climate leads to more arable land and longer growing seasons.
Depends on where you are. If your plants are temperature limited in a temperate climate, maybe. If they're already in a warm climate, maybe not. And don't forget precipitation. When rain belts get shifted around, a lot of people end up unhappy.
CO2 is good - it is the world's best fertilizer.
This has got to be the most oversold benefit of CO2. CO2 fertilization helps, up to a point, if you have C3 photosynthesizers; C4 plants don't benefit. But direct manipulation FACE experiments show that this effect quickly saturates, and CO2 is often not the rate-limiting nutrient in photosynthesis; often it's water or nitrogen availability. The initial promise of CO2 fertilization hasn't really panned out; see here. It does help, but it doesn't quite help as much as one thinks, and it is often more than offset by negative climate changes.
Of course, all recent evidence points to warming having ended,
I hate to break it to you, but 10 years of below-average warming in a highly noisy system doesn't exactly overturn anthropogenic global warming.
and having been due to natural climate variability and/or solar cycles.
Natural climate variability counts against your claim, not for it. See the above: natural climate variability is quite large on short time scales, which makes short-term trends very unreliable evidence of anything. Over the long term, "natural climate variability" utterly fails to account for temperature trends over the 20th century; the only really long term cycles within the climate system itself are oceans, and the space/time pattern of ocean warming indicates the atmosphere is warming the ocean, not the other way around. Turning to external influences, there are solar cycles. Solar trends have been pretty much flat since the 1950s, and completely disagree with the warming experienced since then. They can account for some of the warming in the early 20th century, but very little of it since then.
Why do we have to be 100% sure? How about 95% sure? The point of removing CO2 is as an insurance policy against hazards which are likely but uncertain.
Anyway, the greenhouse effect is known to exist — without it, the planet would be frozen solid. The spectral absorption properties of CO2 are basic physics. CO2-induced warming can account for the observed warming, and other natural sources have failed to do so. Paleoclimate evidence shows examples in the past of large carbon excursions associated with dramatic warming. It's just not that questionable a theory anymore.
As for warming being bad, almost any climate change is "bad" if it happens comparatively rapidly, since nations and industrials are adapted to operating in a particular climate. 3+ degrees C of warming in a century is not slow. 3 C of cooling would be bad too. We would prefer a relatively stable climate. And with warming, there are serious abrupt changes that can be triggered if there's too much of it (ice sheet disintegration, large scale reorganization of ocean circulation, carbon cycle feedbacks, etc.), and we're not sure where the trigger is. Since we don't appear to have triggered those responses yet, it seems prudent not to move the climate too far, too fast from what we know is safe.
As for natural mechanisms to sink CO2, they're already failing to remove half of the emissions we generate, and that's almost certain to get worse as our emissions continue to grow rapidly. There are some feedbacks which can help (e.g., CO2 fertilization of plants), but there are also feedbacks that hurt (e.g., increased respiration from organic decay), and they are likely to be overwhelmed by the sheer quantities we're on our way to emitting.
First, this isn't a new idea. Artificial air capture of CO2 has been proposed for some time; a noted proponent of this idea is Klaus Lackner. I don't think this new group has made a huge breakthrough in the technology. The basic problem is that it's (a) expensive, and (b) you have to put the carbon somewhere.
As for (a), it's currently cheaper to just capture the CO2 at large point sources like coal plants. On the other hand, that only gets some of the emissions. While coal plants are the most serious source of CO2 right now, adding capture to power plants doesn't capture emissions from cars and other small sources. Still, right now it's easier to just make more fuel efficient cars than try to capture the CO2 they emit.
As for (b), the sequestration problem is shared by any carbon capture technology (air capture or not). The main solutions are to pump it into geological formations in land or under the sea, or to convert it to solid form. The latter is relatively expensive and energy intensive. Storing it in the deep ocean is difficult to do on a large scale. On land there are serious limitations on how fast you can pump CO2 into a formation without pressure fractures and leaks, and even then there is a wide variety of formations whose ability to store CO2 varies dramatically. It requires careful siting, monitoring, etc. and you still have to worry about leaks, not to mention all the legal problems with people worrying about the CO2 acidifying the groundwater and leeching out heavy metals.
That being said, I think this technology definitely needs a lot of R&D aimed at it, because though expensive and difficult, it's a fallback position to reduce CO2 levels if energy efficiency and alternative energy measures don't do enough of a job.
Regardless of whether we do something or we do nothing, we could have a global warming, a global cooling, or no change at all.
Sadly for your argument, the three cases are not equally likely.
I can see your economic education has been dismally incomplete.
Have you ever read anything ever published on the subject, Dr. Climate Economics? Go look at publications by Nordhaus, Tol, Yohe, Weitzman, Peizer, etc. They don't advocate measures which induce "crumbling economies". The point of mitigation is to mitigate what we can afford and adapt to the rest, not mitigate what we can't afford. We're still not even mitigating what we can afford, so the point is moot.
For every "melting North Pole" and "Greenland glacier" there's another story about a record snowfall, or a record winter, or some other similar-but-opposite climate phenomena.
I hope you realize that climate trends sustained throughout most of a century are quite different from random weather events. Distrust anyone who says that a particular cold winter is definitely due to global cooling, or a record warm summer is due to global warming. At best, you can only say whether such events are more or less common than they were 30+ years ago (and even then, attribution of local weather events is still hard). Look at long-term trends instead.
Please, go ahead and calculate the amount of volcanic activity necessary to melt several million square kilometers of ice. (Hint: latent heat of fusion is about 330 J/g.) It will be amusing to see how many orders of magnitude you're off by.
Another hint: we're not recovering from an ice age. Third hint: we already recovering from a mild cooling known as "the Little Ice age", and the natural source of warming which explain that recovery simultaneously fail to explain the 20th century warming trend.
Neither the 1940s nor the 1970s were the coldest years in the 20th century, globally speaking. The early 1940s were actually a temperature peak, followed by a drop. The cooling in the 1950s through 1970s is due largely to the cooling effects of industrial aerosol emissions (air pollution). (Funny, the skeptics like to bring up non-CO2 sources of climate change when it's convenient to them, but ignore other sources when it's not...)
Also, the 1940s and 1970s were not the years with the most CO2 in the air. CO2 has increased almost monotonically for the past 150 years, and is now higher than it has been in at least a million years.
Then why do I keep getting asked to completely change my lifestyle and to spend vast sums of money to buy more expensive "carbon neutral" products?
Oh yeah? Who is asking you to spend "vast sums of money", and exactly how vast are we talking here? That's quite at odds with the fairly modest carbon taxes recommended by mainstream economists or the IPCC, on the order of $30/ton C.
As for changing your lifestyle, we're talking simple energy efficiency measures, not living in a mud hut eating bark and leaves.
This report has been called into question not just by crackpots but by reputable climatologists from many countries and backgrounds.
Fine, name one main IPCC conclusion which is is significantly at odds with the majority of the scientific literature.
On the "overstating" side, the Wikipedia article you cite doesn't have anything even remotely specific, just generic accusations of "distortion". On the "overstating" side, there are positive feedbacks which the IPCC neglected, but it stated it was intentionally doing so because it couldn't yet quantify those risks.
These is just the first one I could come up with and I didn't even look hard.
Collapse of the meridional overturning circulation is probably the aspect of climate with which I'm most familiar, actually. It's rather fanciful to describe it as a "Little Ice Age", since it's mostly limited to the North Atlantic region, and continental European temperatures are predicted to increase overall under the large amounts of warming necessary to trigger another collapse (see, e.g., the 2005 GRL paper by Gregory et al.). (That is, there is cooling due to the collapse, but it's offset by global warming itself.) The real temperature drops occur over the ocean, not land, although there could be some cooling over Greenland and Scandanavia. And the real risks associated with a modern MOC collapse are not an "ice age", but a shift in the zonal precipitation bands changing how much rainfall countries get. The secondary risk is due to different countries warming at different rates, making an overall adaptation strategy difficult. This is discussed in the National Academies report that your link cites.
And I'll again point out to you the assumptions and data involved in the IPCC report have been called into serious question by noted climatologists.
Please, point out the "noted climatologists" who question the basic premises of AGW.
The IPCC also completely ignores the fact that their own models used to predict this coming catastrophe cannot account for past weather trends,
Climate models do not and cannot predict weather. They do account for past climate trends, most notably the 20th century global warming.
nor can it account for the current cooling trend we are now experiencing.
We are not experiencing a cooling trend under any meaningful definition of the word "trend". (Averaging over a few years does not constitute a trend.) At best you can say that temperatures have been fairly flat for about a decade. However, given the size of the interannual variability in temperature, you can't statistically say whether that's an actual trend or just weather noise. Depending on the size of the trend, it usually takes at least 20 years for a signal to definitively emerge from noise, which is why climatologists took several decades before they definitively stated that the warming we've seen is real.
An objective scientist would conclude that we know too little about the climate
An objective scientist would know something about statistics and conclude that a few years of data does not magically overturn a century's worth of study of the climate. For instance, there was an analogous period in the 1940s where climate was warmer than models hindcast, but nobody says that mea
I don't want my portfolio destroyed unless it absolutely must be destroyed to stop some life-threatening catastrophe.
Mitigating climate change doesn't require you to be personally bankrupted or for the global economy to be ruined. You might want to start by reading Bill Nordhaus's new book on climate economics. You can also read the summary of the IPCC AR4 WG3 report.
There are plenty of shades in between, but the point is that there are respected, reputable scientists on practically all sides of this issue.
That's not really true, it's an example of the success of the denialist publicity machine. There are legitimate points of debate, perhaps the most important of which is how strong are the climate feedbacks. The IPCC gives a climate sensitivity range between 1.5 and 4.5 C for a doubling of CO2, with a higher probability of being on the high side than the low side. This is supported by a rather large body of research both theoretically and observationally. The argument is over whether it's closer to the high or low side, and there is legitimate debate there, and it makes a big difference to policy. Likewise, there is legitimate debate over whether, say, hurricanes are being affected by global warming.
On the other hand, there is nobody respected and reputable who is seriously claiming that we are going to enter a new Little Ice Age. There's nobody serious who's saying that global warming hasn't happened. There are a few people who are hanging on to "the Sun did it", but solar trends are rather inconsistent with what has happened since the latter half of the 20th century, and it's just not really credible anymore.
While you're at it, submit a counter-argument to those who disagree with you, one that contains a point-by-point proof of where their models fail.
That's what the peer reviewed literature is for. It's already out there. People have been working on the relative attribution of natural and anthropogenic climate changes for decades now. Go into the IPCC AR4 WG1 report for a massive collection of references to studies.
No, 4 C for 2xCO2 is a figure that includes positive feedbacks. Actually, 3 C is the IPCC's best estimate, although they say it is most likely 1.5-4.5 C. Without any positive feedbacks, it's more like 1.1 C (see Schlesinger and Andronova's 2002 article "Climate sensitivity" in EGEC). Of course, there are plenty of positive feedbacks which exist, and those lead to the IPCC's estimate. However, there are some positive feedbacks that people worry about which the IPCC didn't include in their assessment, because they are difficult to quantify, including some potential carbon cycle responses and Greenland ice sheet dynamics.
How does this get +5 Insightful for saying nothing but "Real science agrees with me. I won't point you to any of it, but trust me, I'm right. P.S. AGW is a religion." How about some actual facts here? The only "facts" Troed has come up with in this thread are culled from skeptic web sites (which Troed doesn't even bother to cite), and are easily refuted by citations to the Real Science (TM) literature.
You really need to get out more. Seriously. Go read the journals. Look at the latest few issues of Science, Nature, Nature Geoscience, Journal of Climate, Geophysical Research Letters, Journal of Geophysical Research, Climate Dynamics, Climatic Change, etc. Count how many of the papers dispute the claim, "AGW is the cause of most of the warming in the past 50 years", or predicate their analysis on a contrary claim. Seriously. Go do it before coming back and telling us what the scientific community does and doesn't think. I read most of those journals regularly, and this huge skeptical controversy that pundits claim exists among climatologists, just doesn't exist. Yes, people disagree on things, such as the impacts of climate change on hurricanes. But the basic premise of AGW is widely accepted, and has been for some time now.
Sorry, but while you're stating quite a lot that really doesn't help since that's either your opinion or an unproven hypothesis.
Uh, no, it's basic physics. If you think the oceans have been warming the planet since the 1970s, they should be losing heat, but they are gaining heat. The heat penetration pattern indicates that the heat is coming from the surface, i.e. the atmosphere. This is in the Levitus paper I mentioned. If you look at the spatial pattern of temperature change which correlates with the PDO, it doesn't look like the overall temperature pattern, and the PDO-correlated warming is only a small fraction of the total warming. This is in the PDO review I mentioned.
There's only so long you can weasel out of the fact that you don't know any science and get all your knowledge of climate from skeptic web sites.
Science (as opposed to religion)
Yeah, you've got nothing. When all you can resort to is insisting that a scientific position is "religion", you've lost.
has no problems with competing hypothesises where testing and falsifiability are the means to find the better model.
The hypotheses you've proposed have been proven wrong, and the CO2 hypothesis has not. Deal with it.
You also seem to be very confused as to how the current thinking goes with solar influense
Oh yeah? Thinking like Foukal et al. in Science (2006?), or Stott et al.'s piece in J. Climate, or Lockwood and Froelich last year?
why do you believe the last 40 years aren't a good match?
Slashdot Mirror
Got to run right now, but William Gray's claims are probably the most absurd of any of the ones you've cited so far. He basically says the warming is due to the meridional overturning circulation. That happens when the MOC strengthens. The problem is that the data indicate that, if anything, it has weakened. Moreover, the spatial pattern of temperature change doesn't look anything like heat transport to the North Atlantic. He's got no data at all to back himself up, and he's never published anything in the peer reviewed literature.
Your condescending claims about what I have and have not "sought" notwithstanding, the fact is that I am well familiar with most of the usual suspects you've been citing, and that "dissenting claims" which are demonstrably wrong don't really count.
No SUV's and coal-fired power plants back then dumping CO2 into the air, so why the warming/cooling fluctuations?
They're attributed mostly to solar and volcanic activity, explanations which notably fail to explain recent trends.
If you accept the fuzzy data saying we're on a long-term warming trend, then you must also accept the similarly-fuzzy data that says we're on a long-term cooling trend.
The two data sets are not similar. We've had a couple centuries of warming, including a recent period of accelerated warming associated with CO2 increases. There isn't any data that indicates a long term cooling trend.
Both have "facts" and data models backing them up.
This is your continued mistake of remaining ignorant of the data and theory, which allows you to claim that all claims about the climate should be weighted equally.
Even the vaunted IPCC had to fiddle with their data to make it look like we're on a long-term warming trend.
Cite the source for your accusation. The IPCC doesn't fiddle with data. They simply summarize already-published data.
Yes, it has been for a little while, but for the last few years it's been cooling. The warming models don't say how or why this should happen.
Cooling on the scale of a few years is not at all unusual in the presence of the rather large natural variability which exists on interannual time scales; you see short term deviations from the overall warming trend all the time in individual GCM runs. Short term above-average and below-average trends get smoothed out when you take the mean trend.
Yeah, those guys sound credible until you actually start reading the arguments in their papers. You're citing opinions, but the proof of the pudding is what kind of science they've got to support those opinions.
Lindzen's contribution to the effect of CO2 on climate is his "infrared iris hypothesis". It wasn't a bad idea on the surface, but it was demolished about 7 years ago in the literature upon comparing its predictions to data, and he hasn't come up with anything new on the climate sensitivity front since then. Indeed, most of his recent writings are unpublished rambling rants, not scientific papers.
Chylek's two recent publications on the sensitivity of the climate to CO2 are train wrecks of science. His first shot uses an inadequate 0D energy balance model which has a completely unrealistic treatment of the ocean transient response; anyone reputable in this field has been using models with 1D diffusive or upwelling-diffusive oceans for the last decade. Not coincidentally, he got that one published in the journal he edited. (In the same issue he also published a similar paper by Schwartz which was, if anything, even worse.) He also takes a very short and noisy time series, and doesn't do any uncertainty analysis on the trend or on the system response time — again, standard operating procedure for reputable work. His most recent work (still unpublished, AFAIK) doesn't even rise to the point of computing real trends; he throws out most of the data and picks a few peaks he happens to like (and doesn't do a real uncertainty analysis either, but that's the least of his problems).
Christy hasn't published much about the effect of CO2 on climate, except for one new paper this year. I confess I haven't yet read it, so I can't comment on it. I should bump it up on my reading list. Oh, there was also his model-data comparison of the tropospheric lapse rate, which notoriously used ensemble averages to represent models instead of ensemble run envelopes. (Basically, you're a lot more certain about the average of a bunch of data than you are about any particular realization, so if you go with the former you're going overestimate the model uncertainty and amplify the statistical significance of discrepancies.)
All these guys have been known to do good science in other areas, but that doesn't exempt them when they publish bad science, or good but wrong science.
Once you start working your way through the journals, you will find that not all opinions are created equal. You keep touting yourself as an impartial, rational skeptic, but until you invest effort in actually studying the science, you're not going to have an appreciation of where the real scientific debate lies.
Sadly, for your argument you've provided no proof whatsoever to back up your claims.
No, you've simply dismissed thousands of papers as biased, simply because they were cited in the IPCC report.
Yes, I have read quite a bit on the subject, but unlike you I've read arguments from both sides.
Says you. Please cite some of this literature you've read, by climate economists. I gave you a long list of noted climate economists who find otherwise.
And I hope you realize that a model being used to predict weather trends -- your "climate change catastrophe" if you will -- ought to be reliable enough to predict past weather trends as well. But it doesn't.
Climate models do reproduce past climate trends in temperature, precipitation, sea ice extent, etc., at global to sub-continental scales. They don't have skill for local climate. They do not predict "weather".
True, the information is a weak or invalid argument to the original claim but I did find a good hiding place for information that is very inconvenient to those who believe CO2 levels are so important to the greenhouse effect
The fact that water vapor provides most of the greenhouse fact is not "inconvenient" to the theory of CO2-driven global warming, and is in fact incorporated into all climate models with dynamical atmospheres.
Water vapor provides most of the ~30 C baseline greenhouse effect which prevents the Earth from being a frozen iceball. That does not contradict the physics which says that increases in CO2 levels can increase the greenhouse effect by a few more degrees.
That doesn't have anything to do with the original claim that the CO2 greenhouse effect is saturated.
Another poster pointed out that I mixed up the geologic epoch and was talking about something totally different than the original poster was. Although I suppose it's still marginally on topic since it has to do with methane emissions.
That was my point!
Very little. And we don't see a huge CO2 spike in the ice core records. They do produce some dust, but even in WWII, I really doubt that had global climatic effects. That's probably when the increase in aerosols took off due to industrialization, though.
Aw crap. I totally misread Permian as Paleocene, probably because I just read the Panchuk paper about methane clathrates ... thanks. I shouldn't have been modded up.
Please post here the measured atmospheric carbon dioxide levels and global temperatures for that period in the 1940s that you mentioned.
Temperatures are here. For CO2, direct measurements didn't start until the late 1950s. You can see those here. Earlier than that, you have to look at ice cores (which also extend later than that, although nobody uses them for times when instrumental data is available). You can see those here.
If nobody can provide the data, I'm going to assume that this global warming stuff is all just alarmism, and not actually objective science at all.
That is a pretty silly statement. How paranoid do you have to be to believe that we don't even have data on global warming? It just shows how polarized the skeptics have become.
You're sort of right. I was vaguely trying to remember which parts of Africa got screwed for precipitation in the last IPCC report without looking at the figure. Looking at the figure, I was right: West Africa does get droughts; it's the Horn of Africa that gets most of the rain. But that's a multimodel ensemble average: more models predict drying than wetting. Looking at some of the individual studies, the results are more mixed. The paper you cite finds a band of heavier rain across the Sahel region of W. Africa, but right above and below it are bands of drought. A 2006 paper by Cook and Vizy finds more rain in W. Africa, but the eastern Sahel gets drought. Held et al. in 2005 indicate that the models lean towards more drying in the Sahel, though noting that models have traditionally had trouble with precipitation the Sahel region due to interhemispheric teleconnections with sea surface temperatures. I conclude that the rainfall patterns in this particular region are more unpredictable ...
A warmer planet is good.
Good for who? Norway? Or West Africa?
A warmer climate leads to more arable land and longer growing seasons.
Depends on where you are. If your plants are temperature limited in a temperate climate, maybe. If they're already in a warm climate, maybe not. And don't forget precipitation. When rain belts get shifted around, a lot of people end up unhappy.
CO2 is good - it is the world's best fertilizer.
This has got to be the most oversold benefit of CO2. CO2 fertilization helps, up to a point, if you have C3 photosynthesizers; C4 plants don't benefit. But direct manipulation FACE experiments show that this effect quickly saturates, and CO2 is often not the rate-limiting nutrient in photosynthesis; often it's water or nitrogen availability. The initial promise of CO2 fertilization hasn't really panned out; see here. It does help, but it doesn't quite help as much as one thinks, and it is often more than offset by negative climate changes.
Of course, all recent evidence points to warming having ended,
I hate to break it to you, but 10 years of below-average warming in a highly noisy system doesn't exactly overturn anthropogenic global warming.
and having been due to natural climate variability and/or solar cycles.
Natural climate variability counts against your claim, not for it. See the above: natural climate variability is quite large on short time scales, which makes short-term trends very unreliable evidence of anything. Over the long term, "natural climate variability" utterly fails to account for temperature trends over the 20th century; the only really long term cycles within the climate system itself are oceans, and the space/time pattern of ocean warming indicates the atmosphere is warming the ocean, not the other way around. Turning to external influences, there are solar cycles. Solar trends have been pretty much flat since the 1950s, and completely disagree with the warming experienced since then. They can account for some of the warming in the early 20th century, but very little of it since then.
Why do we have to be 100% sure? How about 95% sure? The point of removing CO2 is as an insurance policy against hazards which are likely but uncertain.
Anyway, the greenhouse effect is known to exist — without it, the planet would be frozen solid. The spectral absorption properties of CO2 are basic physics. CO2-induced warming can account for the observed warming, and other natural sources have failed to do so. Paleoclimate evidence shows examples in the past of large carbon excursions associated with dramatic warming. It's just not that questionable a theory anymore.
As for warming being bad, almost any climate change is "bad" if it happens comparatively rapidly, since nations and industrials are adapted to operating in a particular climate. 3+ degrees C of warming in a century is not slow. 3 C of cooling would be bad too. We would prefer a relatively stable climate. And with warming, there are serious abrupt changes that can be triggered if there's too much of it (ice sheet disintegration, large scale reorganization of ocean circulation, carbon cycle feedbacks, etc.), and we're not sure where the trigger is. Since we don't appear to have triggered those responses yet, it seems prudent not to move the climate too far, too fast from what we know is safe.
As for natural mechanisms to sink CO2, they're already failing to remove half of the emissions we generate, and that's almost certain to get worse as our emissions continue to grow rapidly. There are some feedbacks which can help (e.g., CO2 fertilization of plants), but there are also feedbacks that hurt (e.g., increased respiration from organic decay), and they are likely to be overwhelmed by the sheer quantities we're on our way to emitting.
First, this isn't a new idea. Artificial air capture of CO2 has been proposed for some time; a noted proponent of this idea is Klaus Lackner. I don't think this new group has made a huge breakthrough in the technology. The basic problem is that it's (a) expensive, and (b) you have to put the carbon somewhere.
As for (a), it's currently cheaper to just capture the CO2 at large point sources like coal plants. On the other hand, that only gets some of the emissions. While coal plants are the most serious source of CO2 right now, adding capture to power plants doesn't capture emissions from cars and other small sources. Still, right now it's easier to just make more fuel efficient cars than try to capture the CO2 they emit.
As for (b), the sequestration problem is shared by any carbon capture technology (air capture or not). The main solutions are to pump it into geological formations in land or under the sea, or to convert it to solid form. The latter is relatively expensive and energy intensive. Storing it in the deep ocean is difficult to do on a large scale. On land there are serious limitations on how fast you can pump CO2 into a formation without pressure fractures and leaks, and even then there is a wide variety of formations whose ability to store CO2 varies dramatically. It requires careful siting, monitoring, etc. and you still have to worry about leaks, not to mention all the legal problems with people worrying about the CO2 acidifying the groundwater and leeching out heavy metals.
That being said, I think this technology definitely needs a lot of R&D aimed at it, because though expensive and difficult, it's a fallback position to reduce CO2 levels if energy efficiency and alternative energy measures don't do enough of a job.
Regardless of whether we do something or we do nothing, we could have a global warming, a global cooling, or no change at all.
Sadly for your argument, the three cases are not equally likely.
I can see your economic education has been dismally incomplete.
Have you ever read anything ever published on the subject, Dr. Climate Economics? Go look at publications by Nordhaus, Tol, Yohe, Weitzman, Peizer, etc. They don't advocate measures which induce "crumbling economies". The point of mitigation is to mitigate what we can afford and adapt to the rest, not mitigate what we can't afford. We're still not even mitigating what we can afford, so the point is moot.
For every "melting North Pole" and "Greenland glacier" there's another story about a record snowfall, or a record winter, or some other similar-but-opposite climate phenomena.
I hope you realize that climate trends sustained throughout most of a century are quite different from random weather events. Distrust anyone who says that a particular cold winter is definitely due to global cooling, or a record warm summer is due to global warming. At best, you can only say whether such events are more or less common than they were 30+ years ago (and even then, attribution of local weather events is still hard). Look at long-term trends instead.
Please, go ahead and calculate the amount of volcanic activity necessary to melt several million square kilometers of ice. (Hint: latent heat of fusion is about 330 J/g.) It will be amusing to see how many orders of magnitude you're off by.
Another hint: we're not recovering from an ice age.
Third hint: we already recovering from a mild cooling known as "the Little Ice age", and the natural source of warming which explain that recovery simultaneously fail to explain the 20th century warming trend.
Neither the 1940s nor the 1970s were the coldest years in the 20th century, globally speaking. The early 1940s were actually a temperature peak, followed by a drop. The cooling in the 1950s through 1970s is due largely to the cooling effects of industrial aerosol emissions (air pollution). (Funny, the skeptics like to bring up non-CO2 sources of climate change when it's convenient to them, but ignore other sources when it's not...)
Also, the 1940s and 1970s were not the years with the most CO2 in the air. CO2 has increased almost monotonically for the past 150 years, and is now higher than it has been in at least a million years.
On the "overstating" side, there are positive feedbacks which the IPCC neglected
That should be "understating".
Then why do I keep getting asked to completely change my lifestyle and to spend vast sums of money to buy more expensive "carbon neutral" products?
Oh yeah? Who is asking you to spend "vast sums of money", and exactly how vast are we talking here? That's quite at odds with the fairly modest carbon taxes recommended by mainstream economists or the IPCC, on the order of $30/ton C.
As for changing your lifestyle, we're talking simple energy efficiency measures, not living in a mud hut eating bark and leaves.
This report has been called into question not just by crackpots but by reputable climatologists from many countries and backgrounds.
Fine, name one main IPCC conclusion which is is significantly at odds with the majority of the scientific literature.
On the "overstating" side, the Wikipedia article you cite doesn't have anything even remotely specific, just generic accusations of "distortion". On the "overstating" side, there are positive feedbacks which the IPCC neglected, but it stated it was intentionally doing so because it couldn't yet quantify those risks.
These is just the first one I could come up with and I didn't even look hard.
Collapse of the meridional overturning circulation is probably the aspect of climate with which I'm most familiar, actually. It's rather fanciful to describe it as a "Little Ice Age", since it's mostly limited to the North Atlantic region, and continental European temperatures are predicted to increase overall under the large amounts of warming necessary to trigger another collapse (see, e.g., the 2005 GRL paper by Gregory et al.). (That is, there is cooling due to the collapse, but it's offset by global warming itself.) The real temperature drops occur over the ocean, not land, although there could be some cooling over Greenland and Scandanavia. And the real risks associated with a modern MOC collapse are not an "ice age", but a shift in the zonal precipitation bands changing how much rainfall countries get. The secondary risk is due to different countries warming at different rates, making an overall adaptation strategy difficult. This is discussed in the National Academies report that your link cites.
And I'll again point out to you the assumptions and data involved in the IPCC report have been called into serious question by noted climatologists.
Please, point out the "noted climatologists" who question the basic premises of AGW.
The IPCC also completely ignores the fact that their own models used to predict this coming catastrophe cannot account for past weather trends,
Climate models do not and cannot predict weather. They do account for past climate trends, most notably the 20th century global warming.
nor can it account for the current cooling trend we are now experiencing.
We are not experiencing a cooling trend under any meaningful definition of the word "trend". (Averaging over a few years does not constitute a trend.) At best you can say that temperatures have been fairly flat for about a decade. However, given the size of the interannual variability in temperature, you can't statistically say whether that's an actual trend or just weather noise. Depending on the size of the trend, it usually takes at least 20 years for a signal to definitively emerge from noise, which is why climatologists took several decades before they definitively stated that the warming we've seen is real.
An objective scientist would conclude that we know too little about the climate
An objective scientist would know something about statistics and conclude that a few years of data does not magically overturn a century's worth of study of the climate. For instance, there was an analogous period in the 1940s where climate was warmer than models hindcast, but nobody says that mea
I don't want my portfolio destroyed unless it absolutely must be destroyed to stop some life-threatening catastrophe.
Mitigating climate change doesn't require you to be personally bankrupted or for the global economy to be ruined. You might want to start by reading Bill Nordhaus's new book on climate economics. You can also read the summary of the IPCC AR4 WG3 report.
There are plenty of shades in between, but the point is that there are respected, reputable scientists on practically all sides of this issue.
That's not really true, it's an example of the success of the denialist publicity machine. There are legitimate points of debate, perhaps the most important of which is how strong are the climate feedbacks. The IPCC gives a climate sensitivity range between 1.5 and 4.5 C for a doubling of CO2, with a higher probability of being on the high side than the low side. This is supported by a rather large body of research both theoretically and observationally. The argument is over whether it's closer to the high or low side, and there is legitimate debate there, and it makes a big difference to policy. Likewise, there is legitimate debate over whether, say, hurricanes are being affected by global warming.
On the other hand, there is nobody respected and reputable who is seriously claiming that we are going to enter a new Little Ice Age. There's nobody serious who's saying that global warming hasn't happened. There are a few people who are hanging on to "the Sun did it", but solar trends are rather inconsistent with what has happened since the latter half of the 20th century, and it's just not really credible anymore.
While you're at it, submit a counter-argument to those who disagree with you, one that contains a point-by-point proof of where their models fail.
That's what the peer reviewed literature is for. It's already out there. People have been working on the relative attribution of natural and anthropogenic climate changes for decades now. Go into the IPCC AR4 WG1 report for a massive collection of references to studies.
No, 4 C for 2xCO2 is a figure that includes positive feedbacks. Actually, 3 C is the IPCC's best estimate, although they say it is most likely 1.5-4.5 C. Without any positive feedbacks, it's more like 1.1 C (see Schlesinger and Andronova's 2002 article "Climate sensitivity" in EGEC). Of course, there are plenty of positive feedbacks which exist, and those lead to the IPCC's estimate. However, there are some positive feedbacks that people worry about which the IPCC didn't include in their assessment, because they are difficult to quantify, including some potential carbon cycle responses and Greenland ice sheet dynamics.
How does this get +5 Insightful for saying nothing but "Real science agrees with me. I won't point you to any of it, but trust me, I'm right. P.S. AGW is a religion." How about some actual facts here? The only "facts" Troed has come up with in this thread are culled from skeptic web sites (which Troed doesn't even bother to cite), and are easily refuted by citations to the Real Science (TM) literature.
How about some standards here?
You really need to get out more. Seriously. Go read the journals. Look at the latest few issues of Science, Nature, Nature Geoscience, Journal of Climate, Geophysical Research Letters, Journal of Geophysical Research, Climate Dynamics, Climatic Change, etc. Count how many of the papers dispute the claim, "AGW is the cause of most of the warming in the past 50 years", or predicate their analysis on a contrary claim. Seriously. Go do it before coming back and telling us what the scientific community does and doesn't think. I read most of those journals regularly, and this huge skeptical controversy that pundits claim exists among climatologists, just doesn't exist. Yes, people disagree on things, such as the impacts of climate change on hurricanes. But the basic premise of AGW is widely accepted, and has been for some time now.
Sorry, but while you're stating quite a lot that really doesn't help since that's either your opinion or an unproven hypothesis.
Uh, no, it's basic physics. If you think the oceans have been warming the planet since the 1970s, they should be losing heat, but they are gaining heat. The heat penetration pattern indicates that the heat is coming from the surface, i.e. the atmosphere. This is in the Levitus paper I mentioned. If you look at the spatial pattern of temperature change which correlates with the PDO, it doesn't look like the overall temperature pattern, and the PDO-correlated warming is only a small fraction of the total warming. This is in the PDO review I mentioned.
There's only so long you can weasel out of the fact that you don't know any science and get all your knowledge of climate from skeptic web sites.
Science (as opposed to religion)
Yeah, you've got nothing. When all you can resort to is insisting that a scientific position is "religion", you've lost.
has no problems with competing hypothesises where testing and falsifiability are the means to find the better model.
The hypotheses you've proposed have been proven wrong, and the CO2 hypothesis has not. Deal with it.
You also seem to be very confused as to how the current thinking goes with solar influense
Oh yeah? Thinking like Foukal et al. in Science (2006?), or Stott et al.'s piece in J. Climate, or Lockwood and Froelich last year?
why do you believe the last 40 years aren't a good match?
Read the papers I cited.