Statements like this are not only diatribe, but impossible to prove. Uh, no. This is very uncontroversial atmospheric science; not even the most rabid of the skeptical climate scientists contest that.
You need to pick better battles here. Arguing from a position of limitless ignorance is not a good strategy for you.
We would need about 50 such platforms operating continuously for about 300-400 years to even start getting a feeling for CO2 recycling rates in the Atmosphere. Wow, more made-up numbers. 50 platforms. 300 years. Let's see that calculation. Considering that you apparently don't know anything at all about CO2 sink rates, this should be amusing.
I also didn't say Pinatubo emitted CO2. I said a Volcanic eruptions LIKE pinatubo CAN emit BOTH gases. I was being generous; volcanic emissions of other greenhouse gases are even more insignificant than CO2. In fact, entire world total emission of all greenhouse gases from volcanism is insignificant compared to other sources.
On the other hand, the aerosols and aerosol precursors which produce cooling are significant, but as I said, they drop out quickly.
There is a reason why Pinatubo produced global cooling and not global warming, you know.
I can't speak for the mainstream media, but you can try looking at studies of regional warming, e.g. here. The scenario studied leads to an increase of 1-5C in the maximum summer temperatures, in different regions of the U.S. Of course, this is not actual "data", it is a model prediction. It's not immediately clear to me which global warming scenario they were using, however.
How much data do we have on Sun activity over these years? We have pretty good data over most of the 20th century, some direct and some inferred by sunspots, which are a good proxy.
I am not talking about "brightness of the sun," either. Brightness is visible spectrum, and does not necessarily correspond to heat, etc. We're talking about total power output here; the power in each portion of the spectrum is easily derivable since the Sun is a good blackbody.
Have other planets experienced a similar level of warming? We have very little data on that.
How about water vapor in the atmosphere? From what I've read, water vapor is a strong contributor to global warming. Water vapor is hard to nail down exactly because so many processes affect it, but we know that increases in water vapor aren't responsible for most of the warming. Water vapor is more of a problem when making predictions of the future.
Even if we all switched to fuel cell vehicles and "growing" our fuel, we will then be putting large amounts of water vapor into the atmosphere from these technologies. Yes, that is a concern. (See here, although a subscription is unfortunately required.)
How about the fact that there are a lot more man made lakes? How about more people/cities? How about the fact that there are more plants and trees (phoenix AZ used to be a desert)? Yes, changes in land use patterns do have an effect on climate, and this has been studied intensively.
How about salt levels in the Oceans? What about salt levels in the oceans?
How do we really know that global warming is caused by mankind? The short answer is, because we are unable to quantitatively explain the warming without appealing to the effects of mankind's CO2 emissions. There is a much longer answer justifying the reasons why we can now be confident in that attribution.
And if you work for an academic institution, and you write a scientific report that goes against the current "consensus", then you get fired, and they threaten to send you to jail. Really? When has that happened?
Nothing we do at this point will have any effect on climate change for the next 30 to 40 years. Unless you want to be really extreme and start geoengineering...
Which one retrodicts Leif Ericsen finding grapes in Vinland? There are not enough paleo data to run a GCM that far back. Fortunately, you don't have to run a GCM that far back in order to say something about the next century.
Some control runs of GCMs on paleo data have been run just to see how they do, although their accuracy on such data is obviously going to be much worse than their accuracy for future prediction based on modern instrumental datat. Those runs indicate that GCMs can get mean trends decently well, but underestimate the decadal variability in temperatures.
Which one retrodicts the Maunder minimum? Now you're being ridiculous. GCMs predict terrestrial climate, not solar physics. Solar physics is an input to GCMs, not an output. If you want to talk about the reliability of solar models, that is a completely separate issue.
My point is that the past has examples of climate variation comparable to present climate variation. These past variations cannot reasonably be considered anthropogenic. The argument that the current variation must be anthropogenic because GCMs can be tuned to predict it from human inputs is weakened by the GCMs' inability to model these past variations. You are failing to distinguish between "the model predicts the wrong climate because it is inherently flawed", and "the model predicts the wrong climate because there isn't good data you can feed into it, so you get GIGO no matter how good the model is".
GCMs do hindcast well back to pre-industrial times. There is also the fact that you can't get GCMs to produce the observed warming without anthropogenic input under any kind of reasonable tuning. Anthropogenic forcings are a huge signal that you can't just explain away with a few minor tweaks here and there.
Um, science is full of predictions based on models. If you didn't have models, you couldn't make predictions at all. Models are not perfect, but they are based on known physics and do produce reasonable results in validation studies; GCMs do not "get the past wrong", unless you push them much farther than what they're being used to predict in the first place.
I guess reading comprehension wasn't one of your strong points. Or maybe math... You don't even have to read the linked articles to see that you're full of shit. I would call ">90% probability" to be "not in doubt".
Damn, you contradict yourself in the same paragraph... Point out the contradiction, then. I said that climate isn't correlated with absolute concentrations of CO2, because of all of the other climate factors in effect. Changes in climate are correlated with changes in CO2. You do understand the different between "absolute magnitude" and "change in magnitude", do you not?
CO2 was around 4400 PPM at that time. As I said, you cannot predict a temperature knowing only CO2 concentration, without also knowing what all the other climate forcings are. CO2 may have been 10x higher, but many other factors in the climate were also different: albedo, aerosol content of the atmosphere, concentrations of other greenhouse gases, and so on.
You can, however, predict that an increase in CO2 will produce an increase in temperature and vice versa, to a limited extent. (Too much change produces nonlinear feedbacks.)
If you had even bothered to read what I provided for you, you would have seen that having a large polar land mass and a continent that stretches between the poles as we have today is an essential ingredient to ice ages. I am trying to imagine why you believe that is relevant to global warming, even if it were true. (Incidentally, there have been plenty of ice ages with the continents as they are now.) Or how it contradicts my statements (e.g., that a drop in CO2 can precipitate ice ages, and increases can end them).
The only man-made activity that might change that is the Panama canal. Once again, what is your point? That manmade activity can't produce ice ages? (And no, the Panama canal will not change that.)
You cannot possibly be suggesting that a computer scientist at the University of New South Wales knows more about the climate than a research professor and State Climatologist with a Ph.D. from the University of Wisconsin-Madison. Fine. Just ignore Hansen, Schmidt, and all the other rebuttals too. Whatever it takes to preserve your worldview.
Put in random data, still get a hockey stick. So, your response is to ignore the flaws in their analysis and repeat your original claim. "I don't need facts! I know the truth!" That's some devastating logic there.
They obviously have a financial, if not ideological, incentive to predict doom and gloom. Fine, please point to where existing studies have been intentionally fudged their published conclusions to "doom and gloom".
Note also that scientists have an even stronger incentive to publish correct results. Scientists are rewarded for proving each other wrong. If you fudge your study, people will point it out: they get far more immediate reward from doing so than a vague "well, this one paper might someday influence in some way my own climate funding".
This is not to mention the whole process of tenure, which provides immunity against getting fired for your conclusions, once you make it that far.
Finally, the sharpest scientists are the ones least susceptible to having their careers jeopardized under putative punishment for coming to the "wrong" conclusions: they are pretty much guaranteed funding no matter what they publish.
Global Warming is a theory which can not be "proven" through experimentation, and the only way to demonstrate that it is valid is to show that there exists no other plausable explaination for the current state of our climate (I presume you are referring to anthropogenic global warming.)
Right now, there is no plausible explanation for the current stat of our climate that does not include significant influences from human activities.
Currently, there is little focus on producing other plausable explainations and existing inconsistencies (like the correlation between sunspot activity and global temperature) are not being explained in the Global Warming camp Global temperature is correlated with sunspot activity: the solar cycle has a detectable influence on the climate. It's detectable, and small. Well, not insignificantly small, but significantly smaller than anthropogenic influences. There are some good papers on this, starting with the 2006 Nature paper of Foukal et al., and also Stott et al.'s 2003 paper in J. Climate.
I don't know what is your basis for claiming that other explanations or inconsistencies are not being studied. Have you actually ever picked up a climate journal?
The vast bulk of the "Climate Change Science" has been funded by left leaning foundations and think tanks. Like the National Science Foundation? I think you are rather confused as to where the climatology community gets its funding.
The climate has not been studied long enough or with enough precision to predict with much confidence what is going to happen in the medium to long term. That depends on what you mean by "medium" and "long". The climate can be predicted with rough accuracy out to a century or so. A lot of the uncertainty is actually about what humans will do in response to global warming.
The Little Ice Age and the Midieval Warm Period are good examples of times when making predictions based on a couple of hundred years worth of data would produce conclusions unsupported by what we know happened thereafter Predictions are not based on just extrapolating a past trend, you know. They also involve modeling the physical processes involved in climate. You can't just point to some part of a time series where there was a variation from the normal and claim it is inherently unpredictable. On the basis of time series analysis alone, it would be. On the basis of physics, it's a different matter.
consensus of thought by people making predictions based on inadequate data in complex systems they don't understand will yield policy decisions that will seem laughable in the fullness of time. That may be true, it may be not, but policy has to be driven by one's best judgement at the time, not hindsight. "Doing nothing" is also a policy choice with potential consequences; it is not logically the default decision one should make in the absence of perfect certainty.
For every paper you can point to, I can point to another paper that contradicts your findings.
Go ahead, try.
We do not have the data to support human induced climate change.
We have more than enough data. We know how much human-induced CO2 there is, we know how much heat that retains, and there simply are not enough cooling effects in force to counteract it.
Remember Mount Penetubo in the early 1990's?
I was speaking of global warming, which is a century scale trend of increasing global temperature. Pinatubo caused a temporary cooling. Volcanoes do not contribute substantially to warming, except in scenarios like the snowball Earth where there isn't anything to take their emissions out of the atmosphere and they build up over millions of years. Over hundreds or even thousands of years, and with an active carbon cycle, they are irrelevant to warming.
By far vulcanism and solar intensity drive long term and short term climate variations.
They can drive both. However, the forcing due to solar variations over the last 150 years has been small compared to that of anthropogenic CO2, and the forcing due to vulcanism over that period of time is utterly negligible. Even over longer periods, solar variations have usually not been the main driver of climate; volcanism sometimes has been, at the ends of ice ages.
The only reason why it isn't undisputed yet is because we do not have the proper sensor gear in orbit around the earth to measure greenhouse gas sources in the oceans. That is a MAJOR gap in our understanding of how climate change works.
Greenhouse gas sources in the oceans are relevant to predicting climate change in the future, to estimate how much gas the oceans may source or sink. However, greenhouse gases in the oceans do not drive climate change; only gases in the atmosphere do. There are two questions here: is manmade CO2 driving global warming, and what will happen to the climate in the future. We have enough information to answer the first question in the affirmative, because it depends only on the historical atmospheric concentrations of CO2. Oceanic GHG concentrations are relevant to answering the second question. You cannot use uncertainty in oceanic GHGs to deny the fact that the global warming which has happened so far is primarily due to human influences.
The oceans cover 75% of the surface of the planet. We don't know Jack whats going on down there either.
That turns out to be incorrect; we know a great deal about what is "going on down there", including GHG concentrations. The uncertainty is about what will go on down there in the future.
So I think I am going to stick with Global warming can be blamed on oceanic vulcanism both for source gas emissions and also water temperature impacts
This can be disproven directly. As for source gas emissions, as I said before, GHG emissions from volcanos are measurable and are a tiny fraction of the increased GHGs that are in the atmosphere. Volcanic CO2, for instance, is emitted at a rate about 1-3% that of human emissions.
Even if it were impossible to estimate volcanic CO2 emissions (which it is not), we can measure directly how much total CO2 there is, and we can also measure directly how much of it is due to fossil fuel burning, and the latter is a huge contributor no matter how you choose to attribute all the natural sources.
As for ocean temperatures, that claim is even more ridiculous. Undersea volcanism cannot put out anything near the amount of heat necessary to produce global warming, and would also produce sea temperatures that are far higher relative to atmospheric temperatures than they actually are. Where did you get that idea, Iceagenow.com?
Your arguments only sound plausible as long as you ignore the actual numbers involved.
There are tons of direct evidence to relate solar activity in deep time to climate change using ice core data....data which was collected before we got here.
Of course there is evidence of the influence of solar variation on the climate, but that evidence does not indicate that changes in the Sun's output have "far more" influence on the climate than man "ever will". The largest contributors to climate change have been things like orbital variations, changing greenhouse gas concentrations, changing albedo, etc.
I would also like to point out, that I do not think it is coincidence that the earth is warming during a time when scientists are describing some of the most intense flare ups of solar activity since indirect/direct measurement began of space weather in the past 80 years.
Recent variations in solar intensity are larger than they have been in the early 20th century, but what is important to the climate is not whether the variations are larger than usual, but how much greater the Sun's total intensity is than usual. The fluctuations, while larger compared to other fluctuations, are still very small changes in the total luminosity. If you work out how much change in temperature can be produced by that much change in insolation, it turns out not to be sufficient to explain the majority of global warming. (It can explain some, perhaps 15% to at most 30%, and probably closer to the former than the latter.) In fact, solar variations are worse at explaining the warming over the last 30 years than they are at explaining warming earlier in the 20th century. You can read about that in Foukal et al.'s 2006 Nature paper, or Stott et al.'s 2003 paper in J. Climate.
Point out just one study everyone agrees that man has changed the climate. You can't find one, in the scientific literature.
That statement is so absurd I don't know how to respond to it. You can only conclude that man has not changed the climate if you ignore everything we know about the climate.
All of the studies I have seen make extremely large assumptions about cause and effect,
On the contrary, they work directly off of observational data and known laws of physics. There are uncertainties in parameters, but they are not so large that we cannot attribute effects to causes.
and no one has been able to model these effects to produce the changes we see in the earths climate at the moment.
That's also false. Models do reproduce post-industrial climate change.
Like I said before, these so called "scientists" advocating climate change by man, can't even design a weather model that predicts or acccurate describes any future weather pattern we see on a daily basis without weather sat info.
I already pointed out at least two ways in which that statement is stupid: climate is not weather, and it makes no sense insist that scientists predict things without data such as satellites.
Which besides Solar activity I think there is plenty of evidence in the fossil record and today, to suggest volcanism is playing a role in the earths warming as well and is the second major factor in climate change.
On the contrary, we know that the total contribution of volcanoes — both land and oceanic — to the climate is not very significant, other than the occasional dumping of aerosols producing a temporary cooling. Volcanos produce almost no warming. Furthermore, we know that the vast majority of CO2 increase is due to fossil fuel burning: we can measure that directly from its isotopic signature.
Let me get this straight. You are claiming that predicting small weather patterns, or localized weather phenomina, has no correlation and is of no help in predicting large scale climate change?
Yes. The weather cannot be predicted farther than two weeks in advance, even in theory, due to limitations imposed by chaos. Thus, weather prediction
That's what I disagree with. CO2 levels and global temps have never tracked over 600 million years.
As I said, you cannot predict global temperature from CO2 level alone. Your statement would only be meaningful if all aspects of the climate other than CO2 were the same historically as they are now, but that is far from the case.
It is only in modern times that we have determined enough about the other natural forcings to be able to isolate the warming contribution of CO2 from other effects.
I agree that a 20X increase in CO2 isn't as big as it sound (I'm arguing that it has a minimal effect even at that level), but if a 30% increase is enough to raise temps up to 4.5 degrees C in a short time, according to the IPCC, why wouldn't a 20X increase increase temps by an equivalent amount?
First, the IPCC doesn't predict that a 30% increase in CO2 produces a 4.5 degree warming; that's the upper bound figure for more like a doubling in CO2.
A 20x increase in CO2 certainly would produce significantly more warming than a doubling, but as I said, CO2 is far from the only contributor to the climate.
The fact seems to support my argument more than yours, because, if it's logarithmic, maybe a 30% increase in CO2 is completely negligible and you have to get increases of 2000X (guessing again) or more to see a difference.
Making numbers up out of thin air does not support your point.
Logarithmic curves are a great magnitude equalizer; any kind of doubling produces the same amount of warming. So an increase from 1 to 2 ppm theoretically produces the same warming as an increase from 1000 to 2000 ppm.
(This sounds absurd, and to some extent it is, because the actual curve is not perfectly logarithmic, although it is logarithmic for concentrations around 100-1000 ppm. It flattens out at even higher concentrations because of all the extra feedbacks that start kicking in.)
What exactly do you doubt, here? Do you doubt that the amount of sunlight trapped by a given concentration of CO2 can be calculated accurately? That is actually one of the easiest things to calculate, and the amount of heat retained by the atmosphere is more than enough to explain the current warming. If you want to propose an alternative, you not only have to come up with a different mechanism for warming (solar variations doesn't work for reasons already explained), but you also have to come up with extra large cooling mechanisms too, to explain what is countering all the CO2. Claiming that CO2 just doesn't cause that much warming is not an escape; it follows very simple and laboratory-testable physics of radiation adsorption.
I think much of the increase in CO2 over the millennia is caused by the huge increase in lifeforms.
What increase? Over what period of time? You mean, the last 20,000 years (here)? What increase of lifeforms are you talking about here?
Incidentally, it is certain that the major increase of CO2 over the last 150 years is due to fossil fuel burning, since that leaves a unique isotopic signature that can be detected.
My understanding from discussing GW with others is that CO2 from volcanoes has little impact on the climate because it can't get high enough into the atmosphere to make changes.
Over the short term, that's true, but in the "snowball Earth" scenarios, it's the primary mechanism by which the Earth can melt: with so much ice, the oceans can't take up much CO2, and over millions of years enough accumulates to thaw the planet.
As for other aerosols, over a half billion years, don't you think we'd have several cases of CO2-driven warming?
We surely do; this is most visible over the last million years in the Vostok cores.
As I've mentioned before, that Appalachian Mountains theory flies in the fact of other theories that have pretty g
I am not a big believer in the evidence for Human climate change. You can pull ice cores from the antarctic and find that the sun has far more influence on climate than man ever will. Ice cores don't actually indicate that, unless you mean the theory that perturbations in the Earth's orbit around the Sun affect the sunlight it receives.
Regardless, it's still a specious argument. There are many things that have had more influence on the climate than humans have. But that doesn't mean that the climate change caused by humans is of negligible impact on on human societies.
Unlike climate which has changed and will change long after we are gone, the number of species that are extinct and can be easily shown to be so through direct human action is far more convincing than climate change from scientists who cannot even forecast the weather properly even today without actually a camera in space looking at where it is going to rain tomorrow, let alone what cliamet will be in 10 -20 or even 30 years. That is, again, a specious argument; predicting the weather is a very different problem from predicting the climate. Furthermore, why do you bring up being unable to predict the weather without satellites and such? Of course you can't predict much if you have no data. But in the real world, we do have data.
You are also comparing apples and oranges; you point out observational evidence of species extinction, and then turn around and compare it to predictive power in the future. Of course prediction is harder than observation. Try comparing observational evidence of species extinction to observational evidence of man's past and present influence on the climate.
Climate is really not the root cause. The earth has been MUCH warmer in the past, and much colder, without any people around so get over it. The fact that the Earth has been warmer and colder in the past has nothing to do with whether climate change is good for us as a species.
All that being said, I agree that biodiversity and other environmental issues are serious problems in themselves, and not ones that are being helped by global warming.
CO2 is a greenhouse gas, one of many trace greenhouse gases in the atmosphere. It effects the climate, but that effect is minimal. Mess with the concentration of water vapor in the atmosphere, then you have a major effect on climate. The effect is minimal compared to the total contribution of water vapor, but compared to "able to change the temperature by a few degrees", the increases in CO2 concentration from pre-industrial times is not minimal.
Please explain what other forcings might possibly counteract high global temps being caused by CO2 levels 17.5 times higher than today's levels. First, a 20x increase in CO2 concentration is not as big as it sounds, because the climate sensitivity is logarithmic in CO2 concentration; it doesn't imply, for instance, a 20x increase in temperature. It is, however, still big compared to anthropogenic contributions. If you're talking about a period when global temperatures were comparable to today's values, like the Ordovician, please remember that was an ice age. The Earth's albedo was significantly than it is now, implying less retention of the Sun's heat. Other greenhouse gases, many of which (as you pointed out) are more efficient at trapping heat, may have been less prevalent. There could have been many more aerosols in the atmosphere from volcanism. There are all kinds of effects which can contribute majorly to cooling. But one of the best theories is the one you dismissed: the ice age actually occurred when CO2 levels dropped, setting off positive cooling feedbacks.
"I'm sorry, you cannot on the one hand claim that the climate is insensitive to changes in CO2, and then claim that CO2 doesn't impact the global climate."
I meant to say "does impact". IOW, yes, you are claiming that CO2 doesn't impact global temperatures.
And I have not claimed that CO2 doesn't impact global temps, You claimed that the climate is insensitive to CO2 concentration, which is not the case. I'm sorry, you cannot on the one hand claim that the climate is insensitive to changes in CO2, and then claim that CO2 doesn't impact the global climate.
it's just that historically, the record shows that global temps do their own thing, regardless of what the CO2 levels are doing. That is rather irrelevant to the issue of what CO2 is doing to global temperature today. And anyway, historically, we don't know what any number of other climate factors were, so we can't isolate the CO2 contribution from them.
Of course, since the IPCC is claiming a 30% increase in CO2 will cause a 2 to 4.5 degrees C jump in temps, when CO2 levels were at 7000 ppm, global temps must have been around (guessing) 500 degrees C, right? That argument, as well as all of the other arguments you are making here, are predicated on the same mistake, which is that you cannot infer absolute temperatures from absolute CO2 concentrations unless you know a great deal about all the other climate factors. We know a lot about them today, but not much about them hundreds of millions of years ago. You simply cannot conclude that X amount of CO2 means Y temperature. You can sort of conclude that dX change in CO2 means dY change in temperature, but even then that's only possible when you have a handle on the changes in all of the other forcings.
Furthermore, the temperature forcing due to livestock methane only exceeds the forcing due to CO2 produced by the transportation sector. It does not exceed that due to all sectors of the economy.
Yeah, tell me more about this "money machine" where climate scientists are getting rich instead of selling out to the oil companies as climate skeptics. For that matter, tell me more about the scientists who have lost their jobs due to their dissent on global warming. Climate skeptics get their papers published; they're not drummed out of their "cushy" government-funded university positions. They may get shredded in the followup literature, but that depends on the quality of their evidence. Tell me more about the climatologists who shut up and toe the party line despite their secret dissent. Names, please.
I'm amazed you have the gall to complain about the poor suppressed climate skeptics in light of the subject of this very article, not to mention the enormous corporate-funded climate skepticism machine.
To back up my point, I direct you to the junkscience.com link I posted. They have a full scientific breakdown that completely debunks the concept of human-based global warming. I can, in turn, direct you to any one of hundreds of actual published scientific papers which reach the opposite conclusion. I am curious why you prefer to base your opinions on a lawyer's website.
Science has yet to prove that human Greenhouse Gas (GG) emissions are released in quantities sufficient to affect anything more short term local climate. That is far from the case. The scientific literature you want to read on this subject is that concerning the estimation of a quantity called "climate sensitivity".
In fact, most of the evidence points to the exact opposite conclusion. For proof of this statement, I point you to the excellent book mentioned in the first link I posted. Singer and Avery have made a lot of very dubious claims (e.g., here).
Arctic Ice cores contain trapped gases and material unchanged from the time the ice formed. They provide an excellent snapshot of what the climate was like at various times in the past. Study of the ice cores provides very strong evidence that the Earth is traveling in a predictable and cyclic pattern through warm and cold periods, and the patterns shown in the ice cores can be very accurately mapped to historical weather patterns. The problem is that the paleoclimate evidence indicates that the Earth has been cooling for most of the time since the last ice age ended 10,000 years ago (here). They also show remarkable correlation between changes in CO2 level and temperature (here. I wouldn't attempt to use the paleoclimate record to support your point if I were you.
This, combined with the effects of the Solar maximum and minimum's effects on the Earth combine to form a near perfect picture of the weather in the past. Hardly. The fact is, we cannot we predict the Earth's climate far in the past by any of our paleoproxies, although in the last few hundred thousand years we do see the CO2/temperature correlations.
As a general discussion point, I would direct you to look up Mount Pinatubo. [...] Scientists at the time calculated that Pinatubo had spewed more GG's into the atmosphere than all of humanity had throughout it's entire history (a claim that has since been backed up by further study) That is completely and ridiculously false. The total CO2 increase rate actually dropped a bit after Pinatubo, whose greenhouse gas emissions were a tiny fraction of human emissions. You are probably thinking of aerosols, which did lead to some global cooling.
I was already familiar with the Wikipedia cite, what other papers did you refer to? Right after my Wikipedia link, I said "See in particular, Foukal et al. (2006) and Stott et al. (2003)." The full references:
P. Foukal, C. Fröhlich, H. Spruit, and T. M. L. Wigley, "Variations in solar luminosity and their effect on the Earth's climate", Nature443, 161 (2006) (link)
P. A. Stott, G. S. Jones, and J. F. B. Mitchell, "Do models underestimate the solar contribution to recent climate change?", Journal of Climate16, 4079 (2003) (link)
You say the CO2 emissions correlate with global temp curves, did they cause the Medieval Warming Period or Holocene?
No. I have not claimed that CO2 emissions are the only factor that influences global temperature, nor have I claimed that the Sun does not affect global temperature. What I claimed is that solar variations cannot account for the majority of the recent (last 50+ years) warming.
Other than solar activity, the only explanation for the extraordinary Holocene warming is a recent (1999) theory that the Earth's tilt may have changed for a couple thousand years. That theory is based on a model, there's no evidence as of yet. As soon as you try to translate "sunspot number" into "warming", that too is based on a model, and there's even less evidence of that than there is for orbital forcings, although there is some evidence that some localized coolings during the Holocene were due to reductions in insolation.
Possibly, except that the Earth's history shows the global climate has little sensitivity to CO2 levels. It is impossible to predict absolute global temperatures from absolute CO2 levels alone; you have to know what all the other forcings are doing; paleo data that far back doesn't tell you anything about the climate sensitivity. You can do better predicting changes in temperature from changes in CO2 levels, but even that is not very useful given the sparsity of the data on million-year timescales. Changes in CO2 levels and changes in temperatures do correlate well in the finer-grained data over the last few hundred thousand years (e.g. the Vostok ice cores). And CO2 is in fact implicated even in far-past climate changes, such as the Ordovician cool period you mention (see here).
Finally, there have only been three periods during which temps have been as low as they are today, and the other two took place during mass extinctions (Ordovician and Permian). Your point?
Also, the Permian extinction period is the only other time when CO2 levels have been as low. Again, your point? Are you trying to draw some relationship between CO2 levels and mass extinctions? If so, what?
Just another coincidence? Or proof that we're in an unstable period of cooling and the Earth's climate is eventually going to get warmer no matter what we do. The Earth's climate may get warmer "no matter what we do" on million year time scales, but the majority of the warming that has been happening recently is due mostly to us, and currently far outweighs much more gradual climate trends (which have been towards cooling, not warming, over the last 5000-8000 years).
Attributing global warming to "natural cycles" both disagrees with the nature of those cycles and ignores the existence of the greenhouse effect.
certainly there haven't been runaway greenhouse effects that the current models would lead us to expect What "runaway greenhouse effects" do you believe current models lead us to expect?
The IPPC reports are nevertheless reasonably good representations of the range of estimates found in the climatological literature. In fact, climatologists frequently use the IPCC projections in their studies. Read the other parts of the IPCC report that spend more time summarizing the science and, if you like, the papers they cite.
Slashdot Mirror
You need to pick better battles here. Arguing from a position of limitless ignorance is not a good strategy for you. We would need about 50 such platforms operating continuously for about 300-400 years to even start getting a feeling for CO2 recycling rates in the Atmosphere. Wow, more made-up numbers. 50 platforms. 300 years. Let's see that calculation. Considering that you apparently don't know anything at all about CO2 sink rates, this should be amusing. I also didn't say Pinatubo emitted CO2. I said a Volcanic eruptions LIKE pinatubo CAN emit BOTH gases. I was being generous; volcanic emissions of other greenhouse gases are even more insignificant than CO2. In fact, entire world total emission of all greenhouse gases from volcanism is insignificant compared to other sources.
On the other hand, the aerosols and aerosol precursors which produce cooling are significant, but as I said, they drop out quickly.
There is a reason why Pinatubo produced global cooling and not global warming, you know.
I can't speak for the mainstream media, but you can try looking at studies of regional warming, e.g. here. The scenario studied leads to an increase of 1-5C in the maximum summer temperatures, in different regions of the U.S. Of course, this is not actual "data", it is a model prediction. It's not immediately clear to me which global warming scenario they were using, however.
Ooops. Link.
Some control runs of GCMs on paleo data have been run just to see how they do, although their accuracy on such data is obviously going to be much worse than their accuracy for future prediction based on modern instrumental datat. Those runs indicate that GCMs can get mean trends decently well, but underestimate the decadal variability in temperatures. Which one retrodicts the Maunder minimum? Now you're being ridiculous. GCMs predict terrestrial climate, not solar physics. Solar physics is an input to GCMs, not an output. If you want to talk about the reliability of solar models, that is a completely separate issue. My point is that the past has examples of climate variation comparable to present climate variation. These past variations cannot reasonably be considered anthropogenic. The argument that the current variation must be anthropogenic because GCMs can be tuned to predict it from human inputs is weakened by the GCMs' inability to model these past variations. You are failing to distinguish between "the model predicts the wrong climate because it is inherently flawed", and "the model predicts the wrong climate because there isn't good data you can feed into it, so you get GIGO no matter how good the model is".
GCMs do hindcast well back to pre-industrial times. There is also the fact that you can't get GCMs to produce the observed warming without anthropogenic input under any kind of reasonable tuning. Anthropogenic forcings are a huge signal that you can't just explain away with a few minor tweaks here and there.
Um, science is full of predictions based on models. If you didn't have models, you couldn't make predictions at all. Models are not perfect, but they are based on known physics and do produce reasonable results in validation studies; GCMs do not "get the past wrong", unless you push them much farther than what they're being used to predict in the first place.
You can, however, predict that an increase in CO2 will produce an increase in temperature and vice versa, to a limited extent. (Too much change produces nonlinear feedbacks.) If you had even bothered to read what I provided for you, you would have seen that having a large polar land mass and a continent that stretches between the poles as we have today is an essential ingredient to ice ages. I am trying to imagine why you believe that is relevant to global warming, even if it were true. (Incidentally, there have been plenty of ice ages with the continents as they are now.) Or how it contradicts my statements (e.g., that a drop in CO2 can precipitate ice ages, and increases can end them). The only man-made activity that might change that is the Panama canal. Once again, what is your point? That manmade activity can't produce ice ages? (And no, the Panama canal will not change that.) You cannot possibly be suggesting that a computer scientist at the University of New South Wales knows more about the climate than a research professor and State Climatologist with a Ph.D. from the University of Wisconsin-Madison. Fine. Just ignore Hansen, Schmidt, and all the other rebuttals too. Whatever it takes to preserve your worldview. Put in random data, still get a hockey stick. So, your response is to ignore the flaws in their analysis and repeat your original claim. "I don't need facts! I know the truth!" That's some devastating logic there.
Note also that scientists have an even stronger incentive to publish correct results. Scientists are rewarded for proving each other wrong. If you fudge your study, people will point it out: they get far more immediate reward from doing so than a vague "well, this one paper might someday influence in some way my own climate funding".
This is not to mention the whole process of tenure, which provides immunity against getting fired for your conclusions, once you make it that far.
Finally, the sharpest scientists are the ones least susceptible to having their careers jeopardized under putative punishment for coming to the "wrong" conclusions: they are pretty much guaranteed funding no matter what they publish.
Right now, there is no plausible explanation for the current stat of our climate that does not include significant influences from human activities. Currently, there is little focus on producing other plausable explainations and existing inconsistencies (like the correlation between sunspot activity and global temperature) are not being explained in the Global Warming camp Global temperature is correlated with sunspot activity: the solar cycle has a detectable influence on the climate. It's detectable, and small. Well, not insignificantly small, but significantly smaller than anthropogenic influences. There are some good papers on this, starting with the 2006 Nature paper of Foukal et al., and also Stott et al.'s 2003 paper in J. Climate.
I don't know what is your basis for claiming that other explanations or inconsistencies are not being studied. Have you actually ever picked up a climate journal?
For every paper you can point to, I can point to another paper that contradicts your findings.
Go ahead, try.
We do not have the data to support human induced climate change.
We have more than enough data. We know how much human-induced CO2 there is, we know how much heat that retains, and there simply are not enough cooling effects in force to counteract it.
Remember Mount Penetubo in the early 1990's?
I was speaking of global warming, which is a century scale trend of increasing global temperature. Pinatubo caused a temporary cooling. Volcanoes do not contribute substantially to warming, except in scenarios like the snowball Earth where there isn't anything to take their emissions out of the atmosphere and they build up over millions of years. Over hundreds or even thousands of years, and with an active carbon cycle, they are irrelevant to warming.
By far vulcanism and solar intensity drive long term and short term climate variations.
They can drive both. However, the forcing due to solar variations over the last 150 years has been small compared to that of anthropogenic CO2, and the forcing due to vulcanism over that period of time is utterly negligible. Even over longer periods, solar variations have usually not been the main driver of climate; volcanism sometimes has been, at the ends of ice ages.
The only reason why it isn't undisputed yet is because we do not have the proper sensor gear in orbit around the earth to measure greenhouse gas sources in the oceans. That is a MAJOR gap in our understanding of how climate change works.
Greenhouse gas sources in the oceans are relevant to predicting climate change in the future, to estimate how much gas the oceans may source or sink. However, greenhouse gases in the oceans do not drive climate change; only gases in the atmosphere do. There are two questions here: is manmade CO2 driving global warming, and what will happen to the climate in the future. We have enough information to answer the first question in the affirmative, because it depends only on the historical atmospheric concentrations of CO2. Oceanic GHG concentrations are relevant to answering the second question. You cannot use uncertainty in oceanic GHGs to deny the fact that the global warming which has happened so far is primarily due to human influences.
The oceans cover 75% of the surface of the planet. We don't know Jack whats going on down there either.
That turns out to be incorrect; we know a great deal about what is "going on down there", including GHG concentrations. The uncertainty is about what will go on down there in the future.
So I think I am going to stick with Global warming can be blamed on oceanic vulcanism both for source gas emissions and also water temperature impacts
This can be disproven directly. As for source gas emissions, as I said before, GHG emissions from volcanos are measurable and are a tiny fraction of the increased GHGs that are in the atmosphere. Volcanic CO2, for instance, is emitted at a rate about 1-3% that of human emissions.
Even if it were impossible to estimate volcanic CO2 emissions (which it is not), we can measure directly how much total CO2 there is, and we can also measure directly how much of it is due to fossil fuel burning, and the latter is a huge contributor no matter how you choose to attribute all the natural sources.
As for ocean temperatures, that claim is even more ridiculous. Undersea volcanism cannot put out anything near the amount of heat necessary to produce global warming, and would also produce sea temperatures that are far higher relative to atmospheric temperatures than they actually are. Where did you get that idea, Iceagenow.com?
Your arguments only sound plausible as long as you ignore the actual numbers involved.
Just one volcanic eruption like Penetubo can in
There are tons of direct evidence to relate solar activity in deep time to climate change using ice core data....data which was collected before we got here.
Of course there is evidence of the influence of solar variation on the climate, but that evidence does not indicate that changes in the Sun's output have "far more" influence on the climate than man "ever will". The largest contributors to climate change have been things like orbital variations, changing greenhouse gas concentrations, changing albedo, etc.
I would also like to point out, that I do not think it is coincidence that the earth is warming during a time when scientists are describing some of the most intense flare ups of solar activity since indirect/direct measurement began of space weather in the past 80 years.
Recent variations in solar intensity are larger than they have been in the early 20th century, but what is important to the climate is not whether the variations are larger than usual, but how much greater the Sun's total intensity is than usual. The fluctuations, while larger compared to other fluctuations, are still very small changes in the total luminosity. If you work out how much change in temperature can be produced by that much change in insolation, it turns out not to be sufficient to explain the majority of global warming. (It can explain some, perhaps 15% to at most 30%, and probably closer to the former than the latter.) In fact, solar variations are worse at explaining the warming over the last 30 years than they are at explaining warming earlier in the 20th century. You can read about that in Foukal et al.'s 2006 Nature paper, or Stott et al.'s 2003 paper in J. Climate.
Point out just one study everyone agrees that man has changed the climate. You can't find one, in the scientific literature.
That statement is so absurd I don't know how to respond to it. You can only conclude that man has not changed the climate if you ignore everything we know about the climate.
All of the studies I have seen make extremely large assumptions about cause and effect,
On the contrary, they work directly off of observational data and known laws of physics. There are uncertainties in parameters, but they are not so large that we cannot attribute effects to causes.
and no one has been able to model these effects to produce the changes we see in the earths climate at the moment.
That's also false. Models do reproduce post-industrial climate change.
Like I said before, these so called "scientists" advocating climate change by man, can't even design a weather model that predicts or acccurate describes any future weather pattern we see on a daily basis without weather sat info.
I already pointed out at least two ways in which that statement is stupid: climate is not weather, and it makes no sense insist that scientists predict things without data such as satellites.
Which besides Solar activity I think there is plenty of evidence in the fossil record and today, to suggest volcanism is playing a role in the earths warming as well and is the second major factor in climate change.
On the contrary, we know that the total contribution of volcanoes — both land and oceanic — to the climate is not very significant, other than the occasional dumping of aerosols producing a temporary cooling. Volcanos produce almost no warming. Furthermore, we know that the vast majority of CO2 increase is due to fossil fuel burning: we can measure that directly from its isotopic signature.
Let me get this straight. You are claiming that predicting small weather patterns, or localized weather phenomina, has no correlation and is of no help in predicting large scale climate change?
Yes. The weather cannot be predicted farther than two weeks in advance, even in theory, due to limitations imposed by chaos. Thus, weather prediction
That's what I disagree with. CO2 levels and global temps have never tracked over 600 million years.
As I said, you cannot predict global temperature from CO2 level alone. Your statement would only be meaningful if all aspects of the climate other than CO2 were the same historically as they are now, but that is far from the case.
It is only in modern times that we have determined enough about the other natural forcings to be able to isolate the warming contribution of CO2 from other effects.
I agree that a 20X increase in CO2 isn't as big as it sound (I'm arguing that it has a minimal effect even at that level), but if a 30% increase is enough to raise temps up to 4.5 degrees C in a short time, according to the IPCC, why wouldn't a 20X increase increase temps by an equivalent amount?
First, the IPCC doesn't predict that a 30% increase in CO2 produces a 4.5 degree warming; that's the upper bound figure for more like a doubling in CO2.
A 20x increase in CO2 certainly would produce significantly more warming than a doubling, but as I said, CO2 is far from the only contributor to the climate.
The fact seems to support my argument more than yours, because, if it's logarithmic, maybe a 30% increase in CO2 is completely negligible and you have to get increases of 2000X (guessing again) or more to see a difference.
Making numbers up out of thin air does not support your point.
Logarithmic curves are a great magnitude equalizer; any kind of doubling produces the same amount of warming. So an increase from 1 to 2 ppm theoretically produces the same warming as an increase from 1000 to 2000 ppm.
(This sounds absurd, and to some extent it is, because the actual curve is not perfectly logarithmic, although it is logarithmic for concentrations around 100-1000 ppm. It flattens out at even higher concentrations because of all the extra feedbacks that start kicking in.)
What exactly do you doubt, here? Do you doubt that the amount of sunlight trapped by a given concentration of CO2 can be calculated accurately? That is actually one of the easiest things to calculate, and the amount of heat retained by the atmosphere is more than enough to explain the current warming. If you want to propose an alternative, you not only have to come up with a different mechanism for warming (solar variations doesn't work for reasons already explained), but you also have to come up with extra large cooling mechanisms too, to explain what is countering all the CO2. Claiming that CO2 just doesn't cause that much warming is not an escape; it follows very simple and laboratory-testable physics of radiation adsorption.
I think much of the increase in CO2 over the millennia is caused by the huge increase in lifeforms.
What increase? Over what period of time? You mean, the last 20,000 years (here)? What increase of lifeforms are you talking about here?
Incidentally, it is certain that the major increase of CO2 over the last 150 years is due to fossil fuel burning, since that leaves a unique isotopic signature that can be detected.
My understanding from discussing GW with others is that CO2 from volcanoes has little impact on the climate because it can't get high enough into the atmosphere to make changes.
Over the short term, that's true, but in the "snowball Earth" scenarios, it's the primary mechanism by which the Earth can melt: with so much ice, the oceans can't take up much CO2, and over millions of years enough accumulates to thaw the planet.
As for other aerosols, over a half billion years, don't you think we'd have several cases of CO2-driven warming?
We surely do; this is most visible over the last million years in the Vostok cores.
As I've mentioned before, that Appalachian Mountains theory flies in the fact of other theories that have pretty g
Regardless, it's still a specious argument. There are many things that have had more influence on the climate than humans have. But that doesn't mean that the climate change caused by humans is of negligible impact on on human societies. Unlike climate which has changed and will change long after we are gone, the number of species that are extinct and can be easily shown to be so through direct human action is far more convincing than climate change from scientists who cannot even forecast the weather properly even today without actually a camera in space looking at where it is going to rain tomorrow, let alone what cliamet will be in 10 -20 or even 30 years. That is, again, a specious argument; predicting the weather is a very different problem from predicting the climate. Furthermore, why do you bring up being unable to predict the weather without satellites and such? Of course you can't predict much if you have no data. But in the real world, we do have data.
You are also comparing apples and oranges; you point out observational evidence of species extinction, and then turn around and compare it to predictive power in the future. Of course prediction is harder than observation. Try comparing observational evidence of species extinction to observational evidence of man's past and present influence on the climate. Climate is really not the root cause. The earth has been MUCH warmer in the past, and much colder, without any people around so get over it. The fact that the Earth has been warmer and colder in the past has nothing to do with whether climate change is good for us as a species.
All that being said, I agree that biodiversity and other environmental issues are serious problems in themselves, and not ones that are being helped by global warming.
"I'm sorry, you cannot on the one hand claim that the climate is insensitive to changes in CO2, and then claim that CO2 doesn't impact the global climate."
I meant to say "does impact". IOW, yes, you are claiming that CO2 doesn't impact global temperatures.
Furthermore, the temperature forcing due to livestock methane only exceeds the forcing due to CO2 produced by the transportation sector. It does not exceed that due to all sectors of the economy.
Yeah, tell me more about this "money machine" where climate scientists are getting rich instead of selling out to the oil companies as climate skeptics. For that matter, tell me more about the scientists who have lost their jobs due to their dissent on global warming. Climate skeptics get their papers published; they're not drummed out of their "cushy" government-funded university positions. They may get shredded in the followup literature, but that depends on the quality of their evidence. Tell me more about the climatologists who shut up and toe the party line despite their secret dissent. Names, please.
I'm amazed you have the gall to complain about the poor suppressed climate skeptics in light of the subject of this very article, not to mention the enormous corporate-funded climate skepticism machine.
P. Foukal, C. Fröhlich, H. Spruit, and T. M. L. Wigley, "Variations in solar luminosity and their effect on the Earth's climate", Nature 443, 161 (2006) (link)
P. A. Stott, G. S. Jones, and J. F. B. Mitchell, "Do models underestimate the solar contribution to recent climate change?", Journal of Climate 16, 4079 (2003) (link) You say the CO2 emissions correlate with global temp curves, did they cause the Medieval Warming Period or Holocene?
No. I have not claimed that CO2 emissions are the only factor that influences global temperature, nor have I claimed that the Sun does not affect global temperature. What I claimed is that solar variations cannot account for the majority of the recent (last 50+ years) warming. Other than solar activity, the only explanation for the extraordinary Holocene warming is a recent (1999) theory that the Earth's tilt may have changed for a couple thousand years. That theory is based on a model, there's no evidence as of yet. As soon as you try to translate "sunspot number" into "warming", that too is based on a model, and there's even less evidence of that than there is for orbital forcings, although there is some evidence that some localized coolings during the Holocene were due to reductions in insolation. Possibly, except that the Earth's history shows the global climate has little sensitivity to CO2 levels. It is impossible to predict absolute global temperatures from absolute CO2 levels alone; you have to know what all the other forcings are doing; paleo data that far back doesn't tell you anything about the climate sensitivity. You can do better predicting changes in temperature from changes in CO2 levels, but even that is not very useful given the sparsity of the data on million-year timescales. Changes in CO2 levels and changes in temperatures do correlate well in the finer-grained data over the last few hundred thousand years (e.g. the Vostok ice cores). And CO2 is in fact implicated even in far-past climate changes, such as the Ordovician cool period you mention (see here). Finally, there have only been three periods during which temps have been as low as they are today, and the other two took place during mass extinctions (Ordovician and Permian). Your point? Also, the Permian extinction period is the only other time when CO2 levels have been as low. Again, your point? Are you trying to draw some relationship between CO2 levels and mass extinctions? If so, what?
Just another coincidence? Or proof that we're in an unstable period of cooling and the Earth's climate is eventually going to get warmer no matter what we do. The Earth's climate may get warmer "no matter what we do" on million year time scales, but the majority of the warming that has been happening recently is due mostly to us, and currently far outweighs much more gradual climate trends (which have been towards cooling, not warming, over the last 5000-8000 years).
Attributing global warming to "natural cycles" both disagrees with the nature of those cycles and ignores the existence of the greenhouse effect. certainly there haven't been runaway greenhouse effects that the current models would lead us to expect What "runaway greenhouse effects" do you believe current models lead us to expect?
The IPPC reports are nevertheless reasonably good representations of the range of estimates found in the climatological literature. In fact, climatologists frequently use the IPCC projections in their studies. Read the other parts of the IPCC report that spend more time summarizing the science and, if you like, the papers they cite.