Saturday, October 18, 2014

Climate: The Implication of Uncertainty

Anyone who looks seriously at climate issues should recognize that the consequences of climate change are very uncertain. My own view is that they are sufficiently uncertain to raise serious doubts about the sign as well as the size of the effect, that warming due to human production of greenhouse gases might well make us better off rather than worse off. Even if I am wrong and the effect is almost certainly negative, how negative it will be is very uncertain. CO2 emissions might fall sharply due to increases in the cost of fossil fuels or decreases in the cost of alternatives. For a given value of emissions, varying estimates of climate sensitivity imply at least a factor of two range for the resulting temperature. For a given increase in temperature, the effect on humans depends on what humans will be doing for the next century. Diking against a meter of sea level change could be a serious problem for Bangladesh if it happened tomorrow. If Bangladesh follows the pattern of China, where GDP per capita has increased twenty fold since Mao's death, by the time it happens they can pay the cost out of small change.

A possible response to this point is to argue that uncertainty is no argument against action. One simply replaces the uncertain range of outcomes with the best estimate one can provide of its expected value, the average of costs weighted by their probability, and acts as if that were the known consequence of warming. If the estimate of expected cost is ten trillion dollars, then any precaution to prevent it that costs less than ten trillion is worth taking.

It is a possible response and a popular one, but it is wrong for a reason that ought to be obvious to (at least) economists. The question we are answering is not "what should we do?" but "what should we do now?" Waiting may raise the cost of dealing with the problem but it will also provide additional information. The more information we have, the better our ability to decide what precautions are worth taking. Or not worth taking. Uncertainty that will be reduced over time is an argument against immediate action.

The usual rhetorical response is to claim that we barely have time to act at all, that if we wait more than a very short time it will be too late. This claim becomes less persuasive the more times it is made, and it has  been made, by various people, quite a large number of times over the past twenty years or so. It largely depends on picking some arbitrary temperature change, most commonly two degrees C, and treating it as if it were the end of the world. As salesmen commonly put it, "Buy Now—This Is Your Very Last Chance To Take Advantage of Our Special Offer."

For a more realistic opinion, consider an estimate of the cost of waiting by William Nordhaus, an economist who has specialized in climate issues. In the course of a piece arguing for immediate action against climate change, he reported his estimate of how much greater the cost of climate change would be if we waited fifty years to deal with it instead of taking the optimal action at once.  The number was $4.1 trillion. He took that as an argument for action, writing that "Wars have been started over smaller sums." 

As I pointed out in a post here responding to Nordhaus, the cost is spread over the entire world and a long period of time. Annualized, it comes to something under .1% of world GNP.
"Thought before action, if there is time."
(quote from a character in a Dick Francis novel)
And there usually is.


Anonymous said...

Here's an interesting quote:

“Lomborg’s attitude toward risk is also troubling. He focuses only on the middle range of the panel’s projections, dismissing the risk from the higher end of the range. But if the risk is great, then it may be worth acting against even if its probability is small…

The rationale for reducing emissions of carbon dioxide is to reduce the risk of the possibility of catastrophic outcomes. Making the transition to cleaner fuels has the added benefit of reducing the impact on public health and ecosystems and improving energy security — providing benefits even if the risk is eventually reduced…

There is no easy solution to this problem; the challenge is how best to develop options that are feasible, efficient, viable and scalable. Lomborg is correct to be concerned about the possibility of bad policy choices. But I have yet to see any option that is worse than ignoring the risk of global warming and doing nothing.”

Bonus points if you can name the author.

David Friedman said...

I'm guessing Mankiw.

Anonymous said...

Actually, Judy Curry.

MikeP said...

That might be an interesting quote if it was from some libertarian luminary or sometime ally of Lomborg's. But as a rebuttal by a climate scientist, it is plainly unsurprising.

And this statement...

But I have yet to see any option that is worse than ignoring the risk of global warming and doing nothing. unlikely to be true.

Just to cite one example, consider the Stern Review's absurd discount model. As Nordhaus's critique ably notes, seriously following the logic of that predicted future leads to ridiculous results. So, indeed, that option would be worse than ignoring the risk of global warming and doing nothing.

David Friedman said...

Nordhaus, at some point, had calculated that the cost of following out the Kyoto protocol was several times the benefit. Whether that's still his view I don't know.

Anonymous said...

One of the mistakes that some folks make is to assume that the uncertainty is one-sided towards inappreciable.

Curry has made it her mantra to play up uncertainty beyond that's reasonable; perhaps MikeP is unfamiliar with her change of heart since she wrote that comment. Since the science hasn't changed and has only become more certain, something else is motivating her.

MikeP said...

Annualized, it comes to something under .1% of world GNP.

Another way to put this is that, with a world GDP of $72 trillion, this is equivalent to someone who earns $72,000 a year (after tax) who has to worry about a possible unexpected $4100 expense -- some time in the next 50 years. $80 a year. $7 a month. But only if global warming proves harmful and if no changes occur in the next half century that thwart that harm.

What's the alternative?

With 35 billion tons of CO2 emission and a tax of $35, the annual global tax on CO2 is $1 trillion, rising as the emissions rise and rising as the predicted social cost of carbon rises. Our analogous $72,000 earner is being asked to spend $1000 a year -- and more than that year after year -- to insure against a loss of $4100 that may or may not occur over the next 50 years. Oh, and did I mention that this insurance is forcibly taken by a new government bureaucracy built just for the purpose?

Waiting the 50 years is pretty obviously the better course.

Anonymous said...

@MikeP, the sad irony is that those most responsible for manmade climate change will suffer least whereas those least responsible will suffer most. The issue isn't just one of economics, it's also basic accountability and fairness, two concepts that are often overlooked.

Dan Pangburn said...

There is no risk (it stopped warming before 2001), only benefit (increased plant growth) for increasing CO2.

A physics-based equation, with only two drivers (both natural) as independent variables, explains measured average global temperatures since before 1900 with 95% correlation, calculates credible values back to 1610, and predicts through 2037. The current trend is down.

Search “AGWunveiled” for the drivers, method, equation, data sources, history (hind cast to 1610), predictions (to 2037) and an explanation of why CO2 is NOT a driver.

MikeP said...


As near as I can tell, those who will suffer most are those whose path from poverty to prosperity can no longer be powered by inexpensive fuels.

Global warming alarmism is almost entirely driven by the rich of the world, who now have the wealth to satisfy luxuries like worrying about the climate a century hence.

Meanwhile, people from places that have actual concerns -- such as hundreds of thousands dying annually from poor sanitation, unsealed homes, and cooking over open wood fires -- aren't terribly supportive of efforts to tax carbon to curb climate change.

Anonymous said...

@MikeP, you're merely presenting a logical fallacy. Mitigating manmade climate change does not require forcing the world's poor to remain poor, nor does it require that other issues be left unaddressed.

Carbon-based energy is "inexpensive" only because the air, water, and land are treated as free sewers. Correct those very real negative externalities (again, markets are notably poor at dealing with those) and carbon-based energy isn't so cheap.

Unknown said...

GM: "you're merely presenting a logical fallacy. Mitigating manmade climate change does not require forcing the world's poor to remain poor, nor does it require that other issues be left unaddressed."

Unfortunately, it does. Just ask yourself: if it were shown that fears of climate change are actually mistaken, so there is no reason to reduce CO2 emissions, would that make it easier or harder for the world's poor to get richer? I think the answer is obvious. Indeed, I think it's quite obvious that the cost to the world's poor of drastically reducing CO2 emissions would be very substantial, and would result in millions of deaths compared to the situation where CO2 is not reduced and it turns out that climiate change is not a problem. If you think reducing CO2 would prevent even more deaths than it causes, then your position makes sense, but don't delude yourself into thinking it is a free lunch. It's very obviously not.

GM: "Carbon-based energy is "inexpensive" only because the air, water, and land are treated as free sewers."

If you're referring to pollution other than CO2 emissions, then of course that's a problem that would best be addressed by measures other than a carbon tax. It seems very unlikely to me that properly pricing in these other externalities would make all fossil fuels uneconomic, which is what would be needed for your argument that reducing CO2 doesn't cost anything to be valid.

I suspect that your real argument is that if everyone adopted every aspect of your ideology, then not only would CO2 be reduced, but the poor would also be helped much more than at present, because of aspects of your ideology completely unrelated to CO2 reduction. I think this argument is rather detached from reality, in several respects.

David Croson said...

I gave a talk in Helsinki a few years ago about Grand Challenges for European Science (with an emphasis on Nordic Countries).

It isn't on the slides, but I built up the carry-an-umbrella example [done out in mind-numbing detail, for the non-decision-scientist audience] to be directly analogous to climate-change research (to get better information about the correct actions.)

Mac Muir said...

The additional CO2 is not causing any significant warming of the planet(The physics is clear - See my previous comment to this site). What it is doing is fertilizing plants.

If you are serious about major reductions in CO2 emissions The only real options are nuclear but the "greens" are largely blocking that.

It is possible that we may see fusion coming on line within ten years either from what Lockheed Martin is doing, Bussard's polywell, Hirshes Electrostatic mirror or some variant of the above. Whatever it is it is likely that the Department of Energy will continue their tradition and not be funding it.

The "green" solutions of wind and solar are expensive per KWHr and are not 24/7 power. We do not have today any way to store the large amounts of power that would be needed to make either wind or solar viable solutions (the closest is pumped hydroelectric storage but it is far from a viable solution). Likewise wind turbines kill birds and bats.
Solar panels may be nonpolluting to use but they are very polluting to make.

jimbino said...

Carbon taxes and other expensive measures to combat speculative climate change are an affront to the childfree adult.

He has already done his part in reducing pressure on the planet, including climate change, resource depletion and threats to plants and animals, by simply not breeding.

No good act ever goes unpunished by the gummint, of course, and the childfree person is taxed, through Obamacare, to finance the breeding by others that costs some $30,000 per live birth, and then, through property taxes, to support the mis-education of the little future polluter.

Then, to add insult and injury to those already severe injuries, all the cost and effort will show little benefit for the childfree adult, who will be dead in a few decades--most all of the rewards, if any, will benefit the polluting progeny of the breeders!

I say: tax every breeding event now and use that tax to finance solutions to the "climate change" problem.

Daublin said...

GM, I note you do not respond to what MikeP actually wrote, and again just put forward a position out of the blue.

MikeP, it is clearly true what you say about the impact of CO2 controls. Being denied the use of an inexpensive vehicle is devastating if you are trying to hold down a low-paying job.

It's less certain, but I suspect you are on to something about the motivations of people who push for CO2 controls. It's a way of saying, in polite company, that you are rich enough not to care about such trivia as $10k here, $10k there.

Anonymous said...

I think it's quite obvious that the cost to the world's poor of drastically reducing CO2 emissions would be very substantial, and would result in millions of deaths

That's a strawman.

Dan Pangburn said...

GM - You have been hoodwinked by people whose true agenda has nothing to do with climate. Or, perhaps you are one of them.

CO2 change (human activity) does not, never has and never will have any significant effect on climate. The fact that 'climate science' did not predict and has not been able to rationally explain the flat average global temperature trend since before 2001 is a clue.

The analysis at which explains the up trends and down trends of average global temperature with 95% correlation since before 1900 irrespective of whether the influence of CO2 was included or not is another clue.

MikeP said...


First, I didn't say that. Second, I wouldn't say it since I don't think it's quite obvious. But, third, it is not a strawman since it is not trying to state anyone's position: it's simply stating a possible outcome of following one line of policy.

I happen to agree that drastically reducing CO2 emissions will have a resoundingly negative effect on the world's poor: I just don't think that it is quite obvious.

In particular, that conclusion requires recognizing that premature death rates plummet in individual nations as each industrializes. Hence making it more difficult for them to industrialize -- either by giving the keys of modern energy to the rich governments of the world in the worst case to delaying industrialization for a few years due to pricier energy source in the best case -- will result in millions of deaths that would not have otherwise occurred. Compared to those, the predictions by the IPCC of premature deaths in high CO2 emission scenarios are miniscule.

Anonymous said...

In the following linked article recently published in Scientific American, the authors argue that uncertainty is a reason to take action on climate change:

Anonymous said...

@MikeP, apologies for misattributing the quote.

David Friedman said...


Did you find the article you linked to convincing? I hope you noticed that it entirely missed the point I made in my post—that uncertainty which will be resolved over time is a reason for delay.

You might also have noticed:

"However, although sea levels are most likely to rise by about 1m, we’re really looking at a range between 0.3m and 1.7m. Therefore, flood defences must be at least 1.7m higher than today – 70cm higher than they could be in the absence of uncertainty."

They are presumably talking about sea level rise by 2100, although 1.7m is well above the upper range of the IPCC projection. Their argument assumes that the town must decide today how high it must build dikes to deal with floods almost a hundred years from now, which is crazy. Between now and 2100 there will be plenty of time to adjust the height of dikes to take account of sea level rise as actually observed.

Anonymous said...

@Dan Pangburn, if manmade climate change consisted solely of surface temperature change, your entire oeuvre might have value.

Your curve-fitting exercises cannot "explain" any of the other observations of manmade climate change, so, as a supposed "debunking" of theory, they are not.

Additionally, we know the CO2 and the other trace GHGs are the reason the global average surface temperature of the planet is above the freezing point of water - remove those trace gasses and the planet starts to freeze solid. We also know that our burning of carbon-based fuels has raised the concentration of CO2 about 40% above its level of the past 800,000+ years.

Dan Pangburn said...

GM - Your lack of science skill has made you gullible to mob-think.

Curve fitting does not hind cast or forecast.

Hind cast to 1610 is shown in Figure 3 in the paper at

The equation allows prediction of temperature trends using data up to any date. The predicted temperature anomaly trend in 2013 calculated using data to 1990 and actual sunspot numbers through 2013 is within 0.012 K of the trend calculated using data through 2013.

The predictions depend on sunspot predictions which are not available past 2020. The predictions to 2037 for two assumptions of SS numbers are graphed in Figure 1 of the "AGWunveiled" paper.

The 'consensus' got it wrong when they decided to blame CO2 change for global warming. As shown in Table 1, there is no significant difference in accuracy whether the influence of CO2 is included or not. Thermalization and the 70,000 or so more EMR absorption opportunities of water vapor compared to CO2, as explained in the paper are why CO2 change has no significant effect on average global temperature. With no effect on temperature, there can be no effect on climate.

Anonymous said...

@Dan, I wish you had read the two major points I made in my comment.

You can insist that CO2 has no relevance to the climate system, but that's just plain wrong.

And no, anthropogenic CO2 isn't magically different than non-anthropogenic CO2.

Dan Pangburn said...

GM - I read your "... two major points...". They are both wrong.

I did the analysis myself at All the necessary information is provided so anyone competent with a spread sheet can check it. Actually, you can check it from the just the graphs. Spot check the graphs if you don't trust them.

I'm not insisting on anything. The analysis demonstrates that CO2 change has no significant effect on climate. I have made the analysis available to the public. If there is an error in the analysis, point it out. Opinions are worthless.

If you had looked at the analysis you might know that it makes no difference what causes the CO2 change.

Anonymous said...

Perhaps in the decades to come, dikes could be developed that are somehow adjustable, either upwards or downwards. For all I know maybe someone has already designed such adjustable dikes.

MikeP said...


Indeed, I immediately noticed as David Friedman did that dikes played a prominent example in that unconvincing uncertainty article. Oh noes! People might have to spend perhaps 10% more on a dike some decades from now so they could optionally make the dike taller some decades after that!

Then again, it is only five-century old technology. Solving the problem of later making dikes taller might need government research money.

Anonymous said...

@Dan, if CO2 concentration changed from the current 400ppm to 0ppm, would that have no effect on the climate?

You're missing out on all the other observations - stratospheric cooling, ocean acidification, loss of Arctic sea ice, loss of land ice, ecosystem changes, etc., etc. that are part of manmade climate change.

It's trivial to replicate the global average surface temperature record by weighting various factors - the question is whether they're relevant or physical. One could probably use Excel and a time series of the DJIA, median age of Germans males, and the average length of the hems of women's skirts, and, weighting appropriately with various scale factors and a polynomial equation and come up with the time series of GAST. Doesn't mean those things are related.

jimbino said...

I heard a "climate scientist" today on Minnesota Public Radio who warned of the threat of ocean-level rise caused by melting of the Antarctic ice shelves.

As pointed out in the Wikipedia article on ice shelves, elementary physics declares that melting of an ice-cube in a topped-up glass of water will neither raise nor lower the water level.

The Wikipedia article mentions that ocean-level may still rise somewhat owing to the slightly greater densities of glacial ice and salt water, and that, if all the world's ice shelves were to melt away, the oceans would rise some 4 cm. This would be a one-time event, of course, so should we worry about ice-shelf melting at all, especially as it might facilitate mining and oil or gas production?

Anonymous said...

@jimbino Read this:

Dan Pangburn said...

GM – If the CO2 level dropped below about 150 ppmv all life on earth would end so there would be no one to care. Because the EMR absorption opportunities for water vapor outnumber those for CO2 by 70,000 to 1 the change to climate would probably be undetectable anyway.

Everything has been considered. The coefficient of determination, R^2, is a measure of how much of the measured data is explained by the equation. R^2 = 0.9049 means that the equation explains 90.49% of measurements. Everything not explicitly considered (such as the 0.09 K s.d. random uncertainty in reported annual measured temperature anomalies, aerosols, CO2, other non-condensing ghg, volcanoes, ice change, etc.) must find room in the unexplained 9.51%.

I haven’t tried to incorporate the influence of any of those things you listed, but I expect that some of them might do better than CO2 change which only raised R^2 from 0.9049 to the insignificantly higher value of 0.9061.

Apparently either you have not looked at the equation or lack the science skill to understand it. There are only 2 independent variables; the time-integral of sunspot number anomalies and an approximation of the net effect of all natural ocean cycles. It is not a polynomial. It is an equation resulting from application of the first law of thermodynamics.

You can still look at the graphs. They show the results of the equation superimposed on measured average global temperatures.

Anonymous said...

@Dan, you're outside the realm of science and are merely playing games with numbers.

If the CO2 and the other trace GHG gases are removed from the atmosphere, all other constituents unchanged, the surface temperature starts to decline until all the H2O condenses out, then the liquid water on the surface freezes, and eventually the oceans freeze solid.

That's not "undetectable".

Those other things I mentioned aren't factors affecting temperatures, they are observed changes in the climate system because of the energy imbalance created by the 40% increase in CO2 we've created in the atmosphere.

Sunspots don't change ocean chemistry; additional CO2 in the atmosphere certainly does.

Since the standard theory explains more observations better than your mathematical games, your theory that CO2 has nothing to do with the climate system's energy balance is rejected.

jimbino said...


Thanks for the ice-shelf reference, but it did not give me an idea of how much the oceans would rise if the Antarctic ice shelves melted away, let alone the rise if all the glaciers and ice shelves melted away at once.

jimbino said...
This comment has been removed by the author.
Mac Muir said...

Can we go back to the physics here. Any greenhouse gas acts as a set of narrow band reject filters taking out part of the far infrared. Water takes out thousands or tens of thousands. CO2 takes out 3. The three that CO2 takes out are taken out completely so additional CO2 does not change anything.

Carbon dioxide is not causing warming. Here is why I say that:

Bodies radiate energy in the form of electromagnetic waves. The spectrum of this energy is determined by the temperature of the radiating surface. The surface of the Sun is at a temperature such that most of its radiation is in the frequency band we call visible light with some in the near infrared (which we sense as radiant heat) and some in the ultraviolet. Most of the UV is blocked high in the atmosphere. The visible (0.4-0.8 micron) and near infrared (0.75-1.4 micron) largely makes it to the earth’s surface.

The Earth having a much lower surface temperature will radiate energy back into space in the far infrared wavelengths (1-30 microns. Peaking around 10 microns. Most of the energy is in the 9-13 micron range.). Carbon dioxide and the other so called “greenhouse gasses” tend to absorb and re-radiate radiation in the far infrared and thus trap heat on the Earth.

Each vibrational mode of a particular type of molecule will act as a narrow band reject filter taking out one particular wavelength. This is based in quantum physics. The energy of a photon is inversely proportional to wavelength and only photons with the correct energy are absorbed. For CO2 these are 2.7, 4.3 and 15 microns. Two are base vibrations one is an overtone.

For an explanation of this see:

Note: Water as vapor, liquid and as ice has a very complex series of overtones and effects much of the far infrared.

Scientists like to assume things are linear, even when they are not. It makes modeling much easier. I suspect that many scientists involved in this modeling just assumed that the energy absorption was linear without checking.

I tried to research this. Starting in 2001. I Googled every form of the question I could think of for years without result. Finally I found the answer on my own bookshelf. The fifth edition of “Reference Data for Radio Engineers” (H.W. Sams & co. 1968) has a graph on page 26-28 showing the transmission of 300 meters (about 1000 feet) of air in the far infrared. The transmission of all three wavelengths affected by CO2 are already zero. The atmosphere is far thicker than 300 meters. Therefore it is safe to assume that almost no radiation at the wavelengths affected by CO2 was making it into space when the data for this graph was taken.

These three wavelengths are slivers of the entire far infrared. The skirts of the filters are sharp and thus constitute slivers of slivers.

This says that CO2 has already done virtually all the warming it can.

Case closed.

Mac Muir said...

This brings up a second point. If the planet is being warmed by ANY greenhouse effect then the Troposphere (lower atmosphere) should be warming faster than the surface. Years of balloon and later satellite data do not show this. [This claim is widely made but I do not have hard data to reference.]

Likewise I should point out that the chart I referenced represents an upper bound on the distance to opaqueness. 300 meters is fully opaque but shorter distances may be also. I remember reading someplace that one of the CO2 absorbing wavelengths is opaque in 30 feet but I cannot point to that data and 300 meters is adequate to my case.

A second point: The modelers like to assume that the weak warming caused by CO2 is amplified by water in the atmosphere. This assumes a positive feedback with a loop gain near one.

As far as I can tell the modelers are making this as an assumption rather than basing it on data. The actions of water in the atmosphere is quite complex, complete with numerous non linear effects (cloud formation, precipitation etc.). I propose a simple observation to indicate the sign of this feedback. Is the day to night temperature swing larger or smaller with high humidity or with low humidity. This is quite unequivocal: Temperature swings are smaller with higher humidity and therefore the net feedback is negative and therefore water in the atmosphere is attenuating not amplifying other greenhouse gas effects.

Positive externalities.

Extra CO2 does have a major benefit. It fertilizes plants. The two most important plant nutrients are CO2 and water. The process of photosynthesis takes six CO2 molecules and six water molecules in the presence of chlorophyl and light and converts them into a glucose molecule and six molecules of oxygen. The plant then converts the glucose into other needed molecules.

Most of the photosynthesis takes place in the pores in the leaves. The inside of the pore is wet. On average about one hundred water molecules leave for every CO2 molecule entering. With higher CO2 concentrations plants tend to constrict the opening somewhat so less water is lost while the plant is still getting more CO2.

It was predicted in the 1970's and 1980's that we would see mass starvation in the 1990's. this did not happen. Part of the reason why is the fertilizing effect of the extra CO2.

Anonymous said...

"I suspect that many scientists involved in this modeling just assumed that the energy absorption was linear without checking."


Anonymous said...

@jimbino If all ice melted, sea level would rise about 80 meters (260 feet, give or take).

Dan Pangburn said...

Mac – GM obviously lacks broad science skill, has been misled by unscrupulous warmers, and is apparently deaf to valid science-based discussion.

Missing from most discussions is thermalization of EMR energy. When a molecule absorbs a photon of EMR energy and conducts the energy to other molecules before it emits a photon, the absorbed EMR energy has been thermalized. If no time passed between absorbing and emitting, there would be no way to tell that it occurred and there would be no ‘greenhouse effect’.

Calculations show that the interval between absorption and emission is very short, 10 microseconds. However, the time for conduction to take place, which is the time between impacts of gas molecules, is much shorter, about 0.0001 microseconds at sea level conditions. Thus it takes about 100,000 times longer to emit an absorbed photon than to thermalize the absorbed energy. Obviously absorbed terrestrial EMR energy is thermalized. References to the calculations are included in the Science explains… section of

Consider this with respect to your Radio engineer’s reference. If the absorbed photons were emitted, the flux would not decline. Instead it goes to zero in 300 meters. The energy has to go someplace. It is conducted to other molecules. It is thermalized.
Thermalized energy carries no identity of the molecule which absorbed it. In the terrestrial radiation spectrum, nearly all 5-50 microns, water vapor is about 15,000 ppmv with 465 absorption lines while the 100 ppmv CO2 increase has only 1. Since the increase in absorption opportunities of a 100 ppmv increase in CO2 is only about 1 in 70,000, the effect of this increase in CO2 is insignificant. The process that eventually results in the energy being radiated from the planet is described in Science explains…

Anonymous said...

@Dan, if you left out the ad hominem, your arguments (such as they are) would improve.

Your mathturbation doesn't explain anything, it just correlated with global average surface temperature.

That's not how science works.

What's the physical connection between "sunspot anomaly" and ocean acidification?

Bravin Neff said...

David Friedman said:

"Anyone who looks seriously at climate issues should recognize that the consequences of climate change are very uncertain. My own view is that they are sufficiently uncertain to raise serious doubts about the sign as well as the size of the effect, that warming due to human production of greenhouse gases might well make us better off rather than worse off."

What immediately follows is your caveat. Ignoring it for the moment, it is hard for me to take seriously this view in light of the claim that climate change does not consist just in an average increase in temperature, but an increase in variability (my gloss of the subject finds claims of increases in 3 sigma and even 5 sigma events).

If that is correct, the implication is that extremes of all kinds will become more common. If human settlements were formed on the basis of climates with a narrower range of extremes, I can't think of an argument one can make other than such a future scenario implies a net cost. I'd love to be wrong.

Anonymous said...

@Bravin, exactly.

David Friedman said...

Bravin: Can you explain the reason to expect an increase in variability due to GHG warming? Evidence for it?

Looking at public statements, I see the claim of more extremes, but it seems to be specifically more extreme highs and more extreme rain (due to more water vapor at higher temperature). Both of those look like changes in the mean not in the variance.

As best I can tell, both the claim of more droughts and of more or more severe hurricanes have at this point been abandoned by the serious people, including the IPCC, although they are still visible in the public discussion. More extreme cold seems to be not a prediction but an argument invented after the fact when there was a very cold winter in the U.S.

Bravin Neff said...

"Bravin: Can you explain the reason to expect an increase in variability due to GHG warming? Evidence for it?"

Not very well, and I am not saying I am convinced of this point other than to say I have seen a variety of arguments that are plausible. Here's one:

Brian said...

"Bravin: Can you explain the reason to expect an increase in variability due to GHG warming? Evidence for it?"


It's essentially impossible for variability to increase under global warming. The reason is that, as in any thermodynamic system, all weather variability is driven by DIFFERENCES in temperature and not temperature itself. But under the standard global warming regime, all temperature differences are reduced. The troposphere warms more than the surface, so vertical differences are reduced. The poles warm faster than the equator, so latitudinal differences are reduced. Nighttime temperatures warm faster than the daytime, so short-term temporal variation is reduced. Winter temperatures warm faster than summer temperatures, so annual variation is reduced.

As you already mentioned, the only items that can increase are the temperature itself and precipitation. Everything else will have less variation.

Mac Muir said...

Conjectures as to how we got here.

Climate science was, for a long time, a scientific backwater (Not many people were studying it, not much funding, very limited access to supercomputers, etc.).

It was noted that man was adding vast amounts of CO2 to the atmosphere and several scientists wrote papers about possible effects. Shortly after this the coal miners in Britain went on strike and Margaret Thatcher used a “Global Warming” argument against them. This gave the GW idea wide publicity.

The concern in the 1970's was global cooling, the possibility that we were entering a new ice age. I am not sure just when this turned around. There was apparently a sharp temperature rise in 1979 ( Which happens to correspond to the repainting of temperature sensor enclosures in the US.)

In any event there were many unanswered questions and many scientists and others were concerned that we were “betting the planet” by continuing to burn fossil fuels with abandon. When faced with large uncertainties scientists and engineers tend to ask: “How bad could it be?” A number of ‘worst case’ analyses ensued and some of these analyses were pretty grim. At the same time just how realistic these ‘guesses’ were was an open question.

The news media started to pay attention but only to the more extreme alarmists since that was a ‘story’ while another equally competent scientist who said nothing was wrong was not a story at all.

Politicians and others started to pay attention and government money poured into research. Lots of people entered the field. Lots of graduate students, lots of new PhDs looking at the questions. But there was a trap here, the funding would only continue if there was a problem. Thus it was easy keep the funding going by writing papers playing up the worst case side of the continuing uncertainties and downplaying or ignoring the evidence pointing to the idea that just maybe there wasn’t a problem here at all. Many (most) of these papers would be full of qualifiers (might be, maybe, etc.) which would be ignored by the political types.

With the giant infusions of money it became possible to get lots of time on various supercomputers and the computer modelers were off and running. What is interesting is that they tend to call their results “Scenarios” not “predictions.” The political types tend to treat them as hard and fast predictions.

Another problem occurred in that the primary weather data was tightly held by only a few sites (Noaa and NASA Goddard in the US and the University of East Anglia (CRU) in England), There is evidence that these data bases have been “corrected” in ways that distort the data while much of the raw data has been conveniently “lost.” .

There are always those who see a way to ‘make a buck’ out of any situation and this was no exception. We have massive subsidies for wind turbines, ethanol, solar power, etc. as well as various carbon cap trading schemes. The ‘crony capitalists’ have been busy. Those receiving these subsidies tend to give large political donations. Al Gore has made a fortune.

One needs to feel sorry for those scientists who in good faith chose career paths based on the reality of AGW. They face an interesting set of ethical challenges

Anonymous said...

@Mac Muir Your conjectures are purest baloney.

If you want to know the background of the development of the scientific theory that humans are affecting the climate system, please read Spencer Weart's excellent "The Discovery of Global Warming".

It's at

Doing so will correct Mac's nonsense.

Dan Pangburn said...

Mac - You are spot on. I would add that the IPCC agenda has little to do with climate and instead is about taking from prosperous countries and giving to less prosperous ones. (The IPCC is dominated by representatives from less prosperous countries)

GM - More than 30,000 engineers and scientists say you are wrong at

And 9,000 PhDs say you are wrong at

Besides that, Since 2001 the CO2 level has increased by 30% of the increase 1800-2001 while the temperature trend (average of the 5 reporting agencies) has not increased.

Anonymous said...

@Dan, you've a long history of manmade climate change pseudo-skepticism. No fact will change your mind.

I can't argue with someone whose opinions are not based on facts, and who cannot answer the most basic questions that amply illustrate the fatally flawed foundations of his beliefs.

David Friedman said...

GM: So why not argue with me instead?

What good reasons can you offer to expect warming of two or three degrees C to produce large net negative effects?

Anonymous said...

@David - You're asking a sociological and political question that involves values, not a scientific question. "Large net negative" is a moral judgement.

I don't doubt there are people who would consider a mass loss of the human population because of manmade climate change a good thing. They wouldn't view that as a negative at all.

My personal take is that we are altering the climate system on a global scale and that doing so has impacts throughout the biosphere with which are interconnected and interdependent. We have no backup planet, and, the time evolution of such things as ocean overturning and ice sheet changes means that we're committed to what we've done and are doing for millennia to come.

Mac Muir said...

GM might want to consider that the Medieval Warm Period and the Roman period were both several degrees warmer than the present and were very prosperous times in Europe and in the MVP case also in China (I have no data about China in the Roman period so I will not make any claims about that).

Likewise the additional CO2 is having a significant positive effect on plant growth. It turns out that with rising CO2 plants grow faster, use less water and are more resistant to plant diseases. The AGW crowd consistently ignores this. I ask Why?

Mac Muir said...

Correction to last post:

Anonymous said...

@Mac - "several degrees"? No. Neither the MCA nor earlier "warm" periods were global or synchronous, as manmade climate change is now.

"Plants" is a very much larger subset of "plants useful to human beings"; if weeds grow as well or better than the plants we utilize, that's neither a net benefit nor a win. Besides, CO2 isn't the limiting factor in plant growth - many other factors are more important.

Anonymous said...

So when can we expect the IPCC Moral Philosophy Working Group to come out with its assessment?

Anonymous said...

@Paul, that's not the IPCC's job.

If you would prefer to make decisions uninformed by the best state of the science, you're welcome to do so. I wouldn't advise it.

Look at it this way - if a medical doctor advises that you quit smoking to avoid serious risks to your health, is that a moral judgement?

Brian said...

GM, you said "'Large net negative' is a moral judgement."

It doesn't have to be. It depends on what effect you're talking about. If the effect relates to economic growth, for example, large net negative is well defined and the proper object of scientific inquiry. Indeed, in the literal sense, any quantifiable effect that moves left on a number line is a net negative.

So why don't you answer David's challenge and provide evidence that several degrees of warming is likely to cause a net negative effect?

Anonymous said...

Making and justifying the value judgments has got to be someone's job-- and when some says "we've got to do this", as GM has repeatedly done upthread, most of us are likely to interpret that as volunteering for the job.

David Friedman said...

GM: I think if you read the IPCC report, in particular the summary for policy makers, it's hard not to see it as making value judgements and recommending responses.

I usually use "net negative"in the conventional economic sense, which sums consequences over everyone affected, measuring costs and benefits by what each person would pay to get or avoid the effect. It's not a perfect definition—you can find discussions of its problems and why it nonetheless makes sense to use it in several of my books.

Your response seems to assume that climate stasis is an option. On the geological evidence, it isn't. With or without our intervention, climate changes, although it's arguable that the change we create is faster than natural change usually is.

Most discussions take it for granted that change is bad—a very conservative assumption. I have yet to see any good reason to think that is true. I've discussed my reasons in past posts, especially:

Getting most of the world to switch from less expensive sources of power to more expensive ones is a large cost, and it doesn't make sense to do it unless you have some good reason to believe it brings a benefit, which requires some reason to think that warming is likely to have substantial net negative effects.

Mac Muir said...

GM: There is a great deal of data regarding the effects of additional CO2 on the plants that we use. Your comment about weeds was just silly.
Likewise many commercial nurseries add extra CO2 to their greenhouses to foster plant growth.

There is recent research indicating the the MWP was indeed global.

The science is solid: CO2 is not driving global warming.

I will repeat a thought from an earlier comment: One needs to feel sorry for those scientists who in good faith chose career paths based on the reality of AGW. They face an interesting set of ethical challenges.

Anonymous said...

Folks, the decisions to be made about what to do with regards to manmade climate change are societal ones, preferably informed by the science, but not made by the scientists themselves. And yes, doing nothing is a decision.

Climate 'stasis' is a strawman, in that what we need isn't an unchanging climate; what we need is a climate system within which our means of food production, the places we live, the ecosystems with which we are interdependent, can exist so that our very large and growing population can be sustained. We aren't a tiny band of hunter-gatherers riding out an Ice Age any more.

@David, I'm disappointed that you're back to the "less expensive" sources of energy claim. We know that the cost of the use of carbon-based energy is too low because negative externalities aren't accounted for in its price. My preference is that we correct that and then let markets dictate how we get and use our energy.

David (not Friedman) said...

GM- Hard to argue with that nice statement of what we need. But you still sound like you believe that any climate change would put us in a worse position to achieve it than we are in now. Do you believe that? If so, why?

Anonymous said...

@David (not Friedman) Our civilization has enjoyed a very favorably stable climate system for its entire existence. We are now altering the climate system outside that regime. Whether or not 7+ billion of us (and climbing, with all the needs we have and the infrastructure we have built on the assumption that the climate will remain as stable as we've come to expect) will continue in our numbers and our accustomed lifestyles is the big question. That's aside from the impacts on the remainder of the biosphere, upon which we are entirely dependent.

Consider ocean acidification for starters.

Mac Muir said...

GM: Many negative externalities have been claimed for additional CO2. To my knowledge none of them have actually been demonstrated. If any have: What are they?

I know you are stuck on warming which a previous comment of mine disproves. Mine is one nail of many in that coffin.

The preponderance of real science today seems to support the skeptics case.

I would be interested in hearing your scientific explanation of how additional CO2 causes warming and why that is on net detrimental.

Anonymous said...

@Mac, you clearly didn't read

Please do so.

Anonymous said...

@Mac, to correct your history of climate science, please read Guy Callendar's 1938 paper, "The artificial production of carbon dioxide and its influence on temperature", at

The idea that our adding CO2 to the atmosphere is warming the planet isn't something that was dreamed up recently.

Anonymous said...

GM: When you say "We know that the cost of the use of carbon-based energy is too low because negative externalities aren't accounted for in its price", are you defining externalities the way economists do? If so, why not answer Friedman's question about why you believe them to be significant and negative? Or, if the reason you gave then for not answering the question still holds and assessing the net externalities depends on a societal value judgment, then "we" evidently do not know that they net out to be negative; our political choices so far seem to imply that they're zero at worst.

David (not Friedman) said...

Ah, OK. We're discussing a temperature change of two or three degrees, yes? So your contention is that this is a larger change than we have ever experienced before? Interesting.
Suppose, for the sake of argument, that astronomers discovered that the solar system was moving into a dust cloud that would dim the sun enough to reduce Earth's temperatures by two or three degrees for the next 300 years. Would you then be happy about greenhouse gases?

Anonymous said...

@Paul - that we lack the political leadership and societal acceptance of the science says much more about the failure of our politicians and our society than it does the science.

Remember how action on smoking was delayed because the science was denied, attacked, obfuscated and so on despite the evidence in front of our faces?

There are many factors that go into the societal acceptance of a fact of nature, not all of which are based on reality and which can be influenced by the short-term narrow selfish goals of a few who view reality as a threat to their interests, monetary, ideological, and otherwise.

Anonymous said...

@David (not Friedman) - manmade climate change is much more than just warming surface temperatures.

We can all engage in what-if games, but those are just fiction. Let's stick to what we know.

Mac Muir said...

GM: Two little problems with your article. It says a doubling of CO2 will result in a 1 degree rise. No explanation as to why. No basis for the claim.

The straightforward application of the Beer-Lambert law might (or might not) lead to such a conclusion. This however assumes that CO2 is still in the linear region when it is actually in a saturation region. Keep in mind that much infrared spectroscopy is done over distances of inches or less.At those distances CO2 would be linear.

I suspect (But I have not done the math) that doubling CO2 from recent levels will cause a rising of 0.001 to 0.01 degree. (i.e. noise.)

The second point. If ANY greenhouse gas is causing the warming then the lower atmosphere MUST heat faster than the surface. Years of balloon and later satellite data do not show this.

I repeat my challenge:
I would be interested in hearing YOUR scientific explanation of how additional CO2 causes warming and why that is on net detrimental. By this i mean an explanation in your own words, getting into the basic science, not just pointing me at some web site.

Anonymous said...

@Mac I'm not going to debate anyone without a solid understanding of the basics of the science. You clearly do not have such an understanding.

If you don't want to go to the literature, and don't want to go to the standard texts, then the series of articles at

will be most helpful.

Mac Muir said...

GM: Your science of doom site is interesting. His thin shell problem is cute but has a problem. If the shell is in contact with the sphere then the inner surface of the shell would be constrained to be at the same temperature as the surface of the sphere. That is not the case he worked.

In general he seems to be missing the point that CO2 does not behave like water. Water has so many rejection bands that it begins to look like a broadband filter of varying transmittance. Water, while not linear by any means, is not opaque. CO2 has only three narrow rejection bands. Outside of those bands CO2 behaves like Nitrogen or Oxygen (emissivity and absorptivity are zero). Within those narrow bands it is fully opaque in distances much shorter the the depth of the atmosphere.

Anonymous said...

@Mac, you're welcome to proffer your theories there.

Anonymous said...

I'd be curious to hear what David thinks of fracking

Mark Bahner said...

"We have no backup planet, and, the time evolution of such things as ocean overturning and ice sheet changes means that we're committed to what we've done and are doing for millennia to come."

It will be fairly easy for the people of the 22nd century to lower CO2 levels to the pre-industrial concentration of ~300 ppm if they want to:

Global warming is reversible

Anonymous said...

@Mark, have you considered the other impacts of increased CO2?

Betting on an as-yet impractical technology some centuries hence is fanciful, to say the least.

It's rather like continuing to smoke and betting that cloned organs will be readily available before one is dead from heart disease/emphysema/cancer/etc.

Mark Bahner said...

"@Mark, have you considered the other impacts of increased CO2?"

What impacts do you think remain hundreds of years after CO2 levels return to pre-industrial levels? (Or "millenia," to use your original term.)

"Betting on an as-yet impractical technology some centuries hence is fanciful, to say the least."

It's completely practical even today, from a technical standpoint. It's simply very, very expensive...compared to the current world GDP. Compared to the world GDP that the IPCC expects in 2100--which is far lower than the GDP will probably be--it's not very expensive at all.

Anonymous said...

@Mark think sea level rise, ocean acidification, and ecosystem changes. Even if CO2 emissions are cut to zero, these effects will last for millennia.

Betting that global GDP will continue to grow unabated until CCS becomes relatively "cheap" isn't reasonable.

Mark Bahner said...

"@Mark think sea level rise, ocean acidification, and ecosystem changes. Even if CO2 emissions are cut to zero, these effects will last for millennia."

I'm not talking about cutting emissions to zero. I'm talking about actually reducing the CO2 concentration in the atmosphere back to pre-industrial levels. Ocean acidification would not simply stop, it would begin to reverse. Likewise, temperatures would begin dropping, so sea level would presumably begin to fall.

David Friedman said...


Two points:

1. Over a period of centuries or millenia, sea level rise even of many meters is a minor problem, since over that sort of time span houses get replaced, populations shift.

2. The IPCC high emissions scenario assumes continued GNP growth. That's one of the sources of the increased CO2 output.

Anonymous said...

@Mark, you're not taking into account the changes already built in to the system, that even dropping CO2 to zero won't change.

Anonymous said...

@David, to where will people move? Remember, manmade climate change isn't just SLR and ceteris parabus otherwise. Abandoning trillions of dollars of infrastructure won't be cheap to replicate inland, assuming there's an inland available.


I think you're getting close to the "infinite growth" fallacy.

Mark Bahner said...

"@Mark, you're not taking into account the changes already built in to the system, that even dropping CO2 to zero won't change."

First of all, "dropping CO2 to zero" would change just about everything...starting with killing all human beings on the planet. No plants will grow in zero CO2. No plants means no humans.

But assuming the people of 2100 reduce the atmospheric concentration of CO2 to ~300 ppm by the middle-to-end of the 22nd century, what effects do you think would last for hundreds of years...or "millennia"?

Anonymous said...


The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.

Mark Bahner said...


"This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop."

And that's nonsense. As I wrote in my blog post: "It's an indication of how strongly global warming alarmism is a religious matter that the paper was published with such a title."

The premise is that human beings somehow allow themselves to be significantly disadvantaged for 1000 years, even though it takes less than an hour to perform the analysis that I performed, which is to ask:

"Given the IPCC's projections for CO2 concentrations and CO2 emissions in 2100, and given the IPCC's expected gross world product (GWP) in 2100 and beyond, could the world spend 10% of its GWP to get the atmospheric CO2 concentration down to 300 ppm in a few decades?"

And the answer is, "Yes."

But of course most people don't know any science, and certainly haven't thought about how wealthy the world is likely to be 100+ years into the future, so they read papers like the one you cited, or the paper in Science, and think, "This must be good science."

Anonymous said...

@Mark, have you actually *read* the paper? Are you familiar with the concept of inertia?

Put it this way - if you're in car doing 60 mph down the freeway, and turn off the engine, does it immediately stop?

Anonymous said...

" to where will people move? "

Inland, and upward, assuming technological or economic progress doesn't make diking or other solutions viable.

"Abandoning trillions of dollars of infrastructure won't be cheap to replicate inland"

Infrastructure that is worth trillions today will not necessarily be worth trillions in 100 years.


Anonymous said...

@excel So, these displaced persons will be welcomed with open arms by those already living inward and upward? No potential for conflict? I don't think so.

Coastal cities, by and large, are very valuable. I wouldn't expect abandoning (say) NYC to be a negligible cost.

Mark Bahner said...

"@Mark, have you actually *read* the paper? Are you familiar with the concept of inertia?"

Yes, I've read the paper. Have you? And have you understood it?And have you understood the difference between the paper and what I am writing about?

Look at the CO2 concentrations in Figure 1. Solomon et al. have the worst-case concentrations peaking at about 1200 ppm in the year 2100, and then gradually declining to just below 800 ppm in the year *3000*.

Apparently, no one considered, "What would the size of the world economy be in 2200? 2400? 2800? 3000?" Or, "Do you suppose the people of 2100 or 2200 or 2400 might try to do anything about the high levels of CO2 in the atmosphere?"

Again, it just goes to show how much global warming alarmism is a religion that it was published in places like PNAS and "Science."

Mac Muir said...

AGW as Religion.

Many people persist in the thought of themselves and others as sinners.

They see mankind and man’s actions as basically sinful. Mankind is viewed as basically greedy, selfish and uncaring. These people often see nature, unspoiled by man as pure and holy. There is a win/lose aspect to this thinking. In order for something/someone to win something/someone else must lose.

Thus any action which changes nature must, perforce, be bad. The very idea that we might change something in a way which turns out to be accidentally beneficial is seen as ridiculous.

There is a karmic aspect to this as well. As man damages the environment, the environment will surely extract its revenge. (The fact that nature generally recovers relatively quickly from environmental damage is, of course, overlooked. This is not to ignore the fact that we have caused ecological damage, we certainly have, but mankind has been and continues to find ways to be less damaging.)

This creates an environment where it is easy to believe that any action, like burning fossil fuels must cause disastrous consequences.

But sometimes we do create positive outcomes. When john D. Rockefeller marketed cheap kerosine it largely dried up the market for whale oil which literally saved the whales from extinction. Was Rockefeller trying to save the whales? No, but his actions had that effect.

Remember photosynthesis. CO2 turns out to be one of the two main plant nutrients (the other being water). It turns out that plants need less water, are more resistant to disease, and grow better in a higher CO2 concentration. It is likely that this is part of the reason that the mass starvation predicted for the 1990's never happened.

Anonymous said...

@Mark, you're making the "infinite growth is possible" fallacy. Can the planet sustain any arbitrarily large number of humans living heavily energy-intensive lifestyles?

What about the entire rest of the biosphere? Can it withstand any alteration we can throw at it?

Who dictates the rules of our existence on this planet? Us or nature?

Anonymous said...

@Mac, did you ever get around to reading Weart's work?

The beginning part of your post is merely attacking a strawman. I'm no Gaia-worshipping Green.

David Friedman said...

GM asks:

"where will people move? "

As a rough rule of thumb, the coast shifts in a hundred feet for every foot of sea level rise. The current high emissions IPCC estimate has an upper bound of about one meter by 2100, so on average the coast shifts by about 100 meters. Run it a few centuries further, even assuming a ten meter rise, that still shifts coasts by only a kilometer, a little over half a mile. Look at a map and that's almost invisibly small.

If coasts shifted that far over night there would be huge problems, but over several centuries there are not. The amount of room for people is almost unchanged.

Meanwhile, the same warming moves temperature contours towards the pole. The increase in usable land area is several orders of magnitude larger than the loss from sea level rise.

Why would there not be an "inland" available? You are talking about tiny changes, seen from a geographical point of view.

There's a nice web page that lets you see the effects of sea level rise. Try playing with it:,138.1640625&z=13&m=7

David Friedman said...


You link to It's run by John Cook. For my view of Cook, with evidence you can check yourself, see:

David Friedman said...

GM writes:

"So, these displaced persons will be welcomed with open arms by those already living inward and upward? "

The piece you linked to about irreversible effects is talking about total sea level rise of a few meters. That moves coastlines inward by a fraction of a mile. You are imagining shifts of hundreds of miles.

It's worth actually looking at numbers as well as words.

Anonymous said...

@David, skepticalscience's articles almost always contain links back to the original literature. You're welcome to read those sources and then decide if SkS as a whole is suspect.

I find your argument against SkS shallow.

Anonymous said...

@David, rerun your analysis for Bangladesh and proclaim SLR there is a non-issue.

I've observed that most of the pooh-poohing of manmade climate change is a problem revolves around unsupported assertions. One is that global wealth will continue to climb such that adaptation later will always be cheaper than mitigation now. That's hardly always the case with current environmental problems. Think cleaning up old tailings piles from mines.

The other is a "deus ex machina" fallacy, in which a technological miracle will serendipitously arrive at some future time and make AGW entirely a non-issue, so we need do nothing now.

Arguments of these sorts are never accompanied by anything more than wishful thinking and handwaving.

Anonymous said...

Among those in the grip of the delusion that "global wealth will continue to climb" is the IPCC-- their emissions pathways, as given in the link GM posted, are based on global RGDP increasing by a factor of 5x-8x over the 21st century, and still increasing at the end of it.

David Friedman said...

GM writes:

"I find your argument against SkS shallow."

Would you like to explain what is wrong with it? Does "greenhouse gases contribute to warming" imply "humans are the main cause of warming?"

If not, then Categories 2 and 3 are not papers that hold that humans are the main cause of warming. That leaves Category 1, which contains not 97% but 1.6% of the relevant papers. Cook claimed in the later paper that the earlier paper found 97% for "main cause."

What is that other than a flat lie?

Do you not find it in the least suspicious that the original paper reported the sum for Categories 1-3 but not the individual numbers—when Category 1, principal cause, contained almost no papers?

Did you compare Cook's response to my argument with the arguments I actually made? Did you notice that he attacks me for an argument I did not make and ignores the argument I did make? Can you imagine an honest man acting in that way?

It's true that SKS links to the original papers. But almost nobody, I suspect including you, actually reads those papers, and most people don't have the expertise to judge them if they did read them. So what you are actually getting is not the original paper but what SKS claims it says.

I have tried the experiment of following the links, looking at the original papers, and comparing them to the SKS account. Have you? In my experience, doing so confirms my impression that SKS routinely misrepresents the evidence.

Anonymous said...

"What about the entire rest of the biosphere? Can it withstand any alteration we can throw at it?"

Followed by

"The beginning part of your post is merely attacking a strawman.


"you're making the "infinite growth is possible" fallacy."

Followed by

"Can the planet sustain any arbitrarily large number of humans living heavily energy-intensive lifestyles?"


"That's hardly always the case with current environmental problems. Think cleaning up old tailings piles from mines."

Followed by

"Arguments of these sorts are never accompanied by anything more than wishful thinking and handwaving."


Mac Muir said...

Questions for GM.
What level of CO2 reduction do you believe will be necessary? 10%, 20%, 50%, 75%, 95% What?

How do you propose to make those reductions?

Anonymous said...

@David, I do have the expertise to read and understand the literature, and SkS does accurately relay the content of the papers to its audience.

Anonymous said...

@excel was there a point in your post?

Anonymous said...

@Mac do you mean emissions or concentrations?

I prefer that we mitigate as much as reasonably possible so we have to adapt less. Mitigation includes a revenue-neutral carbon tax to level the playing field, and advanced nuclear in the mix of energy sources, along with renewables.

Most of the carbon in the ground should remain there.

Mark Bahner said...


You write, "I do have the expertise to read and understand the literature, and SkS does accurately relay the content of the papers to its audience."

That's demonstrably false. The single most important paper to SkS is their paper on the level of scientific consensus on global warming. Here is how they represent the results of that paper (capitalization and punctuation exactly as on their website):

“97% of published climate papers with a position on human-caused global warming agree: GLOBAL WARMING IS HAPPENING--AND WE ARE THE CAUSE.”

That is a blatant misrepresentation of the results of their paper, as David Friedman, I, and many others have pointed out.

It does no credit to your claim that you "have the expertise to read and understand the literature" if you can't understand and *acknowledge* the simple fact that SkS blatantly misrepresents the results of the most important paper on their website.

Anonymous said...

@Mark If you don't like Cook and his paper, that's one thing. To imply that SkS as a whole is suspect is little more than *ad hominem*.

Mark Bahner said...


You stated that, "I do have the expertise to read and understand the literature, and SkS does accurately relay the content of the papers to its audience."

Once again, that is blatantly false. SkS blatantly misrepresents the most important paper on their website. If you do not understand their blatant misrepresentation, or refuse to acknowledge it, either:

1) you don't have the expertise to read and understand the literature, or

2) you know that your assertion that "SkS does accurately relay the content of the papers to its audience" is blatantly false.

Anonymous said...

The theory of manmade climate change doesn't depend on SkS. I'm seeing echoes of the ongoing attacks on MBH98, as well as the stinky fingers of Monckton.

In any case, @Mark, there are several open questions I've left for you. Care to address them?

Anonymous said...

It's ad-hominem to suggest that something Cook wrote is suspect because of something else Cook wrote. To suggest that something Bahner wrote is suspect because of something Monckton wrote, on the other hand...

Mac Muir said...

You didn't give me any numbers.
A "revenue neutral" carbon tax - really? The whole real purpose of a carbon tax is as a major source of additional revenue in a way that the politicians can justify to the voters.

I agree on advanced nuclear (Thorium long term) But I do not believe the current political and regulatory environment will allow it. Meanwhile wind turbines will continue to slaughter birds and bats and making solar panels will continue to pollute so the crony corporatists can make lots of money to share with the politicians.

Neither wind or solar are real answers since neither is 24/7 and we have no way to store the amounts of energy that would be required to make these technologies major players.

I meant concentration.

Anonymous said...


"Meanwhile wind turbines will continue to slaughter birds and bats"

Crocodile tears.

"and making solar panels will continue to pollute so the crony corporatists can make lots of money to share with the politicians."

Thank goodness the carbon-based energy industry has *never* used its vast wealth to manipulate politicians. I mean, there is the little matter of the war we started in Iraq in the ME because of Iraq's oil, but other than that...

David Friedman said...

GM: You have told us that you think you have the expertise to read and make sense of the papers on the SKS site. Can you give us information about your background that will let us form an opinion on the subject?

If the person running SKS deliberately lies about his own work, isn't that a reason to distrust the site? I've offered evidence first that he lied about his own work, second that the work in question appears designed to be misrepresented, and third that he lied about my criticism in responding to it. That's a much simpler set of issues than making sense of linked papers, and all of the evidence is where you can check it for yourself. If you disagree, you should be able to show what is wrong with my argument.

For what it's worth, the SKS page I looked at recently was the one that claimed to refute CO2 fertilization. If you want to read that, look at the papers it links to, and express your opinion, I will be happy to point out why I thought it misrepresented their contents.

David Friedman said...

"The theory of manmade climate change doesn't depend on SkS. "


But a lot of things that people believe related to it do, since a lot of people making arguments, at least online, rely on SKS as a major source of information.

I mentioned the example of CO2 fertilization. If increased CO2 increases agricultural productivity, as one would expect, that's a reason to think that the result will be an increase, not a decrease, in the food supply. That's the opposite of the claim routinely made by people who regard AGW as catastrophic.

SKS claims it doesn't work, and I've been pointed at their page in arguments on the subject. If they cannot be trusted, then one has to either ignore their claims or actually read the papers they link to—and even the latter isn't entirely adequate, since they might be a biased selection of the literature.

Mac Muir said...

There is a great deal of data relating to higher levels of CO2 fertilizing plants. One article:

See also the NIPCC Report: "Climate Change Reconsidered" 2009 edition. Chapter 7 (pp 361-578) and Appendix 2 (pp 713 to 726)

Anonymous said...

@David, my background is nearly 30 years of study of the subject, interacting with many of the best known and most well-regarded experts.

Throw out SkS. Throw out Cook's papers.

What changes about the science itself?

Absolutely nothing. The IPCC AR5 attribution statement

"It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period."

is still true and correct.

Anonymous said...

@David, @Mac - if it was only CO2 changing under anthropogenic climate change, the claim of increased food supply might have some credibility.

However, since CO2 is rarely the limiting factor in food crop plant growth, other factors are more important, and some of those change under AGW.


for a meta-analysis for Africa and S Asia

Abstract: Climate change is a serious threat to crop productivity in regions that are already food insecure. We assessed the projected impacts of climate change on the yield of eight major crops in Africa and South Asia using a systematic review and meta-analysis of data in 52 original publications from an initial screen of 1144 studies. Here we show that the projected mean change in yield of all crops is − 8% by the 2050s in both regions. Across Africa, mean yield changes of − 17% (wheat), − 5% (maize), − 15% (sorghum) and − 10% (millet) and across South Asia of − 16% (maize) and − 11% (sorghum) were estimated. No mean change in yield was detected for rice. The limited number of studies identified for cassava, sugarcane and yams precluded any opportunity to conduct a meta-analysis for these crops. Variation about the projected mean yield change for all crops was smaller in studies that used an ensemble of > 3 climate (GCM) models. Conversely, complex simulation studies that used biophysical crop models showed the greatest variation in mean yield changes. Evidence of crop yield impact in Africa and South Asia is robust for wheat, maize, sorghum and millet, and either inconclusive, absent or contradictory for rice, cassava and sugarcane.

Mac Muir said...

GM: I suspect the report you cited is fiction (based on computer simulations only) as it flies in the face of all the studies that I have seen.The data is pervasive and persuasive: CO2 does indeed improve plant growth substantially.
For example, a 300 ppm increase in CO2 results in:
Wheat 83 studies: +64.9% increase.
Millet 2 STUDIES: +12%
Sorghum 9 studies: +26.8%
Rice 64 studies +49.7%
Sugarcane 6 studies +11%
Cassava 1 study +56%

Keep in mind that we have historical data relating to temperature and food production: The MWP was very prosperous in both Europe (Especially northern Europe and Greenland)and China. The little ice age was hard times.
The same was true in the Roman warm period.

Anonymous said...

@Mac, you need to do better than that.

CO2 is hardly the limiting factor in food crop production. Besides, "CO2 is good for plants" misses the point that unwanted plants will grow better too.

Mac Muir said...

You keep making the assertion that CO2 is not the limiting factor in food crop production while the evidence and logic both point to just the opposite.

Plant growth would be limited by whatever nutrient it runs out of first. We can irrigate and fertilize for everything but CO2 in open fields. It makes sense that if we do then plants will be limited by the ability to capture CO2. Likewise extra CO2 causes plants to need less water.

Commercial plant nurseries often add additional CO2 to their greenhouses. They would not do it if it didn't work.

Likewise food plants are more likely than weeds to get fertilizers that match their needs so your harping on weeds is just silly.

Your post of climate crocks is probably aptly named: i.e. a crock.

Anonymous said...

@Mac, do you think we can replicate the conditions in a greenhouse over the entirety of the agricultural regions on the planet?

What's the source of your table? You didn't provide it.

There are many elements in agricultural productivity, and you're focusing on just one.

It's too bad you didn't watch the video. You wouldn't come across as so juvenile if you had.

Mac Muir said...

I did provide the source of the table in a previous comment. It is appendix 2 of the NIPCC report.

My point with greenhouses is that CO2 does provide significant fertilizing effects.

We have a recent study that says plants worldwide flourished by 11% between 1982 and 2010 due to additional CO2.(Referenced in the Forbes article.)

You're constant denial of this fact is getting old and is making you look very juvenile.

Yes Russia has droughts. That is nothing new.

I have already demonstrated using physics that CO2 is not the cause of warming. Something that you have not disproved. Instead you have attacked me personally for taking that position. Talk about juvenile.

Would you like a likely explanation of the so called warming of the twentieth century.
Well here is one:

It is generally claimed that the planet’s temperature has gone up 0.6-0.7 degrees C in the last century. Recent disclosures bring this assertion into question. It appears to be possible that our reported global warming in the last century is not really real and the apparent warming is totally a result of urban island effects, the effects of heat sources near the thermometers, repainting thermometer enclosures, shifting sensor locations to favor warmer locations, other instrumentation errors and widespread cooking of the books.

Only 3% of US temperature sensing stations are properly sited by NOAA standards. 89% of them will read high by more than 1 degree C, 69% by more than 2 degrees and 11% by more than 5 degrees. This alone is enough to more than account for the reported rise in temperatures. It is likely that similar conditions apply worldwide.

The temperature sensors used to be in whitewashed (calcium carbonate pigment) boxes. In 1979 this was changed to latex paint (titanium dioxide pigment). Both are white in the visible band but the latex paint is more absorbing in the near infrared. An experiment was conducted in 2007 with side by side boxes and super well calibrated sensors. The latex painted box read higher by an amount which varied over the course of the day between 0.3 F and 0.8 F. This is a significant part of the reported rise over the century (1.2 F). This would seem to totally explain the apparent 1979 rise.

Anonymous said...

@Mac don't insult our intelligence with the NIPCC "report".

And don't insult our intelligence with Watts' baloney nonsense.

Remember, Tony said that whatever BEST came up with, he would accept. When BEST showed that the analyses of surface temperature by the various groups that compile them were correct, Tony went back on his word and is sticking with his incorrect theories.

You've got an impossible task if you think warming surface temperatures are somehow wrong. You can tell Roy Spencer that he's in on the conspiracy, because USH shows warming too.

You really ought to spend the time and effort to read Weart's work.

Mac Muir said...

I started looking at these issues about twelve years ago. At first I thought AGW was probably very real and the fixes proposed by the Kyoto treaty woefully inadequate. I continued reading. I wrote a booklet on the subject. I have a degree in Electrical engineering as well as a strong interest in physics. In the 1970's I went to work (Wrong word - the culture there was that you said that you were "At the lab" rather than worked there but I actually worked.) on fusion research at a very Prestigious University (that I will not name). The culture was that "We will all retire from here still working on the problem. The AEC and later DOE would not and still seem unwilling to fund any project which might lead to a working fusion reactor in the near term. The hypocrisy got to me and I left on ethical grounds.I am still rooting for fusion and still believe in it's possibilities but believe DOE will not get us there.
I have also come to believe that fission (including Thorium fuel in the long term) works.

But back to my main point. The more I studied global warming the fishier it was getting. Michael Mann's hockey stick eliminated both the MWP and the little ice age, both well documented historical events yet the IPCC featured it prominently. The publication of the scientific papers in AR4 were delayed so they could be "edited to conform with the summary." The summary was a political document. This is NOT science, this is bad politics.The IPCC and other AGW proponents have made many claims about disastrous events that were already supposed to have happened but didn't and still aren't.

I applied my scientific smell test and the AGW case fell apart.

There is a great deal of misinformation out there, almost all of which is put out by AGW proponents.

The NIPCC reports are far more credible than the IPCC reports.

As an EE I know something about linearity and non-linearity and feedback.

Then I found what I reported on in an earlier comment. Remember my reference book predates the AGW controversy and thus cannot be misinformation.

GM: I am willing to discuss and even debate the science but you seem to be unwilling to do so.

David: Thank you for being willing to put up with all of this.

Anonymous said...

@Mac, you have only evinced a glaring ignorance of the basics of the subject. You claimed (at 6:11 AM, October 25, 2014) that the theory of manmade climate change was relatively new but you weren't aware of any of the work done by Fourier, Tyndall, Arrhenius, Callendar or Plass. You've clearly not read Weart's work, and have discarded the entirety of the (admittedly poorly-named) "greenhouse effect" as a theory. That's analogous to refusing to accept that the earth is a spheroid. Yes, it's that out there.

You prefer the NIPCC (a piece of nonsense explicitly designed to deny, obfuscate and confuse by an extremely conservative think-tank) over the IPCC.

I detect much confirmation bias and the Dunning-Kruger effect at work.

Mac Muir said...

GM: Go back and reread my Oct 25th piece. I made no such claim. I did not say the concept was relatively new only that it was widely publicized after Thatcher went after the coal miner's union.

I have not read either the NIPCC reports or the IPCC reports in their entirety but I have read parts of both and I find the NIPCC reports to be far less political and more scientifically plausible than the IPCC reports.

This debate should be about the science and not about the politics.

The experiment about repainting the Stevenson enclosures for example: I described an experiment and its result. You attacked the scientist. This experiment would be easy to replicate. You did not cite anyone else trying it and getting a different result. You just said: "don't insult our intelligence with Watts' baloney nonsense."

My 5:02 am Oct 24th. Was pure science. Basic physics relating to how CO2 works in the atmosphere. It leads to the conclusion that CO2 is not causing any significant warming now. You made no effort to dispute any part of my analysis but dismissed the whole thing out of hand.

You tend to not answer the questions posed to you but attack and dismiss out of hand any thought you disagree with.

I think we can safely say that we "detect much confirmation bias and the Dunning-Kruger effect at work" on the part of GM.

I feel sorry for you.

Anonymous said...

@Mac, once you start proving that you're familiar with the science, your comments may have some utility.

Until then, your views aren't worth much.

Start with Weart.

Oh, and from 1958:

David Friedman said...

A few comments on the GM/Mac exchange:

"Michael Mann's hockey stick eliminated both the MWP and the little ice age, both well documented historical events yet the IPCC featured it prominently."

They are well documented historical events for substantial parts of the northern hemisphere. Mann's claim, as I understand it, was that they were not paralleled elsewhere, hence did not hold for the global average. He may well have been wrong—they seem to have reappeared in later versions of the paleoclimate estimates—but not as obviously wrong as you imply.

Also, I think you have to distinguish, in talking about the IPCC, between the scientific sections and the summary for policymakers. The latter is a political document and pretty clearly slanted in an alarmist direction. The former is probably wrong in some details—I've offered evidence here that its predictions have tended to run high relative to what happened. But I don't think it fails Mac's smell test.

On the other hand, I think the broader movement does, for reasons I've discussed on this blog at some length.

Unless I missed it, Mac never responds to the point that satellite data, produced by someone quite skeptical of the CAGW story, confirms the general rising trend of global temperature.

Anonymous said...

@David, you have a Ph.D. in physics; you should be able to see the claims that there's no "greenhouse effect" or that CO2 has no impact on the climate system as the dross that they are.

Mac Muir said...

David: Thank you for your comments.

I have recently read of data indicating that the MWP was indeed global. I am sorry but I cannot give you a link.

Remember the MWP and Little Ice Age were prominent in the graph in AR1.

In terms of my smell test and the IPCC reports. Many of the scientific papers do pass a reasonable smell test. Some others do not. My main complaint here is how the alarmist summary has been allowed to contaminate the scientific papers.I did not read the papers after the announcement that the papers were being edited to conform to the summary. My thought was: Why bother.

I seem to remember an incident several years back where a news conference was held where a paper was totally misrepresented by the head of the committee involved.

I do not claim that there is no greenhouse effect. There clearly is. I do claim however that CO2 is not a major contributor to planetary warming at this time. CO2 takes out three narrow bands and as such that warms the planet but those three bands are now fully opaque so additional CO2 will have almost no additional effect.

I also do not say that climate change does not or cannot happen. the climate is constantly changing in one way or another.

I totally missed the point about satellite data confirming a warming trend. Last I knew we were flat for the last 15 or so years.

A general comment: My skepticism about AGW has grown more out of the writings and speeches of the pro-AGW people than the skeptics.

GM: You do not have any credibility with me as I do not have any with you. Can we agree to disagree and leave it at that.

Anonymous said...

@Mac, please read

if a skeptical friend hits you with the "saturation argument" against global warming, here’s all you need to say: (a) You’d still get an increase in greenhouse warming even if the atmosphere were saturated, because it’s the absorption in the thin upper atmosphere (which is unsaturated) that counts (b) It’s not even true that the atmosphere is actually saturated with respect to absorption by CO2, (c) Water vapor doesn’t overwhelm the effects of CO2 because there’s little water vapor in the high, cold regions from which infrared escapes, and at the low pressures there water vapor absorption is like a leaky sieve, which would let a lot more radiation through were it not for CO2, and (d) These issues were satisfactorily addressed by physicists 50 years ago, and the necessary physics is included in all climate models.

David Friedman said...

"Last I knew we were flat for the last 15 or so years."

I haven't checked the satellite data in particular, but the climate figures I've seen suggest that temperatures (not counting possible deep ocean warming) have been flat since 2002. My point was that I thought the satellite data roughly agreed with the surface data about the upward trend from about 1910 on. I thought you had suggested that problems with the surface temperature measurements cast doubt on that, but I haven't followed all of the lengthy exchange so perhaps I misunderstood you.

Anonymous said...

@David, surface temperature measurements do have problems, but they are understood and compensated for. It's a myth that surface temperature analyses are wrong, or manipulated with a political goal in mind, or some other such nonsense.

The BEST project dispensed with all that, but the hardcore pseudo-skeptics are clinging to falsehoods.

Mac Muir said...

David: I haven't checked satellite data in particular either. That data clearly does not go back to 1910. I don't know when the satellite data really came on line and when it became accurate. I do not know one way or another how well satellite data tracks surface data.

I also do not know how long heat sources have been in place around the temperature sensors. I would expect that to be quite variable.

Many of the graphs that I have seen show net cooling from 1940 to 1979. We had a "New ice age" scare back in the late 1970's.

I was saying that problems with surface data do indeed cast some doubt on the warming trend in the 20th century. I am not saying the planet cooled then but I am saying that a reasonable doubt exists in my mind.

If the experiment regarding repainting the sensor enclosures is correct that explains the step function in 1979.

If the pattern of previous ice ages and interglacials were to continue then we are about due for the next ice age.

Anonymous said...

@Mac Please read the following:

"The Myth of the 1970s Global Cooling Scientific Consensus"

On the reliability of the U.S. surface temperature record

Anonymous said...

"was there a point in your post?"

Yes, a sincere call for you to clean up your act.


Mark Bahner said...


You write, “The theory of manmade climate change doesn't depend on SkS. I'm seeing echoes of the ongoing attacks on MBH98, as well as the stinky fingers of Monckton.”

Here’s what I’m seeing. You made a blatantly false statement: “I do have the expertise to read and understand the literature, and SkS does accurately relay the content of the papers to its audience.”

David Friedman and I pointed out that SkS blatantly misrepresents the findings of their most important paper. Now, rather than acknowledge that SkS blatantly misrepresents their paper’s results (or disputing that fact…which would be hard to do, since it’s indisputable) you refuse to admit your statement was incorrect. And you make spurious and ad hominem attacks on *my* integrity. I see your actions as dishonest and dishonorable. That’s how I see it.

Mark Bahner said...


You write, “@Mark, you're making the "infinite growth is possible" fallacy.”

Where do you think I’m “making” that “fallacy”? I presented an analysis that demonstrated that spending approximately 10 percent of the gross world product (GWP) starting in 2100 would enable the atmospheric CO2 concentration to be lowered to approximately 300 ppm in a few decades. That analysis was based on the IPCC’s estimates for GWP in the year 2100. Do you think that the IPCC is also “making” that “fallacy”?

The IPCC’s estimated GWP in 2100 ranges to a bit above $500 trillion (year 2000 dollars). Do you think the “limit” to GWP is above or below $500 trillion (in year 2000 dollars)? What do you think the “limit” is?

You ask, “Can the planet sustain any arbitrarily large number of humans living heavily energy-intensive lifestyles?”

-->”Arbitrarily large” could mean “infinitely large”…so no, I don’t think the planet can sustain an infinite number of humans in their current form. I do think the planet can sustain 15 billion people with per-capita annual incomes of more than $1 million.

And, "What about the entire rest of the biosphere? Can it withstand any alteration we can throw at it?"

-->I don’t think humans have the capability to end all life on earth, if that’s what you’re asking. Right now, the most deadly thing I think humans could do would be a global thermonuclear war. Even that I don’t think would end all human life…let alone all life on the planet. But obviously something like that would make it very difficult for much life on the planet...especially human life.

You close with, “Who dictates the rules of our existence on this planet? Us or nature?”

-->You’d have to specify what “rules of our existence on this planet means” before I could answer that. If you’re thinking about things like the existence of oxygen in the atmosphere, obviously we’re not creating the oxygen we need to live.

tonyon said...

a SOLAR ENERGY CAR made by amateurs have crossed Australia. Why CAR´S FACTORIES do not want to know that?. Petroleum´s economic interests. Shame politicians