Global Warming Debunked?

limbicsystem writes, "I'm a scientist. I like Al Gore. I donate to the Sierra club, I bicycle everywhere and I eat granola. And I just read a very convincing article in the UK Telegraph that makes me think that the 'scientific consensus' on global warming is more than a little shaky. Now IANACS (I am not a climate scientist). And the Telegraph is notoriously reactionary. Can anyone out there go through this piece and tell me why it might be wrong? Because it seems to be solid, well researched, and somewhat damning of a host of authorities (the UN, the editors of Nature, the Canadian Government) who seem to have picked a side in the global warming debate without looking at the evidence." The author of the Telegraph piece is Christopher Monckton, a retired journalist and former policy advisor to Margaret Thatcher.

Comments

Re:you'll get answers

[FhnuZoag]

A bunch of errors leap up from a random scan.

Hansen's testimony to congress: Hansen presented three graphs, giving three possible scenarios of future events. The 0.3 (in fact, 0.45 C) claim comes from Scenario A.

http://www.cato.org/testimony/images/pm072998a.gif

But the fact that it is called Scenario A is because there are also scenario B and C. A is a 'business as usual' scenario, involving exponential growth in emissions. What happened since 1988 was nothing like that. If anything, industrialisation declined in the West, creating a situation closer to B and C - moderate controls to emissions.

http://www.giss.nasa.gov/edu/gwdebate/00fig1.gif

It's not like this is secret information. NASA itself has discussed this.

The objective was to illustrate the broad range of possibilities in the ignorance of how forcings would actually develop. The extreme scenarios (A with fast growth and no volcanos, and C with terminated growth of greenhouse gases) were meant to bracket plausible rates of change.

By quoting this assertion, the author of this article has shown that he is either deliberately deceptive, or has not looked at all of the evidence. Don't listen to the regurgitated rants of this non-expert.

Re:Great Site For Debunking

[Macthorpe]

I'm hoping that was a joke, because I thought it was fairly common knowledge (amongst those interested in this kind of thing, anyway) that JunkScience is maintained by someone in the employ of ExxonMobil and Philip Morris, a Mr. Steven Milloy, who also works for Fox News. Hardly a neutral point of view, or an authoritative source.

There are plenty more reputable sources to find your debunkings, most of them far preferable than "JunkScience".

So many lies.

[FhnuZoag]

Let's carry on debunking this debunkation, then.

First, the UN implies that carbon dioxide ended the last four ice ages. It displays two 450,000-year graphs: a sawtooth curve of temperature and a sawtooth of airborne CO2 that's scaled to look similar. Usually, similar curves are superimposed for comparison.

Yes, but where did the UN actually say that CO2 ended the ice ages? How is the author reading their minds? Such a view would certainly be contrary to must of mainstream science, of course, so where's the evidence that the author isn't setting up a strawman?

The Co2 graphs show the reliability of ice core CO2 data as a proxy for finding out historical temperature levels, and also the potential for positive feedback effects if temperatures rise. They give an idea as to the sensitivity of the situation to perturbations.

They gave one technique for reconstructing pre-thermometer temperature 390 times more weight than any other (but didn't say so).

So how does the author know, then?

They used a computer model to draw the graph from the data, but scientists later found that the model almost always drew hockey-sticks even if they fed in random, electronic "red noise".

This is pure and simply a lie. It's a lie, because all of these critics have ever show is the tendency for hockey sticks in PV01. But PV01 is a certain statistical consequence that is not the same as the actual reconstruction. Studies searching for the hockey stick tendency in the full reconstruction have come up with nothing, because there are other components in the full reconstruction that cancel out the first term.

http://www.telegraph.co.uk/news/graphics/2006/11/0 5/nwarm05.gif

This graph is comparing apples to oranges. The top graph is a global temperature anomaly graph. The bottom is the temperature of a relatively small continent, dominated by a warm ocean current. One is a average data over the world, and the other is strongly affected by local effects - such as the medieval warm period. The top graph is what global warming is talking about. The bottom graph is not relevant to the debate at all.

You don't need computer models to "find" lambda. Its value is given by a century-old law, derived experimentally by a Slovenian professor and proved by his Austrian student (who later committed suicide when his scientific compatriots refused to believe in atoms). The Stefan-Boltzmann law, not mentioned once in the UN's 2001 report, is as central to the thermodynamics of climate as Einstein's later equation is to astrophysics.

From wikipedia:

The Stefan-Boltzmann law, also known as Stefan's law, states that the total energy radiated per unit surface area of a black body in unit time (known variously as the black-body irradiance, energy flux density, radiant flux, or the emissive power), j*, is directly proportional to the fourth power of the black body's thermodynamic temperature T (also called absolute temperature):

Stefan Boltzmann applies to a perfect blackbody. The Earth is not a perfect blackbody. In fact, not alot of things are. Doesn't it seem wrong to say that energy exposure always raises temperature to the same degree regardless of the object?

And so on and so forth.

Re:So many lies.

[The_Wilschon]

Stefan Boltzmann applies to a perfect blackbody. The Earth is not a perfect blackbody. In fact, not alot of things are. Doesn't it seem wrong to say that energy exposure always raises temperature to the same degree regardless of the object?

IAAPhysicist, and I can tell you that the Stefan-Boltzmann law applies quite well to an awful lot of things, even though they are not perfect blackbodies. For a perfect blackbody, the Stefan-Boltzmann law is exactly right. For most other things, it is a quite good approximation. The earth is far closer to a perfect blackbody than you might expect.

Re:So many lies.

[icensnow]

The earth is far closer to a perfect blackbody than you might expect.

IAAClimatologist, and the earth-atmosphere-clouds system is not a surface and follows the Stefan-Boltzmann blackbody law quite poorly. That's why we have a greenhouse effect. Usually, we parameterize outgoing longwave flux in a way that the sensitivity to temperature is about half of what S-B predicts. A reference to which I cannot provide a link without (c) violations: Bintanja, R., 1996: The parameterization of shortwave and longwave radiative fluxes for use in zonally averaged climate models. J. Climate, 9, 439-454

Re:So many lies.

[tbo]

I am also a physicist. Lambda is dT/dP, evaluated at some temperature approximately equal to the earth's mean surface temperature. Taking the derivative and inverting, you get dT/dP = 1 / (4 sigma epsilon T^3). For epsilon = 1 and T=280 K, this gives lambda ~= 0.2. Wikipedia claims the average albedo of earth is about 30%, which very roughly implies the emissivity epsilon = 0.7 (since a blackbody is 0% albedo, and perfect reflectivity is 100% albedo). I'm ignoring frequency dependence and other effects, but this is a first order calculation. With that value for epsilon, I get lambda = 0.29 for the aforementioned parameters. So far, things look good for Monckton.

Now, let's try to refine our estimate of epsilon to account for frequency dependence. The 30% albedo given by Wikipedia is based on reflection of sunlight, and is thus probably heavily weighted to the visible spectrum, which is where the sun's radiated power peaks. Earth's thermal radiation, on the other hand, peaks in the infrared, since earth is much cooler. Due to the natural greenhouse effect, the 30% albedo may not be accurate at infrared frequencies. Thus, we want to calculate epsilon', the emissivity of the earth at infrared frequencies. The natural greenhouse effect provides an excellent mechanism for us to do this. Let s be the solar constant, 1366 W / m^2. Multiplying by (1-0.3) to account for the albedo of earth, and dividing by 4 to account for the ratio of the earth's cross-section to its surface area, we obtain an average absorbed power flux of 240 W / m^2. We then solve the Stefan Boltzmann Law to determine the value of epsilon' necessary to achieve equilibrium, substituting Earth's mean surface temperature for T: 240 W / m^2 = sigma epsilon' T^4 ==> epsilon' ~= 0.7. Thus, it looks like our first estimate was good.

To recap, we use the Stefan-Boltzmann Law, the (measured) albedo of earth, the approximate mean temperature of earth, and the solar constant to estimate the effective emissivity of earth for infrared. We find it agrees with Earth's mean albedo. Using this value of the emissivity and the Stefan-Boltzmann Law, we estimate lambda as 0.29 K / (W / m^2), in good agreement with Monckton, and poor agreement with the other estimates he mentioned.

Re:you'll get answers

[Ruff_ilb]

I was just ready to mod, but your comment caught my eye.

There are several things to this:

A) Reducing emissions doesn't mean an overall reduction in green house gasses - it just means a reduction in the rate of increase. So we're still increasing the amount of greenhouse gasses, just at a slower rate.

B) The environment doesn't turn around that fast; it probably takes longer than 30 or so years for our efforts to have a noticible effect.

C) Our measurement systems might not be precise enough to account for any differences, even if they did happen. AFAIK, a lot of the evidence comes from really old-school ice-core samples from a long time ago. Now, it's hard to prove a correlation (much less causation) with only 30 years of data, however precise. Climatologists are much more worried about (and, thus, I think, do more research about) trends spanning at least a century.

More debunkation.

[NeutronCowboy]

You started well, so I'll just stick to what I know.

* Monckton mentions that there is a direct correlation between number of sunspots and grain prices falling, attributing it to the fact that more sunspots mean that the sun is hotter. Actually, that's wrong. Sunspots are cooler regions on the surface of the sun (3800 K vs 5400K on the rest of the surface), which means that the sun is actually radiating *less* energy in the visible and infrared spectrum. So his entire point completely falls apart with this basic item of astrophysics.

* Monckton categorically states that the temperature of the oceans has decreased, without using sources. From what I know though, temperatures have increased. Can't find a bullet proof link for it (was looking for NOAA timelines, but no luck), but you can use coral-reef die-offs as a good proxy. There was also a lot of hubbub when people tried to tie the increase in surface temperature of the Gulf of Mexico to the increased strength and number of Hurricanes that hit the US coast.

These are the two things that I categorically to be false. As for the rest of his arguments, they lack the data support I would expect from a debunking report. For example, why exactly did the ICCP remove the old temperature graph that showed in extreme fashion the warm and cold periods of the middle-ages? Besides, the temperature differences are still there - they are just not as blatant as before. There are also his 10 points which he thinks needs to be proven for Global Climate Change to be true, and what he thinks of them. Point 1 is a nice straw man, as someone pointed out already. Point 3 is another one, as people aren't arguing that the sun doesn't influence temperatures. They are arguing that the sun is less important than greenhouse gases. For the other points, I can give him the benefit of the doubt, even though all have significant problems with their wordings and his assessment of them.

In short, he might not be a shill - but there are enough problems in his "debunkation" to make me doubt the sincerity of his approach and his intentions. This might still be ok, if there weren't some massive errors in some of his arguments, which completely invalidate the points he is trying to make. As a result, I'm filing this under "waiting without bated breath to be properly ripped apart by people who know more".

Quite frankly, one reason I'm confident that we are in the beginning of Global Climate Change is that the only counter-arguments I see are poorly thought out, rife with personal attacks, lack data and make lots of statements without supporting data. If a group arguing for a position sounds like a bunch of idiots, I tend to take the opposite view.