The film claimed that the role of human emissions in climate change has
been exaggerated, and that changes in the sun and cosmic rays could be to
blame instead — claims that have been repeatedly discussed and rejected by
climate scientists. In February, the UN’s Intergovernmental Panel on
Climate Change said that a sharp rise in temperatures seen in the twentieth
century was “very likely” to be caused by human activity.

Unfortunately the proposition that carbon dioxide is “very likely” to be the cause is almost certainly false, as is the claim that carbon dioxide has any measureable warming effect. Such a warming from carbon dioxide has never been seen in any ice core, and the only way that carbon dioxide can be decided upon in climate models is to a) force the concentration to rise exponentially and b) apply various multipliers and positive feedbacks. Neither of those two things are happening in the real world.

The most disturbing part about the global warming hype is the application of a “mathematical” view as to what climate scientists believe, as if such things meant anything in science. It is, in fact, a political spin put upon what a very few people believe about the science whose conclusions are already agreed before the science has been completed.

Do I really have to point out the fallacy of argumentum ad populum?

1) Again, if you read only one thing, read Ruddiman’s book.

2) http://en.wikipedia.org/wiki/Greenhouse_gases is actually not bad.

3) All other things being equal, more CO2 and CH4 = jhigher temperature, but of course other things are never equal. For instance, a really good volcanic erurption could drop the temperature substantially for a year [Google: year without summer].

4) Be warned that the earth is like teakettle: if you fill it and put it on the fire, ti doesn’t boil instantly. Scientists calculate lag times for various effects: increases in CO2 have lag times of muitiple decades: Ruddiman [p. 155 describes this clearly].

Like I said, I don’t think the patient is going to die … but I do suspect that the history books of 2400, assuming there are some, are not going to have kind words about the centuries in which people consumed:
- all the reasonably-accessible oil and gas
- most of the coal
- a lot of aquifers

One can only hope that we achieve sustainable high technology, because if there’s any collapse, it will be difficult to rebuild.

I suggest not listening to clueless doomsayers … but I worry hard when I listen to sensible, highly-regarded scientists (like Ruddiman, or James Hansen, or Stephen Schneider) .

Again: please read Ruddiman, if you do nothing else.

Thanks for all the information.:) I can see that it’s probably best if I also spend some time reading through the IPCC Scientific Basis report as well. What I need to find out in more detail is the linkage between carbon dioxide and temperature changes, and I’m sure the IPCC report will cover this.

I have looked at Prof. Fred Singer’s website before. I view his statements as being as partial as those made by people on the opposite side of the spectrum, like the Green Party. When looking at the economic predictions, my feeling was that the end of the world scenarios given in the press could be viewed as scare-mongering:

‘Table 10 suggests that, in terms of percentages of world GNP, damage is relatively low, even for +2.5 degrees Celsius. The damages are not evenly spread. In general, developing countries lose more than developed economies. Some models suggest no real net damage to rich countries.’

http://www.publications.parliament.uk/pa/ld200506/ldselect/ldeconaf/12/1209.htm#a48

I think I’m correct in saying that economists like Professors Tol and Mendelsohn do not dispute the climate change science, but have concerns about the way the economics are assessed.

I appreciate your description of the climate modelling, but I do think that there are valid concerns about the economic and sociological predictions used in the climate change forecasts. For instance, the latest IPCC Summary for Policymakers says that all of the emissions scenarios should be viewed as being equally plausible, but in the evidence presented to the UK House of Lords economic affairs select commitee on climate change, some experts think that some of the scenarios are more likely than others. Some of the concerns raised about the emission scenarios include perhaps over-optimistic predictions of economic convergence of the developing and developed world, and what some would feel are population growth estimates that are excessive (the A2 scenario predicts a 15 billion world population in 2100).

Good questions (sorry for delay, it took a litlte while to dig out web-accessible references, rather than marked-up textbooks )

1) First, my statement about temperature change rates was lamentably imprecise, and to be truly accurate, would have needed a longer explanation with a lot of qualifiers. There have certainly been abrupt climate changes, especially in the Northern Hemisphere, generally believed to be state changes in ocean water circulation.
Of these, the Younger Dryas period is especially well-studied:
http://en.wikipedia.org/wiki/Younger_Dryas

See also Dansgaard Oeschger Events:
http://en.wikipedia.org/wiki/Dansgaard-Oeschger_event

Of course, major volcanic eruptions cause sudden drops in temperature, and then fairly quick rises as the sulfates drop out of the atmosphere.

(I’ll explain later why I was ignoring all these as irrelevant to the current changes.)

As to how one knows about temperatures over longer lengths of time, while we’d love to have had thermometers around, we didn’t so people use various “proxies”, of which one of the most important is Oxygen-18 isotope percentages in ice cores and ocean sediments:
http://en.wikipedia.org/wiki/Oxygen_isotope_ratio_cycle

All of this can be seen together in:
http://en.wikipedia.org/wiki/Temperature_record, with expansions:

http://en.wikipedia.org/wiki/Image:Five_Myr_Climate_Change.png [1]
http://en.wikipedia.org/wiki/Image:Ice_Age_Temperature.png [2]
http://en.wikipedia.org/wiki/Image:Holocene_Temperature_Variations.png [3]

and http://en.wikipedia.org/wiki/Sea_level_rise

1) Many millions of years ago [1] it was warmer, and of course the sea level was higher, and it was a different world, of course [orbital state, continental arrangements, etc].

2) If you look at the last 800,000 years [2], the temperature may well have been higher (a little) several times.

3) If you look at the last 12,000 years [3] , and especially at the embedded chart of last 2,000 years, you see the vertical line at the left, i.e., temperature rising very fast. That is *not* as fast as Younger-Dryas-like transitions up or down], but I was ignoring them is that the recent temperature rise is clearly not one of these. I.e., normally, there are bunch of slow-motion effects recorded in the ice-cores and other proxies, with occasional lightning-fast state-switches likely caused by thermohaline flow changes. Under pre-human-civilization circumstances, except for these state-switches, there was enough inertia, and slow-enough moving causes, that it’s hard for circumstances to change very quickly. On longer time-scales temperature correlates with CO2/CH4 [sometimes ahead, sometimes ahead, sometimes behind, generally for well-understood reasons]. Dryas-like events are odd in that CO2 was going up beforehand; then the temperature dropped; then the CO2 dropped (for a while).

I.e., in each ice-age cycle (about 100,000-year, lately), what seems to happen, roughly is:
a) it’s cold.
b) Then, orbital mechanics starts to warm things, and as it does, CO2 and CH4 go up, and then postive feedback from that helps the temperature rise faster, to some peak. If you look at the sawtooth graphs, this takes thousands of years to get a rise of about 7 degrees C.
c) Then, with jiggles the temperature slowly goes down again.
c) Recent effects: our interglacial just looks very different from the others, and here’s a reasonable analysis, including other explanations:
http://en.wikipedia.org/wiki/Attribution_of_recent_climate_change

In any case, I personally think that it is relatively fruitless to try to make statements like: “it is hotter than it has been for X years” as we may not have data precise enough for that, and in any case, it’s enough to know;
a) We are at the high end of the temperature range (over last million years)
b) CO2 in atmosphere is exceptionally high (in last million years), going up very fast.
c) Temperature forcing from CO2 is pretty well understood, and it has been raising the global termperature faster than we’ve seen from all the other usual cyles.

2) Testing models: there’s never as much data as people would like. I used to build supercomputers and work with their users, who include weather, oceanography and climate researchers, and they always wanted more data.

However, people get confused about the role of the models. people identified the possibility of human-induced warming without having the models, and most of the major effects were understood well before computers were good enough to do much about this.
Briefly, if one knows that:
- A given concentration of CO2 has a given “forcing” effect on temperature
- CO2 concentrations are going up very fast
- CO2 doesn’t drop out of the atmosphere very fast, hence there is a lot of momentum built into the system [especially the oceans].
- Orbital circumstances don’[t change very fast
- 11-year solar sunspot cycles have minimal effects
- Solar irradiance varies, and the current high level certainly contributes to some of the temperature rise since the Little Ice Age, but even if it goes back down to the equivalent of the Maunder Minimum, that's not going to eliminate the CO2 effects.
- We have 6B people on the planet, and if we're "lucky", maybe we'll stabilize around 9B (absent big pandemics or nuclear war,)

Then, we can expect the temperature to go up for a while, no matter what we do. A lot of the modeling is to try to better calibrate various "what-if" scenarios. Put another way, the idea that we're going to have serious global warming doesn't just arise from computer climate models...

3) Regarding Popper & falsifiability & models: as I noted, science works by getting successively-better approximations to reality. In some cases, we don't have the data to choose between two different models, and sometimes we never will. In other cases, new data arrives, or we get more precision, and well-established theories are over-turned. One of the reasons I recommend Ruddiman's book is that he doesn't just describe the current state of thought, he talks about the history of climate theories, and why they changed over time, and how.

I don't know Lindzen personally, although I know some people who do. He has certainly tried to find mechanisms that would ameliorate the temperature rise [the "IRIS" hypotheis], but so far, other evidence hasn’t confirmed this very well. Some good scientists are puzzled abotu why he seems so sure.

it is not a question of cut-and-dry presentation. I’ve heard very good scientists carefully present alternative scenarios, with careful caveats. But the trouble is, thistakes a lot of time, and background, and the popular press doesn’t have the space and time to do that. I sympathize with Lindzen over one or two criticisms with IPCC and the TAR, but really, the reason there is a general consensus about the overall effects is that the evidence is overpowering, and been piling up rapidly.

The people who have been really sure are the “denialist” industry folks, and I have seen scientists who very careful be forced to make really strong statements in opposition.
(analogy below):

As to who reads IPCC reports: yep, most people won’t.
California state water planners do.

Analogy: suppose you feel sick, and 100 doctors come by and measure your temperature, each with their own kind of thermometer.
At first, their measurements range from 98 – 105 degrees F.
Reporter writes: doctors have no idea.

Over time, they improve thermometers, and now their measurements say:
103 degrees, +/-.1, and rising at .1 degree/hour.
They argue incessantly about the +/- .1.
And they all say “Weird form for heat stroke, we really need to stick you in an ice bath, or you’ll be in trouble in a couple days.”
Reporter writes: doctors worry about patient, but still don’t agree.

However, throughout all of this, a physicist who will call FS(not a physician) looks at you (without thermometer of any sort) and says (but never writes peer-reviewede research reports):

You look fine, temperature is 98.6, and is actually going down.
Then
Well, you look fine, temperature is 98.6.
Then
Well, temperatures have gone up and down.
Then
Well, if your temperature goes up, actually, that will be better for you.
and
In any case, there’s nothing we can do about it, and if we did, you’d lose a lot of money, so you shouldn’t. In any case, if you do get warmer, you can migrate to Alaska.

Reporter writes: “Doctors say patient in trouble, but on the other hand, it;s an unsettled issue, as FS says there is no problem.”

In the real-world case, the patient has not yet died, fortunately, nor is likely to, but may well get very sick for a few hundred years. The initials FS are not chosen randomly.

If I may, I’ve got a couple of questions regarding your five points:

1) I know that carbon dioxide levels are at their highest levels for a long time through ice cores and things, but how do we know about the actual rate of warming is higher (temperature is higher)? I’ve read Gerald North’s submission to the US Senate about global surface temperature reconstructions, and this said that surface temperatures in the late 20th century were at their highest levels for 800 years or so. Going back earlier than 800 years, we aren’t so sure.

2) This point is, I’m guessing, based on climate models and the inability to simulate the 1900 – 2000 temperature change without including human emissions. Isn’t there still the difficulty that we have a limited set of data to test these models?

3) I really hate to do this, but going on Karl Popper’s falsifiability idea, Newton’s and Einstein’s theories can be readily tested to check their correctness. You can do the same with climate models, but this goes back to the earlier point, there is only a limited set of data to do this. I’ve read that it isn’t actually to difficult to construct a model that produces reasonable results, this despite the complexity of the climate system. What test would show that these models are incorrect?

My own feeling is that our best guess using climate models etc. is that humans are causing climate change, if not now then probably into the coming years. People like Professor Lindzen are probably just unhappy in the way the science is presented as being absolutely cut-and-dry. On balance, I think the critics of global warming alarmism have, in many ways, just reacted to counterbalance some of the other side of the argument – things like the Greenland ice sheet melting. When scientists say things like this, they should make it absolutely clear that our knowledge of the risks are still very uncertain. Indeed, this is probably what the author will say in their published scientific journal.

In the end, I think that it is not surprising that climate change is presented in such dramatic terms, either the as end of the World or as a great swindle. These things are more likely to catch our attention and this is what newspaper editors and TV producers want. Virtually all of the arguments like the uncertainty regarding aerosols etc, are in the IPCC report, but the average person is not interested in what Professor Wunch is after, that is a cool and reasoned debate. That is far less interesting than a sensational TV programme. I was able to watch the David Attenborough’s BBC programme and the Channel 4 programme all the way through. I downloaded the IPCC 2001 report ages ago but still haven’t read it all. How many people actually will?

The general answer is that the scientific evidence is overwhelming that:
1) The Earth is warming, and warming faster than seen in recent times (where “recent” includes at least the last few hundred thousand years, i.e., several ice-age cycles., to stay within the current orbital regime and tectonic plate arrangement. If you go many millions of years, you can find very different conditions.

2) A big chunk of this warming is caused by human behavior.

3) The physics and chemistry is mostly quite well understood.

4) Science works by successive approximations anyway, and requiring perfection is a ridiculous requirement.
Newtonian laws of motion really work pretty well … unless you need to build GPS satellites, in which case Relativity is needed. Of course, everyone would love to find the model that subsumes Relativity and quantum mechanics, but that has not yet appeared. [I.e., Relativity theories are not complete theories of everything.]
Thus, people think they have calibrated most of the processes, and offer error bars to bound the uncertainty. Over time, the error bars tend to shrink. There are still some issues about aerosols or clouds, but when people say the science is settled, it doesn’t mean everything is known, or that models are perfect, or that there still aren’t a few fuzzy spots. However, as I’ve followed this for years, I ‘ve seen the fuzzy spots shrink, and contradictions get ironed out [as between satellites and ground stations].

Note that economics is not exactly the same kind of science as physics, and I haven’t heard anyone saying the economics are settled.

I would note, that despite disagreements with Bjorn Lomborg on many issues, the ideas that one should do reasoned economic analyses and allocate resources appropriately are absolutely fine. On the other hand, I’m not sure economics deals very well with long-term issues that may have really serious consequences, sometimes simple present-value calculations don’t make sense if you end up with something really costs a lot to fix.

It is also absolutely clear that some mitigation efforts are really low-cost, or actually make money rather than costing it, especially if they’re done sensibly, and early, and not in alarmist fashions. For example, as a tiny example, replacing incandescent lights, where practical, with compact fluorescents, as the older bulbs die, saves money.
Some efforts *will* cost money, but there is plenty of low-hanging fruit in various conservation efforts (which of course some people do not want any of).

At this point, temperature rise seems inevitable, for at least a few hundred years. At some point, after we’ve burnt most of the oil&gas, and lots of coal, and population has presumably stabilized, the temperature will start going back down towards its natural state (in current orbital setup, kilometers of ice over Stockholm), but the heat spike will probably only last a few hundred years. Good things are those that:
a) Reduce the rate of climb.
b) Reduce the height of the peak.
c) Reduce the time spent at the peak [the longer we're there, the more of Greenland melts.]
d) Avoid serious wars over resources, like water.

In the US, states vary wildly in their approach to regulation of:
- pollution
- gas mileage
- energy efficiency

Clearly, any state that is really aggressive in such areas must be a financial disaster, an economic basket-case! Doing anything about energy use will be the end. People will be miserable, it will be terrible …

Well, actually given that one of the most aggressive states is *California*:
http://en.wikipedia.org/wiki/Economy_of_California
1) California is a leader in low energy/person and energy/$ GDP; of course, some of that is the mild weather, but …
2) Per capita residential usage of electricity has stayed flat for several decades, and natural gas has declined slightly.

In any case, this hasn’t happened because anyone waved a magic wand, but because of attention of a myriad of little details over decades [and global warming is similar, no magic wand]. Of course, some California efforts have been really “annoying” to others, like insisting on pollution controls, energy efficient appliances, and better gas mileage.

Of course, lately, serious Venture Capitalists around Silicon Valley are investing big-time in technologies to help energy efficiency … for the same reasons as Jeff Immelt is driving General Electric in that direction.

But why do people in California worry? [The Wall Street Journal Editorial page frequently mocks California for being crazy ... well, sometimes, we are ... but...]

0) California typically sends about $50B/year more to the Federal government than it gets back. That’s about 20-25% of the total (of states that have negative balance of payments like this). Put another way, the CA economy actually matters and it ought to matter more to Washington DC – Maryland and Virginia are major beneficiaries of this.]

1) About 50% of the US fruits and vegetables are grown here. 95% of US wine exports come from here … but, it’s in a rather fragile place.

2) A big chunk of our water supply comes from melting of mountain snowpack.
For those whose water supply does not work this way:
a) Most of the state only gets precipitation only during about half the year.
b) A lot falls in the mountains, where it builds up as snowpack, and then slowly melts.

When we get a warm year, more of the water falls as rain, not snow, and then the snow melts faster. This is not only irksome for the skiing business in the Sierras [big article in Wall Street Journal today about ski areas going very green], but means that we get big floods in the Spring, and then big drought in the summer … both of which are seriously expensive. The 1997 flood was a nightmare.

Oregon & Washington have similar issues to some extent or other, and so do India & China [Himalyan snowpack].
I have no idea how well the general economics analyses actually account for this stuff.

By the way, a big chunk of the California Delta is *already* below sea level, so taht sea-level rise is not a joke here:

http://pubs.usgs.gov/fs/1999/fs175-99/
hurt some, and help others [Like the Loch Ness Winery in Scotland, expected by Richard Selley in "The Winelands of Britain" in a hundred years or so.]

Anyway, thoughtful people in many places (not just California) already take these economic issues very seriously, although as Richard Armour wrote:

So leap with joy, be blithe and gay
Or weep, my friends, with sorrow.
What California is today,
The rest will be tomorrow.

I remember hearing a Professor from Imperial College London on Newsnight saying that those who speak of ‘global warming alarmism’ do so because of their own political views, and that their arguments are not objective. My feeling from various things I’ve read, including the House of Lords report on the economics of climate change and the evidence presented by the expert witnesses, is that there still is a degree of subjectivity involved in the climate assessments. There were respectable economists, like Prof. Richard Tol, Dr Dieter Helm, and Prof. Dennis Anderson, who said things like ‘the economics are different depending on which economist you ask’, and that ‘top economists no longer follow the work of the IPCC’, and ‘the IPCC has become politicised’.

I know that the Royal Society has published a document which attempts to disspel these arguments, but looking at the testimony, I get the impression that there is something in these arguments. Professor Tol explains that some countries (Germany, I think) are now only sending representatives to the IPCC from the Green Party. Some of the economics has been influenced by political decisions. It is not unusual in economics to assign different values for human life depending on the person’s wealth, but this was not allowed in the IPCC. This apparently was because some countries objected to their citizens being valued less than those in other countries.

Another example of the uncertainty in the economics is the enormous differences in the values given for the social cost of carbon per tonne, presumably the value it is given depends on the economist doing the particular assessment. Professor Anderson, if I remember correctly, states that it is probably true that most economists are sceptical about climate change, this because the benefits of reducing carbon emissions are so uncertain.

William Ruddiman: Plows, Plagues, and Petroleum: How Humans Took Control of Climate, 2005. About 10 pounds on Amazon.
http://www.amazon.co.uk/Plows-Plagues-Petroleum-Control-Climate/dp/0691121648/ref=pd_ka_2/202-8778128-8055066?ie=UTF8&s=books&qid=1174369178&sr=8-2

It’s a really fine example of good scientific detective work, well explained, by a well-respected scientist.

http://badscience.net/forum/viewtopic.php?t=2024&start=120

Gotcha!

“So – Wunsch doesn’t think that ‘the edited interview matches his known views” and neither do I – so your assertion is incorrect..”

“Proof” for Dean is not consistent and coherent argument, but his feelings and emotions. His appraoch is only marginally more sophisticated than repeating “I think you’re wrong”… “I think you’re wrong”… “I think you’re wrong”… He simply doesn’t beleive that he has to explain himself; just *expressing* himself is enough.

I gave my opinion on such issues way back at comment #24. The film accurately reported one of Wunsch’s findings, but the filmmakers disagree with him about the implications of that finding. To do so is not bad science, even if it’s wrong.

Carl Wunsch:

“It is probably true that most scientists would assign a very high probability that human-induced change is already strongly present in the climate system, while at the same time agreeing that clear-cut proof is not now available and may not be available for a long-time to come, if ever.”

yet…

http://scienceblogs.com/stoat/2007/03/spot_the_difference.php

Not according to Wunsch – only only a swivel eyed denialist could read his response and think his position had been fairly represented. Maybe he should have realised that Channel 4 ditched their integrity ages ago – but then maybe he doesn’t watch the channel that brought you McKeith and Celeb big brother.

http://www.realclimate.org/index.php/archives/2007/03/swindled-carl-wunsch-responds/

This is specifically what Wunsch had to say about how Durkin twisted what he had to say:

“In the part of the “Swindle” film where I am describing the fact that the ocean tends to expel carbon dioxide where it is warm, and to absorb it where it is cold, my intent was to explain that warming the ocean could be dangerous—because it is such a gigantic reservoir of carbon. By its placement in the film, it appears that I am saying that since carbon dioxide exists in the ocean in such large quantities, human influence must not be very important — diametrically opposite to the point I was making — which is that global warming is both real and threatening in many different ways, some unexpected.”

So – Wunsch doesn’t think that ‘the edited interview matches his known views” and neither do I – so your assertion is incorrect..

“The Independent Television Commission ruled: “Comparison of the unedited and edited transcripts confirmed that the editing of the interviews with [the environmentalists who contributed] had indeed distorted or misrepresented their known views. It was also found that the production company had misled them… as to the format, subject matter and purpose of these programs.” Etc.”

- perhaps something about faking graphs and awarding contributors grand sounding distinctions they didn’t earn…

and then tell Ch4 to come up with another grovelling apology…