Live Blogging Gill on Global Warming

Today the Utah Valley Sierra Forum will host BYU climatologist Richard Gill at the Provo Library. The talk is called ‘Global Warming: Fact or Fiction?

I will be live blogging this event at 7:00 PM MST so be ready for a good discussion. (If for some reason I can’t get internet access, I’ll post my notes later that evening.)

Ok, we are live. (Note I’m not going to pay attention to spelling or grammar in the interest of keeping the experience going!)

Dr. Gill received his Ph.D, from Colorado State and came to us at BYU from Washington State. His office is two doors down from mine and he is breathtakingly smart and wonderfully nice. He is a popular teacher and does a and incredible job of explaining complex topics. What follows is my interpretation of his presentation and will suffer the usual problems of translation compounded by my never having done this before.

Global Warming Fact or Fiction

There is a crowd of about 75 the room holds about 100 and people are still filtering in.

Meeting open. Talking about rock quarry in Rock Canyon. Needs to stop.

Gill takes the floor. Show of hands who believe in GW is natural about 80% raise hands. 15% human caused. %5 think Hoax.

Where is understanding of human climate interactions. He is an ecosystem ecology. Three years at Duke working on climate.

Tells story about inuit village that has been affected. Ice forming later, melting earlier, lost 30% of island due to storm surge. Village had to be moved.

What is the role of science. Science should be an adversarial system. Skepticism is good, but we need to continually return to data.

How many think we are having. We are .02 of a percentage of being normal.

Here is a plot of Provo average:

Weather is not the scale to talk about climate change.

We know C02 affects atmosphere this is not a debate.

Svante Arrhenius thought that humans could not affect climate change.

Three ways to be skeptical:

Climate is not changing in unusual ways.

Climate is changing but impacts are small and possible positive.

Climate is changing in harmful ways.

Climate From ice core data we see that C02 follows temperature.

Warming period from 140 until 2007, 2008 was a cooler year. What is the proper scale to look at with climate. There is lots of variation. We must be careful how we interpret data. Or do we look at broader trend.

Parts of globe are much warmer (polar regions) others are cooler.

How else can we look at this. Geologists have been measuring and see the crust is warming from top down.

Glaciers are retreating globally. Northern migration of species.

How do we attribute this to humans?

Are changes consistent with models of change.

Radiative Forcing: If you look at expectation from atmosphere changes in Atmospheric gases. We expect a 1.63 change. If warming was from solar cycles you would see certain signatures, most dramatic would be in night time warming, Tropospheric warming. if gases you see other signatures. We see the gases signature.

Models that model past data project into the future do well. To get the outcomes we see is only explainable by human additions having an impact. Many models tell the same story.

The future under models:


In Rocky Mountains based on climate change slightly wetter but about 3 degrees hotter.

Palmer drought index. Two drougts one in 50’s we just came out of the last one.

2006-2030 Drought will be like it was between 2000-2003, because of hotter temperatures. Much less water for hydropower, crops, and biodiversity.

Model results:


World wide effects may destabilize countries. Urban settings may be worse.

Public Health: disease specific some places may gain Malaria others lose it.

The amount of Carbon in the atmosphere can go into sinks to store more carbon: Ocean, trees, & soil.

His own research is on this. He has grown trees in chambers with different gradients of CO2. So they can look at CO2 in different periods of the Earth (interglacial and such). Research says soil sinks may be full.

Also worked on Duke Free-Air Carbon Dioxide Enrichment. Bathe a forest area in CO2 to levels we expect 100 years from now. Trees grow better at first but absorption is limited.

Personal Choices (low lying fruit): Personal choices (use less energy).

Innovated Public Private Partnerships. Cities use 75% of Energy. Growing green markets. Right now things like Hybrid Buses are very expensive, too much for a city, but multiple cities, combining efforts drove price down. Example, Seattle & Chicago work together made it possible.

Becoming more efficient allows us to be free of control by oil producers.

Action will be very hard. Fundamental changes in technology of energy generation are needed.

Impediments: We use 1920 infrastructure for moving energy around.


We need innovations to store energy more efficiently and more affordable so windmills can store energy when wind is not blowing.

Policy Innovations. Democrats and Republicans have joined efforts.

Bad Ideas: Ethanol. It takes 70 years of growing corns to become carbon neutral. Net effect negative.

Realities: Hard, but old technologies need replacement. Innovation. Market forces.

Today’s Choices Have Consequences:

If we take action world will be warmer but not as warm as if we do nothing. Choices we make in policy and personal actions will make a difference.

End talk. Questions:
Audience: Models are not useful it’s all based on models.

Gill: Alternative is to do nothing. Or do we bring together our best physicists, science and use our best thinking and quantitate tools.

The scientists involved are not arguing about the models they are arguing the about the magnitude of change.

Q: Are the loss of trees in South America increasing rate of change.

Gill: Buffers give us time.

Q: What was the the atmosphere like in Carboniferous and wasn’t that higher.

Gill: Much warmer in the past. Temperature varies 15 degrees in geologic time, but never have we seen a degree change in a century.

Q: Why isn’t water more important in these calculations. Water is the major Green House Gas. To say that temperature isn’t influenced by sun is not right.

Gill: We can’t control water. This is taken into account in the models.

Q: What will Utah look like when there is seven degree change.

Gill: Skiing will go down. Winter recreation will slide. Rain fed Ag. impossible.

Q: Carbon can only increase temperature so much 1.6 degrees, why are we worried.

Gill: As CO2 increases, water vapor increases, which is the most important green house gas.

Q: Way to complex question on absorption bands in water. Water swamps everything.

Gill: Water in upper troposphere disappears and that’s where green house maters.

Q: Radioactive decay is what makes life possible any affect on temperature.

Gill: No.

Q: Has water vapor increased in Last 100 years.

Gill: No. But there is much local variation. Some local climates dominate.

Q: Senator from Oklahoma lists studies and individuals who disagree with IPC report on climate change.

Gill: Skepticism is not bad. Debate is good, but most of these were not in the field. Other have asked to have name removed. But open debate is good.

Q: What about cow methane? Isn’t that a contributer.

Gill: Rice more significant source, but it is a source.

Q: Could you summarize.

Gill: Two minute version. Climate is warming. We can calculate a probability to the chance it is human caused, that is 90% chance it is human caused. This is dominated by industrial nations. Could it be a hoax? The way science is done a hoax would be hard to maintain in the way science operates. If someone can debunk it they would be famous. The current climate of science this would be impossible to maintain.

Q: What is your take on future of humanity?

Gill: I am optimistic. We have become to politicized about this. Science should supersede the politics.

Q: Given the scientific consensus isn’t it up to the skeptics to deal with the data and make their case? Isn’t this a sign that it is based on ideology.

Gill: We need to ask the skeptics to use the same tools we use. To produce the models that make their case. They have not dealt with the data in the same vigorous way. He welcomes the skeptics to do this.

Q: Temperature plot between 1940 and 1950. I was a senior in high school the climatologists were predicting an ice age based on the dip.

Gill: It is a myth that climatologists were arguing this (or very few where) but there was debate then. We have more extensive data and methods. But we can have fun. Why was there warming during World War II? It might be the way they took temperatures it may be an artifact but who knows. But coal and aerosols burned and so the flat part prior to 1960 may have been cooling by these, then in 1970 clean air act let the global warming continue.

Q: How good are the models today?

Gill: They are extraordinary and sometimes run for weeks and even months. How are model tested? By modelers are given blind data. Many modelers working independently get same answer. No model, across many modelers, has not seen this warming.

Moderator: Has anyone’s mind been changed? No not really.

The End.


  1. Any hecklers?

  2. So if we do nothing the oceans might rise about 21 inches a century from now. Is the possibility of reducing that rise to 14 inches worth tripling the real price of gasoline, natural gas, and electricity for?

    It is also worth noting that there hasn’t been a net rise in global temperatures for almost a decade now, and further more that CO2 levels may not be the primary contributor to global warming in any case. Milankovitch cycle q.v.

  3. How are you getting these graphics? Taking pics of the screen and uploading on the fly?

  4. What is his conclusion about how much impact we can have – and the long-term effects of what we can do?

  5. Nice.

  6. Steve Evans says:

    Nice one about the decline of Utah winter recreation.

  7. Mark–sea level rise is only one of many likely climate impacts. We’re also likely to loose a lot of cropland that’s currently under cultivation to increasing aridity.

  8. Mark Brown says:

    Good job Steve.

    This was interesting and informative. Thanks.

  9. Ok, I am a climate Luddite, but I was wondering if you genius types could explain if the ozone hole thing I was taught aerosol cans made when I was a kid is related or not?

  10. Matt W–no, ozone has nothing to do with global warming. Neither ozone or CFC’s (the compounds that break apart ozone) are significant greenhouse gases, mostly because they just don’t absorb infrared radiation. Greenhouse gases, including CO2 and methane, absorb in the infrared, and so trap heat in the atmosphere.

  11. I hope everybody interested in this topic has read SteveP’s great blog post on the topic. (It also, incidentally, gives an example of a climate-change problem not directly tied to rising sea levels.)

  12. I am not an expert, but according to wikipedia:

    “Although ozone was present at ground level before the Industrial Revolution, peak concentrations are now far higher than the pre-industrial levels, and even background concentrations well away from sources of pollution are substantially higher.[20][21] This increase in ozone is of further concern because ozone present in the upper troposphere acts as a greenhouse gas, absorbing some of the infrared energy emitted by the earth. Quantifying the greenhouse gas potency of ozone is difficult because it is not present in uniform concentrations across the globe. However, the scientific review on the climate change (the IPCC Third Assessment Report[22]) suggests that the radiative forcing of tropospheric ozone is about 25% that of carbon dioxide.”

    So it is not negligible, but usually when people talk about the ozone hole they are talking about stratospheric ozone.

    But the story of the ozone layer is relevant in that it was an example of international cooperation where governments listened to experts, took them seriously, and quickly acted:

    “It is believed that if the international agreement is adhered to, the ozone layer is expected to recover by 2050. Due to its widespread adoption and implementation it has been hailed as an example of exceptional international co-operation with Kofi Annan quoted as saying that “perhaps the single most successful international agreement to date has been the Montreal Protocol”.[1]”

    Unfortunately, political leadership on climate change has been comparatively a disaster. It’s depressing that 85% of the audience at the Provo library could listen to the expert address each of their concerns and that they all would simply choose not to believe him. Even more depressing that we had a government for eight years whose contempt for science and expertise was, if possible, even greater.

  13. Aaron Brown says:

    “Moderator: Has anyone’s mind been changed? No not really”

    Did the moderator actually poll the audience at the end? I assume that’s what this means.


  14. Thanks, Steve. Can you answer my #4? It is a serious question.

  15. Thanks, Steve.

  16. #3, He gave me the graphics on a key drive before the lecture started

    Ray, Yes he talked about what needed to be done, but the answers are not very easy. He pointed out that there are little changes that we can make in our lives that will help a little, he called this the low hanging fruit. But he also pointed out that there are real challenges ahead. To really be effective though its going to take refocusing on developing new technologies, getting governments to work together. One recommendation I would make that gives very informed diagnosis of the social, political and economic problems that need to be addressed is Thomas Friedman’s book Hot, Flat, and Crowded. He puts out very optimistic ideas on how businesses and economies can be restructured for a greener and more productive world. He sees he restructuring of technologies as the biggest opportunity in the last century and he gives lots of examples.

    #13 Yea, he asked at the end. Everyone was more enlightened I think, but my feeling is the denyers have never been interested in the data as such so how could their minds be changed by it? Gill made a great point that I think needs more attention. The projections come from complex simulation models, which are easy to criticize, but multiple modelers working on different models come to the same results. This is called robustness in the modeling world because it means that multiple teams coming from independent approaches all see the same thing when they input the data into the model. This is a big deal. The thing about the denyers is they are free to do the same. Come up with a model that all agree have taken into account all the processes and put it on the table for evidence. They never do.

    Mark D. The Milankovitch cycle, is well understood, incorporated into the models and does not explain the variation we see in climate.

  17. One recommendation I would make that gives very informed diagnosis of the social, political and economic problems that need to be addressed is Thomas Friedman’s book Hot, Flat, and Crowded.

    YES!! i also like Lester Brown’s book Plan B 3.0. Both books will not make you warm and fuzzy, though.

    Everyone was more enlightened I think, but my feeling is the denyers have never been interested in the data as such so how could their minds be changed by it?

    so why would they go and listen to gill?

    I’m still stuck there.

  18. #17 “so why would they go and listen to gill?”

    To stop the hoax! It’s spreading.

  19. mfranti,

    I think SteveP already established why: “he is breathtakingly smart and wonderfully nice”. ;-)

    Actually he is. He was in our ward up here in Washington for several years before moving to Provo last year. Brilliant researcher, super-nice guy.

  20. Thanks for the live-blogging Steve. I wonder if we could change the attitudes the audience displayed here (which I am hoping are not representative) by emphasizing our religious mandates to be stewards of the earth? I heard that there has been an upswing in the number of Evangelicals who are also environmentalists.

  21. Bill–Ozone is not a significant greenhouse gas. If its forcing is 25% of that of CO2 and its concentration is 1000 times smaller, its impact is not going to be very large, especially compared to CO2 and methane.

  22. If we continue to introduce growing amounts of greenhouse gases into the environment we risk a set of disruptive and potentially catastrophic consequences for humanity, including all sorts of plagues, wars, and natural disasters.

    If we mess up the economy trying to stop putting growing amounts of greenhouse gases into the environment we risk a second set of disruptive and potentially catastrophic consequences for humanity, including all sorts of plagues, wars, and natural disasters.

    No one can say which set is worse or more likely at this point because our ability to model socio-politico-economic systems is far less than the ability to model the climate, let alone how they interact with each other as either changes rapidly.

    For example, World War II grew directly out of a collapse of economic activity, and the planet’s ecology would not like a World War III. Yet, the numbers don’t permit sufficient reductions in greenhouse emissions fast enough to stop major climate changes without short term economic consequences few if any political systems could tolerate (see Iceland, used to be).

    There is legitimate question, in other words, whether we are already caught between a rock and a hard place. Maybe our tradition really needs to focus on the contribution we make by being “prophetic people” who can lend the hope of obedience of personal revelation in wise lifestyle choices.

  23. Richard Gill was oddly dismissive of the person who complained that you “can’t trust models.”

    On the one hand, he’s right that models are all we have. On the other hand, it’s absurd to suggest that these models give us something like “90% certainty.” Read the IPCC reports and even there you’ll see that there are possibly-huge factors that are poorly understood or just left out.

    He’s also right that the critics need to compete by providing competing models. But I strongly suspect that they would have a hard time publishing things because the whole issue has become political. That kind of thing happens in academics all the time.

    There’s not much doubt that there has been a warming trend, and there is no real doubt that CO2 is increasing due to human actions. But simply don’t believe that we have a good idea about how large the effects will be.

    Furthermore, there are lots of other factors that cause the climate to vary that we also don’t understand…for example, such a large factor as the Pacific Decadal Oscillation was completely unknown at the time of the second IPCC report, yet that report expressed the same kind of confidence and certainty that we see in the current report!

  24. Rameumptom says:

    While I believe there is global warming, and that we may be producing some of it, I’m not convinced that it is as bad as many think.
    History shows in previous periods that global cooling has had worse effects than warming overall. Yes, there may be some places that are adversely affected by warming, but nothing near a cooling period.

    The last Ice Age wiped out many species, including human-like species. During the little Ice Age around 1300 AD, the black plague wiped out 1/3 of Europe, destroyed the Viking settlements in Greenland and Americas, and caused droughts and starvation in many places.

    After the last major Ice Age, world populations exploded. Before and after the little Ice Age, world exploration greatly increased, England grew grapes for wine as good as France’s, the Renaissance was accomplished because enough wealth was created to allow people to move beyond subsistent living.

    France’s history of royals was destroyed by a cooling period, which caused hunger throughout the nation, and caused the mobocracy that led to the French Revolution.

    So, I’m guessing that slightly warmer climates may not be as tragic as some insist.

    How do we cool the earth? Some scientists suggest jettisoning pollutants into the atmosphere to reflect heat back into space. This is probably the cheapest and easiest way to actually maintain/cool the planet. And it does not require us to cut back on fossil fuels (although I am a proponent of alternative green fuels to protect other aspects of the environment).

    Sadly, now is the perfect time for Pres Obama to announce a “mission to the moon” effort to transform our energy grid, but he is too focused on other issues (like shooting pirates – just why did the Navy Captain need Pres Obama’s permission, anyway????). The grid does need to be updated. Now.

    We also need to have radical environmentalism put in its place. They are actually suing against green energy. While companies attempt to build wind mills, the environmental wackos are suing, because the power lines will affect the environment! Oh, and Ted Kennedy won’t allow windmills off the coast of his estate, because it ruins the view. In California, they cannot build solar power in the desert, because it will affect tortoises.

    We won’t get the new power grid and alternative energies, simply because the far left won’t allow them to be built.

  25. It’s sad to see Gill and SteveP make lucid arguments and then have them answered here by inconsistent rightwing boilerplate that don’t even address the scientists’ contentions.

  26. It’s pretty clear to me that the scientists like StevenP and Richard Gill are doing great work studying these issues, especially when they concentrate on their areas of specialty.

    But it is also clear to me that the politicians (Al Gore and his ilk) have taken bits and pieces of individual evidence to pursue policy prescriptions (ie Ethanol) that pursue their own political objectives, to the detriment of the world as a whole. In addition, Al Gore and his ilk are doing no good for the field of science by exaggerating the threat of global warming, which is something Al Gore himself has admitted he does in an attempt to influence the debate (or more accurately, to shut down debate — Al Gore famously refusing to debate anyone on this issue). So when global warming skeptics like myself continue to think the whole thing is an exaggeration (as I become more convinced it is every day), I hope it is clear to StevenP that such skepticism is not aimed at the honest scientists but instead the dishonest politicians.

    StevenP, I have been studying this issue as a layman for several decades, and I remain convinced that global warming will go away on its own regardless of what we humans do and 20 years from now we will be worrying about some other environmental “threat” that is about to destroy the world. It is also worth pointing out that if you study the big picture, the best thing you can do for the environment, if that is really your concern, is to encourage technological development, because that is what cleans up the world. (A few small examples: 250 years ago, the biggest environmental threat to the East Coast of the United States was the lack of trees because they were all being cleared to make farms — now there is the greatest amount of forest cover on the East Coast in 300 years. 120 years ago, the greatest environmental threats to big cities were coal smoke and horse manure — electricity and the automobile took care of those concerns.)

    So, to the extent that global warming hysteria stops technological development, it is certain to worsen the environment, not improve it.

  27. Mark D, #2, below is a quote about a plan to deal with the rising sea level. He claims his solution will keep the sea level from rising, and also produce electricity and more farmland.

    “His plan is to channel seawater via one or more canals from the Mediterranean Sea to a section of the Sahara Desert that is ringed by mountains (which is below sea level). It is located in western Egypt near the Libyan border.

    Hydroelectric power plants along the canals will harness vast amounts of clean energy as the seawater flows into the land-locked sea. This power supply will create an economic stimulus for poverty-plagued Egypt and its North African neighbors. And, perhaps most exciting, it can be used to desalinate some of the sea water to cultivate parts of the Sahara, turning it into productive farm land.

    Dominic’s vision, detailed in his paper “Plan to Manage Sea Level Rise to Save Our World from Flooding,” should be shared worldwide. All nations, except the land-locked few, should be eager to help fund the construction of this massive project. The cost, though large, is estimated to be less than what the US has already spent on the Iraq War.”

  28. Case in point.

  29. Sorry. My #28 was in response to #26.

  30. I think it would be fun to live blog the actual global warming – not just a talk about global warming. It could be fun…

    – It’s getting warm.
    – Okay, it’s really kind of hot now.
    – The north pole just melted. LOL
    – Oh crap, the ocean is coming in my window now.
    – PFOS (parent floating over shoulder)
    – Do you think dirt will really be valuable like it was in the movie Waterworld?
    – Do you think the DVD of Joe Dirt will be valuable.
    – Okay, drowning in the boiling ocean now. Later.

  31. It is sad to see commenters like Jeremy make sweeping generalizations about comments without actually having read them.

  32. Kristine N: Thank you! You answered my question. I didn’t understand most of the words, but the general idea is “No they aren’t really related” , I think.

  33. William H. says:

    re: 7


    Will we gain any cropland through rising temps? If so, how much?

  34. Matt W–you’re welcome! That’s all I was trying to say. The ozone hole was caused by emissions of a different group of gases that don’t impact global warming and the ozone hole didn’t impact the Earth’s temperature. I hear that question a lot, actually.

  35. William H–I have no idea about numbers, though I can look and will get back to you.

    So, really what will happen is most of the cropland we have now will become unsuitable for the crops we’re currently growing on them. I think I remember hearing there was recently a revision of the plant hardiness zones map to reflect observed changes in the length of seasons. The plant hardiness zones are shifting to higher latitudes and elevations. So, if you wanted to grow more corn in Canada, sure, we’re going to gain cropland there. At the same time, we’re going to loose some cropland in the midwest as it becomes to hot and dry to grow the stuff we’re growing there currently. Off the top of my head I’m not sure how those will balance out, either for the US or for the whole world.

  36. William H. says:


    Is it possible that the world could actually gain more cropland than it loses?

  37. #23 There are lots of uncertainty in climate change. Let me explain the 90% probability that the climate change we are seeing is climate change. It’s not that we are “90% certain” it’s that after taking into account all known natural processes (and CC skeptics scientists are really not as inept as they seem to be reported to be in the skeptical radio/internet crowd, they do take into account water vapor, sun activity cycles, everything that’s known to affect climate), until you put in human you don’t see the changes we have seen 90/100 times. And this should not be as surprising to people, we know how a green house works. In fact if a bunch of space faring advanced aliens visited the earth 100,000 years and found it just a tad cold the first thing they’d say is, “Hey, the crust if full of hydrocarbons (oil, coal) let’s just burn that and we can get the temperature up about 7 degrees!” It’s what we’d do if we wanted to raise the temperature.

    #24 It may be good for some people, true, but in places like Africa it can be very bad. It’s already bad. Those are some of the big unknowns. In Utah, for example the worlds greatest snow might disappear, but folks in Canada might find some great new agricultural opportunities. New shipping ports may open connecting Russia and Japan. There are lots of unknowns. But most of the anticipated changes are harmful for most people especially coastal cities, developing countries, urban centers, etc. A few months ago an article in the Atlantic by an ex-global warming skeptic economist (can you parse that?) went over the winners and losers. Yes, there are winners. More losers. More political instability. Also, the losers are species that cannot adjust to the speed of the changes. As Gill points out when you look at the last 800,000 years, there has never been a degree change in temperatures in a Century as we have seen. That’s outside of many species response.

    For me this is more of an ethical issue. it may be that we will never have any certainty on this. But the potential is more toward disaster than good. If a doctor said to someone, “I’m withholding treatment because there is still a 10% you don’t have a disease, and well, we need to wait until we are a little more certain before we act!” you would find a new doctor. And well, if there is a 90% chance that my grandkids are going have a really hard time of it, I ought to act now. We need to bear these costs, not push it on them, just because we are not quite sure.

  38. William H,

    It’s possible, but I’m not sure it’s really the right question to ask. If Canada gains a bunch of cropland that more than makes up for cropland lost in China that’s not a very good situation to find ourselves in.

  39. Also, ya’ll might find this interesting. In it 97% of people working on climate research believe it is human caused. Only 50% of the general public do. Part of the problem is that the press, trying to appear to give balance, interview the 3% often to appear fair. The truth is people working in the area are overwhelmingly convinced that climate change is human caused.

  40. In by brief perusal of the literature on global warming and cropland it looks like the scholars who think global warming will be good for agriculture assume there’ll be plenty of water, while those who factor in likely impacts of global warming on the hydrologic cycle think it’ll be detrimental to agriculture.

  41. Kristine N, thanks for weighing in too, you have brought a lot of insight to several of these questions! I agree. And I think there will be regional differences. Right now the effects in Africa have been bad.

  42. Part of the problem is that the press, trying to appear to give balance, interview the 3% often to appear fair.

    Right. I think your analysis of the media’s role is spot on. On an issue like this, where one side is by almost all good measures simply wrong, you can’t be simultaneously “fair and balanced.” At some point, it is time to quit debating whether or not we have a problem and to move forward with solutions.

  43. SteveP–Thanks for blogging it! It sounds like it was a good talk and brought up some important issues. From your blog post on tetse flies it sounds like the impacts of global warming in Africa have been pretty bad–and are likely to get worse. That’s probably the worst aspect in my mind about global warming–we first world nations have created what will likely be a terribly damaging situation, but we won’t feel the worst of the effects.

  44. Thanks for the Science Daily article, SteveP.

    Wow, 97% There has to be a point, where “skepticism” becomes “hubris,” right?

  45. “And this should not be as surprising to people, we know how a green house works. ”

    SteveP, this is simply misleading. The direct “greenhouse” mechanism is not in dispute. But the majority of the predicted warming is not due to the direct effect, but due to supposed positive feedback effects that include things like water vapor and clouds that are very difficult to model accurately. Wouldn’t you agree?

  46. ed–no.

  47. Kristine, can you tell me what part you don’t agree with? I thought what I wrote was a pretty accurate description of the situation…what am I missing?

  48. SteveP, This was interesting, thanks. I’m currently reading Lomborg’s The Skeptical Environmentalist. Do you have an opinion of that book?

  49. ed, everything is difficult to model :) It is a complex mix of direct effects and feedbacks. But the modelers are doing a good job of capturing the complexity.

    Jacob J, Awful book. Does the equivalent of saying there is no such thing as poverty because mean income in the world has increased. It’s become sort of a textbook example in statistics programs of how not to do an analyses. Read almost any review from a science or technical journal and you’ll see what I mean. It’s universally vilified. (Although, CC denyers embrace it as a standard work).

  50. Geoff B: I hope it is clear to StevenP that such skepticism is not aimed at the honest scientists but instead the dishonest politicians.

    Is there an agreed upon theory among skeptics about what the motivation for this alleged dishonesty about the severity of the global warming problem is? Are people saying that it is a case of Chicken Little or some massive coordinated left-wing conspiracy to do something liberal-ish to us all or something else?

  51. Geoff, Actually it’s hard to understand. I think the kindest way to read it is that they think scientists are so inbred they aren’t looking at alternatives. There are those who smell conspiracy. Both misunderstand how science works. Science is a bloodthirsty free-for-all. The best way to advance your career is to knock someone else’s theory into the dirt and stomp on it. Consensus is hard won in science. If someone could show that the models are wrong and demonstrate why they are wrong they would get a lot of attention, fame, and grant money. Now, remember, scientists are subject to all the social influences of any other enterprises: jealousy, blindness, bias, prejudices, mistakes, etc. But its strength is it is always examining itself and its methods, it has rigorous standards of review, it’s always checking itself against the data, and its findings arise in a grand Darwinian struggle for existence as scientists battle it out. When something survives this bloodfest, it’s best to pay some attention to it. And if you disagree, enter the fray, write your own models, and show where the others are wrong. If it’s good work you’ll be famous.

  52. SteveP: “It is a complex mix of direct effects and feedbacks. But the modelers are doing a good job of capturing the complexity. ”

    How do you know this? Are you a modeler? Have the models made any important out-of-sample predictions that you can point to? Can you point to any similarly complex models in any field that have proved to give successful predictions? These are serious questions, not just cheap shots. I really think the central question is how much faith we can put in the models.

    (I hope you will at least admit that it’s not as simple as “we know how a greenhouse works.” )

  53. SteveP: The truth is people working in the area are overwhelmingly convinced that climate change is human caused.

    What percentage of climate change is generally agreed upon as being human caused Steve? Are we responsible for 50% of it? More? Less?

    From what I can tell that is the pressing issue on the minds of the skeptics in this thread.

  54. SteveP: There are those who smell conspiracy.

    Yikes. That is what I was afraid of. So this is led by conspiracy wackos? What do they claim the motivation for the alleged great man-made global-warming hoax might be? (I mean a such a worldwide hoax has to have a motivation of some kind right?)

  55. “If someone could show that the models are wrong and demonstrate why they are wrong they would get a lot of attention, fame, and grant money.”

    Well, as George Box said, all models are wrong, but some are useful.

    Imagine that the warming of the last century was caused mostly by some as-yet-unknown factor. Now suppose somebody puts together a perfectly good model of global climate that incorporates many known effects, but with various simplifications. This model predicts only small warming from CO2 going forward. But this model would also not predict the warming of the past century, since it failed to include the as-yet-unknown factor!

    How easy would it be to get this published? Critics would point out that the model fails to match the observed data over the last century, and they would also be able to selectively complain about any of the huge number of simplifications that are necessary in building any such model. The referees on the paper would likely be people who had models of their own with different modeling choices that made predictions that disagreed with this model. It wouldn’t win anyone any fame or grant money. The results might be impossible to publish. Yet it’s also possible that it would make the best predictions of any model so far.

    What part of this seems far fetched to you?

  56. Satellite measurements show that temperatures have been rising an average of about ~0.16 degrees C. / decade over the last three decades. Temperatures haven’t risen over the last decade but that could well be a temporary anomaly.

    There is no compelling scientific evidence that this temperature increase is largely caused by anthropogenic factors – that is simply the best guess – a guess because over the short term it is essentially untestable. Over the long term, there is significant evidence that carbon dioxide levels lag temperature increases rather than the other way around, i.e. temperature increases cause CO2 level increases not vice versa.

    I mentioned Milankovitch cycles, as an example of solar factor significant enough to take the earth in and out of ice ages. At the moment, we are still coming out of the last one. So over the long run (for the next ten thousand years) global warming is virtually inevitable due to factors we can’t can’t control – global warming which is *much* worse than anybody but Al Gore’s wildest dreams for the next century.

    In the short run, there are other solar factors that may account for global warming and cooling on much shorter scales. The predominant one is the solar wind, which varies with the number of sun spots. There haven’t been a lot of sun spots lately, and that may account for the unusually cold temperatures of the past year or so.

    But the AGW CO2 theory may be right. If current trends continue temperatures might rise (0.16 C / decade * nine decades) = ~1.44 degrees C by the end of the century. So if we pull out all the stops and triple real prices on gasoline, natural gas, and electricity worldwide we might just reduce that increase by a third and be a whole half a degree cooler than otherwise. That doesn’t sound like a a healthy tradeoff to me.

  57. ed, Well, funny you should ask, actually I am a modeler. In fact, I’ve written large simulation models that follow the evolution of insect resistance that are spatially complex, and that follow the ecology, genetics, and management of multiple agricultural fields. Check here for my pubs on this. Perhaps more relevant, I do philosophy of science on simulation models, how they represent, their weaknesses, and strengths. My papers on this are on the same site as above. And my models actually, were used to set US agricultural policy on managing resistance in Cotton and Corn. I made predictions and they’ve born out. In fact, (bragging going into full throttle here), with the simulations I did we saw complex behavior that no one expected, but once seen was perfectly explainable and explained some of the ways resistance to transgenic crops played out. So funny you should ask. I’m really, really knowledgeable about computer simulation models. The CC models are as good as they get. They are under tremendous scrutiny. And are twisted and tested in ways that are rigorous. The way you test and prove these models is to do things like see if you can input data from the past, and see if you can predict the future you do have, (model 1940-1970 and see if you can get the signature of 1971-2007). This is complex and much blood is spilled on how and why to test these models. The other thing that’s telling is how multiple models tell the same story. These models are written by different people, with different assumptions, parameterizations, methods etc. And they get the same results. Philosophers of science call this robustness and it’s used in other simulations that are less controversial (like structural integrity of steel under different stresses or simulating protein formation in molecular processes for example). These things are much more testable than the climate but seem to be successful under the same kinds of testing and procedures as CC models. But you are not incorrect, the models should be challenged, questioned, and put through the ringer. And if anyone comes up with a test they want to put the models though, the modelers would love to try it. They are very interested, as I was, in getting it right. But your questions, ed, are good! and important! A lot of weight is put on these models. But we don’t believe them easily, and they are as good a model as we have for anything. If we abandon them wholesale as a way of knowing we are giving up models in many disciplines and in everything from galaxy formation, to manufacturing processes (to insecticide resistance!). So if they are to be dismissed, let’s dismiss them in the right ways.

  58. “There is no compelling scientific evidence that this temperature increase is largely caused by anthropogenic factors”

    Except all those crazy scientists (97%) who actually study the climate who think there is.

    Mark D. They put all these things into the models. They are not missing all the things you are pointing out. It just does not explain it.

  59. Mark D: So if we pull out all the stops and triple real prices on gasoline, natural gas, and electricity worldwide we might just reduce that increase by a third and be a whole half a degree cooler than otherwise. That doesn’t sound like a a healthy tradeoff to me.

    Ahhh… Maybe Mark has revealed the actual resistance to the global warming findings by all of these scientists. Actually fighting it will cost money.

  60. Geoff, that’s right. This is not going to be easy. But hey our grandchildren will be very grateful that we did something to make their world more livable. That’s why I see this as an ethical choice. We don’t have certainty, but the window of action is closing, and if the predictions are in the ballpark we need to rethink they way we deal with energy. And as Gill said this can be an economic opportunity. It maybe through our choices now our grandchildren will think of fossil fuels as quaint as we do whale oil. It would be nice not giving our money to the big oil nations too.

  61. SteveP, thanks for your reply, that is very interesting!

    To quote from one of your papers:
    “However, complex simulation models can have a role that is different from that of simpler models that are designed to be fit to data. Simulation can be viewed as another kind of experimental system and should be analyzed as such.”

    I totally agree with this! The thing I’m afraid of is that climate modelers are taking complex models that are generally NOT designed to be fit to data, and fitting them to data. You say that they validate the CC models by fixing them so, for example, the 1940-1970 data predicts 1971-2007. But this should always be possible with enough degrees of freedom in the model.

    (BTW, I appreciate the chance to communicate with someone who knows a lot about this. Do you really have much experience with CC models in particular, on which to base your confidence?)

  62. SteveP,

    So I am gathering that the argument is boiling down to disagreement over whether fixing the man-induced portion of the problem will be worth it or not. This brings us back to my question for you in #53. If we halt the man-made additions to global warming how much of a difference will that make? The skeptics seem to be implying we can only slow this proverbial train a little bit anyway. To modify my question a little: What percentage of current climate change do you think is human caused? (This seems to be the crux of the issue… if we all agreed on this percentage we could then decide how much money it would be worth to fix it for our grandchildren’s sake right?)

  63. Thanks ed, No I’ve never done CC models myself, but their testing and development is the subject of much of the discourse about simulation modeling in general that I deal with. They are the kind of modeling that gets the most scrutiny because they are so much in the public eye. The prediction runs I mentioned are just one aspect of the testing. I would say they are as good as it gets. if you don’t trust them, your probably inclined to believe that simulation is inappropriate in any setting. If you’re a Las Vegas odds maker, though, you’d put your money on the model results. It’s not certain they are right, but that’s the way to bet.

  64. Geoff, I’m not sure about the percentage, but I’ll try and find out. But it is known (look at the last graph in the post) that we can seriously make a difference by taking action. The difference between 3 degree change or 6 could make a difference of whether we are skiing in Utah or not.

  65. Great info. Thanks, SteveP.

    Any mention of ocean acidification? For some reason people seem to fixate on the warming/sea level and forget about other related issues.

  66. John Mansfied says:

    Offhand I would guess that a third of the world’s population is living in places that hosted a fairly minor portion of the world’s population a century ago. Global warming or no, I expect the that something comparable will also be the case a century hence.

  67. StevenP, thanks for mentioning -if only briefly- the modeling of stresses in steel (my area of expertise). True, this area of modeling is less controversial than CC, but in other ways it is analogous to CC. For instance, there is no way that the lay public can understand the intricacies and nuance of my models, much less discredit the models. Complex modeling is ummm…complex. I’m just glad that I don’t have to deal with many of those pesky ‘residual stress’ skeptics.

    Were engineering models able to predict the I-35 collapse (and they would have if we had known to look -but that is another story) we would not have sat on our hands and waited to see what might happen. We would have warned of danger and worked to correct the problem. Because they can, I applaud the scientists for standing up and warning us of the CC risk.

    It is frustrating to me that technical information gets watered down and even adulterated by politicians, reporters, and pundits. I like to read that your friend Gill is taking the data directly to the people. He has inspired me to do the same regarding our failing infrastructure.

  68. Thanks! L-d Sus, I’m glad I picked that as an example! And I agree to explain the complexity of these models would be a book length endeavor. It takes many eyes to get them right, and it is too bad they get picked at by people that don’t understand what goes into getting these right. I’m glad you weighed in!

  69. Steve, the problem with back testing is the models are calibrated using the very data they are back tested against. The real test of any model is in its ability to predict unexpected things before they happen. I have yet to hear of any model that successfully predicted that average temperatures would not rise for previous decade.

    Whatever factor accounts for that is at least as strong as any contribution that rising CO2 levels made over the same time period. And yet this factor is either completely unknown to science, or underestimated to the extent that backward testing did not detect it at all.

    Modeling is a useful tool of course, but I find it unusually amusing that you mention a manufacturing simulation in the same breath as a climate simulation. How is the modeling of the internal fluid dynamics of the sun going? Anyone have a clue why the sunspot numbers are unusually low this year? Since when has the effect of the solar wind on cloud formation made it into any climate models? Did anyone know within an order of magnitude how large that effect is until more than a couple of years ago?

  70. SteveP, can you recommend something to read about CC models from the “discourse about simulation modeling” you mentioned? Something on a technical level would be better than something for a general audience.

    “if you don’t trust them, your probably inclined to believe that simulation is inappropriate in any setting.”

    I think simulation can be very useful for learning and building intuition and getting ideas about how effects can interact, what factors can be important, what parts are robust or not, and so forth. As you wrote, it’s like an “experimental system.” But as a method of making forecasts in a complex system I’m more skeptical.

    “they are as good a model as we have for anything.”

    Surely you don’t believe this? You think the model of the global climate is as good as (say) the model of planetary orbits due to gravity? And it’s not even a single model, it’s a set of models that get somewhat different results and are developing all the time. Statements like that just convince me that the modelers are over-confident. (I also wonder how well the steel-stress models would have performed if the modelers had never been able to do any experiments on any steel, since that’s the kind of environment the CC modelers are working in.)

  71. Geoff J, There are always some who are wealthy enough not to care whether their country spends trillions of dollars accomplishing next to nothing. Temperatures probably will go up. Spending all the money in the world is not likely to change that very much.

    There is a cost benefit ratio here. Some of us would prefer that the benefits clearly be shown to outweigh the costs before the government embarks on the largest spending program in history trying to reduce the levels of one of the most benign gases known to man. Personally, I would prefer the government spent its time addressing problems it can do something about, such as avoiding bankruptcy.

  72. avisitor says:

    Skeptics might be justified in remaining skeptical as long as large numbers of people in the scientific community continue to publish papers, hold conventions, and sign petitions like the ones in the link above. The review article’s models and graphs are extremely interesting.

  73. avisitor says:


    Maybe no one else noticed, but in the article you linked to in post #39, it states that Doran and Zimmerman contacted “more than 10,200 experts around the world” yet only 3,146 of them responded to the survey.

    This means that the results they gathered reflect the opinions of less than one third of the world’s “experts” that happen to be listed in the 2007 edition of the American Geological Institute’s Directory of Geoscience Departments. Of this number, 90% agreed that mean global temperatures have risen compared to pre-1800 levels, but only 82% agreed that human activity has been a significant factor in that change. (2,580 is 82% of 3146)

    THEN the report says:
    “In analyzing responses by sub-groups, Doran found that climatologists who are active in research showed the strongest consensus on the causes of global warming, with 97 percent agreeing humans play a role.”

    How many “climatologists” that are “active in research” were there in that subgroup? 10? 30? 300?

    So when you state that “97% of people working on climate research believe it is human caused”-you lead people to believe that number represents 97% of ALL scientists working on climate research in the WORLD-rather than 97% of an unknown number of climatologists in a subgroup taken from 2,580 scientists listed in one two year old directory.

    No offense, but I hope your models are more accurate than your statistical analysis.

  74. SteveP, sorry, but I must agree with #73 — your 97 percent number is extremely misleading and, according to many sources I have read, inaccurate.

  75. Mark Brown says:

    avisitor/Geoff B.,

    I think you are both mistaken. A poll doesn’t need to have a 100% response rate to be accurate. If people who build and conduct polls know what they are doing, they can get very accurate results with a far, far, smaller sample. Think back to the last election — Many pollsters surveyed only a few thousand people, yet their extrapolations from their tiny sample to the entire electorate proved to be accurate, right down to the decimal point. So an accusation of faulty statistical analysis here is entirely out of order, and reflects poorly on both of you.

    As for the charge of being misleading, let’s take a look at what the article says.

    97% of scientists conducting research in climate change thinkc climate change is happening and that it is largely anthropogenic.

    Among ALL those surveyed, 90% believe climate change is real and 82% believe it is anthropogenic. The biggest dissenters were geologists working in the petroleum industry with only 47% and meterologists at 64%. Those conducting the poll said:

    …the take-home message is, the more you know about the field of climate science, the more you’re likely to believe in global warming and humankind’s contribution to it.”

    Doran and Kendall Zimmerman conclude that “the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes.” The challenge now, they write, is how to effectively communicate this to policy makers and to a public that continues to mistakenly perceive debate among scientists.

    I think SteveP’s short paragraph in #39 accurately captures the gist of the article. I do not find it misleading, at all.

  76. Thanks Mark!

    avisitor and Geoff, So if you don’t believe in the ability of random sampling, that’s yours to dispute. That sort of sample survey rate is actually very good, almost a third marvelous, when I took survey statistics in grad school a response rate of 10% was considered great. When a poll says 97% that’s a statistical unbiased estimate of the real rate not just a report of the reported rate of among those that responded. The purpose of a poll is to <em<statically estimate the population, not just report it.

    As far as I know this is most rigorous, statistically valid pool available. Do you have another? (Not the senator from Oklahoma’s list of deniers).

    The funny thing you must believe three things:

    Scientists don’t know what they are doing (listing things people think they’ve they’ve forgotten ).

    That our most advanced modeling tools are easy to dismiss?

    And all scientists are in cahoots.

    ed, I meant they are as good of a ‘simulation’ model as we have for anything. Sorry. Analytic models of things like planetary motion are much better. But Analytic models are very simple and don’t capture much of real world complexity. Philosopher of Science Peter Humphries has said, “The age of analytic models is over.” Meaning simulation models are necessary to capture the complexity we see in the world. His book Extending Ourselves about simulation is very readable and goes into great detail about the challenges we face in modeling a world of complexity.

    Mark D. It’s hard to know if the money will be worth it. But it’s not the warming itself that is scary, it’s the political and ecological instabilities that are introduced. Our economy depends of ecosystem services and if they fail we are in trouble. The view that we are free from the underlying ecologies in this world is just not true. Our fisheries, our rangelands, forestry all are vulnerable, Coral reefs are dying world wide. If you think that global temperature increases just mean turning up the air conditioner, no its not worth it. If your talking about turning Europe into an ice age (a possibility if the polar cap melts and the hyaline pump that drives the gulf stream fails (and the first slowdown has been seen)). And we just don’t know what the effects will be. But they don’t look good and if you don’t think economies are subject to changes in the natural world I would look a little closer at the link between economy, nature and peoples lives.

  77. Mark Brown,

    If we were to take a snap shot of the polls two years preceding the national election we would get a picture that is incredibly far from how things ultimately played out. In those days the race was effectively between Hillary and Giuliani. And so, to say that the polls get accurate results (while they may be true at any given moment in time within very specific parameters) doesn’t address the problem with important “unknowns” that were not being polled–information that was key to determining the final outcome. In short, the polls had almost zero predictive power–in the long run, that is. Only as election day neared did they gain greater predictive power. This is what a lot of CC skeptics are doing cartwheels over when it comes to modeling.

  78. “…not the senator from Oklahoma’s list of deniers.”

    So credentials are meaningless in science nowadays? I’d say hurray! if we were talking about the arts…

  79. Mark Brown, The problem with a ~30% response rate is selection bias in the responders. Presentation, neutrality, wording, survey fatigue, and so on that may affect the response rate among those most likely to provide accurate information. The other problem is that the number of experts qualified sufficiently to to be considered authoritative in this field is probably more like 100, not 10000.

  80. Mark Brown says:

    Jack, your point is correct, but I don’t see how it applies in this context. This is a question about the validity of sampling surveys, not about how statistical models get updated as new information becomes available. Your point about the inability of polls to predict a winner two years out would still hold true even if the poll surveyed 100% of voters.

    avisitor appears to me to be accusing SteveP of playing fast and loose with the data, of using poor statistical methods, and of being misleading. I reject all those charges.

    Statistical sampling is a valid research method. A resonse rate of 1/3 is terrific and allows us to be very, very confident in the results. To say that we need to get a 100% response before we accept the results of a survey is to be ignorant of how anything gets done.

    As for credentials, what can I say? There are folks with PhDs who deny the Holocaust, and a professor at BYU thinks GWB blew up the WTC. I think a consensus of 97% among the people who know the most about the subject is remarkable.

    As long as we are talking about bias though, the most obvious targets are the geologists on the payroll of mineral extraction industries. They are the outliers.

  81. Mark Brown says:

    Mark D.,

    You make fair points. In response, I can only say that we are dealing with a short magazine article summary of a research project. If your point is that it would be nice to have more details of the sample, questions, and results, I agree with you.

  82. ed–

    my response of ‘no’ was to your assertion that most of the additional warming we’ve seen being due to water vapor and clouds. The majority of the total greenhouse effect is created by atmospheric water vapor, but the warming we’ve seen since the industrial revolution can pretty much entirely be attributed to anthropogenic greenhouse gases. It’s true that as the atmosphere warms more water evaporates, increasing the concentration of water vapor, but the increases are small and decrease–fortunate, since otherwise we’d see a runaway greenhouse effect. The guys at Real Climate have a more technical response with some decent links to other responses, if you’re interested.

    I think simulation can be very useful for learning and building intuition and getting ideas about how effects can interact, what factors can be important, what parts are robust or not, and so forth. As you wrote, it’s like an “experimental system.” But as a method of making forecasts in a complex system I’m more skeptical.

    You’re right about what simulation is useful for–figuring out what factors can be important and what parts are robust. Modelers do sensitivity testing, where they basically plug in a range of values and see what impact extreme values will have on the model. The sensitivity of the models to changes in cloud cover, for example, show that the purported high impact of cloud cover is only true if the models are unrealistically simple.

  83. Mark Brown,

    My point is: I wish I could have more faith in the predictive power of climate models–accurate data notwithstanding. But at this point, it seems that there are just too many unknowns for me to feel good about the kinds of drastic measures that some are contemplating in order to insure security in the future.

    Re: Credentials–Of course you are right that a PhD need not insure that one isn’t loony. On the other hand, I don’t care for the implication that all the (many I dare say) credentialed folk who disagree with the consensus must be disingenuous or off-kilter in some way. That smacks of radical orthodoxy to me.

  84. Again Jack, if you question the models, find them doubtable, and in need of repair. Join with others and produce alternative models, test them, use the data they use, make predictions with them that bear out, people sniping from the sidelines, need to get in the game. Join the conversation at the level the conversation is taking place (in the world of complex simulation modeling). Believe me there is no conspiracy among scientists and if we can find our competitors wrong, we will. The deniers are welcome to join the fray. So far their lists of scientists from other fields have not been impressive (sort of like me voting on string theory, I don’t know anything about it but I like the idea, put me on the list).

    And Mark D., if you are skeptical of modern statistical methods to that level, stop taking medicines now, they were tested using the same principles and if you don’t believe them . . .

    Mark B. you say it better than I do! Thanks!

  85. SteveP,

    Nope. No need to get involved. The only real need is to see enough positive results with regard to the *predictive* quality of the models. At that point I’ll be less doubtful. But until then I’m not likely jump on board whole-heartedly–even if there’s nothing better out there to rely on at this point.

    Remember, I’m not dissing the effort and good will that’s gone into modeling up to this point–and I’m not even suggesting that good things aren’t happening. What I don’t like is that those who have the slightest whim of doubt seem to be lumped in with Holocaust deniers.

  86. Mark Brown says:

    Ah geez, Jack. I withdraw the crack about denying the Holocaust, and apologize if you felt singled out.

  87. John Mansfied says:

    As a fluid dynamicist, I’m a little puzzled why biologist SteveP is holding forth on the state of planetary climate modeling.

  88. Steve P., You keep on lumping the reliability of all studies done according to “modern statistical methods” without regard to the nature of the study, the method of testing, the field of inquiry, the quality of the evidence, and so on.

    Pharmaceutical studies in particular are conducted using double blind tests where one population takes the medicine and the other takes a placebo. That is a real experiment. Climate simulations have no means of controlling real world inputs and and that sense are not “experiments” at all.

    A couple other things worth mentioning. Global temperatures a thousand years ago, at the “Medieval Climactic Optimum” were a full degree centigrade higher than they are today. Greenland was colonized during that period. Returning to that temperature is hardly going to be a catastrophe.

    More recently, temperatures in the mid 1930s were every bit as hot as they are today. If CO2 emissions are the primary driver of global warming, the net CO2 emissions for the past 75 years have yet to overcome whatever cooling factors are present. In particular global temperatures fell from 1940 to 1980, leading some to fear a new ice age (if only a “little” one, such as the “Little Ice Age” of three hundred years ago). Solar irradiance was about 1372 W/m^2 in 1940, it dropped to 1370 W/m^2 in 1980 and has risen again to 1940 levels recently. Air temperatures have followed accordingly (and indeed in much greater detail). Did CO2 output fall for forty years? Hardly.

    The carbon tax movement is largely an exercise in environmental paranoia based on an essentially untestable theory. As a theory, it has some merit. As a justification for reorganizing society at extremely high cost, it is laughable.

  89. peckhive says:

    “nature of the study, the method of testing, the field of inquiry, the quality of the evidence, and so ”

    Exactly my point. I’ve never seen the deniers deal with any of these aspects of the models. Ever.

    “Global temperatures a thousand years ago, at the “Medieval Climactic Optimum” were a full degree centigrade higher than they are today”

    Current research (three independent papers) suggests that it was .2 C degrees warmer in Northern Europe and was a regional phenomenon not global as reported by the deniers. This is still controversial, however, because reconstructing tropical temps is hard (best estimates come from ice core data).

    There were some hot days in the 30s in some places, global temperatures? Not even close. Look at the first graph in this post.

  90. Mark Brown says:

    John M., if you follow the link on the sidebar to SteveP’s science blog, you can read a recent post about tsetse flies. Climate change has allowed this fly to extend its range with some devastating consequences.

    Mark D., I’d lie to propose a truce on the sampling issue, since it seem to be a red herring in this conversation. If I may, I’d like to restate the issue like this:

    Approximately 10,000 scientists were invited to respond to 9 questions on the topic of climate change and its causes. Approximately 30% of them responded, and 90% of the respondents are convinced that a)climate change is happening, and b)humans are a major cause.

    The main point still holds, i.e. that the overwhelming majority of scientists have failed to convince the general public, but that the more a person knows about this subject, the more likely that person is to believe it is a serious problem.

  91. John Mansfied says:

    Mark Brown, that’s hardly a qualification to evaluate planetary climate models, and don’t expect SteveP would claim it is.

  92. “I’ve never seen the deniers deal with any of these aspects of the models. Ever. ”

    Ever? That’s what most informed “deniers” are all about. That’s what they’re dealing with continually. The whole heat island question; satellite data–ground versus atmospheric temperature readings; the hugely important question of feedback–just to name a few. Or am I not understanding what you mean by “dealing” with these questions?

    Mark Brown,

    No problem. Just remember–I ain’t afraid o’ no wise cracken’ … green peace … commie … dude.


    Take that.

  93. avisitor says:

    Mark Brown-
    I wasn’t accusing SteveP of playing fast and loose with the data-I’m saying that if he wants to be ACCURATE with regards to this particular poll, he cannot say “97% of people working on climate research believe it is human caused”. He can ONLY say that “97% of the respondents, who are climatologists AND actively working on climate research believe it is human caused”.

    But, again, he can say and believe whatever he wants to. But that “accuracy” word caused me to happen upon something extremely interesting at the link below. I’d love for SteveP and you to have a look. I’d love it even more if Richard Gill would have a look and humor me on a model run…

    I’m a fan of Beck’s work and highly recommend the reading of “180 years of Atmospheric CO2 Gas Analysis by Chemical Methods” published in 2007. In trying to locate another copy of it, I ran across this short, easy to read, and extremely damning-for-GW-proponents paper written by Dr. Timothy Ball in November of 2008. Not only does he reference Beck’s latest work, but he shows information presented in a hearing to the US Senate Committee on Commerce, Science and Transportation in 2004. (amazing stuff).

    His conclusion is stunning. Basically he simply and effectively demonstrates that computer climate models are WRONG because “The entire output of computer climate models begins with the assumption that pre-industrial levels [of CO2) were measurably lower” when in fact they were not significantly lower at all.

    Real, factual, evidence demonstrates that the results published by G.S. Callendar, C.D. Kneeling, and S. Arrhenius may very well have been purposefully biased in order to prove their hypothesis that CO2 levels are rising due to the burning of fossil fuels. In reality, evidence shows that pre-industrial CO2 levels are close to “50ppm HIGHER than the levels put into the computer models that produce all future climate predictions”. (not 270-280 as assumed by computer models-but 330-making our current 385 ppm a much MUCH lower increase and the “human impact” incredibly small)

    His paper references ice core samples, and vegetation stomata, and both indicate that increasing CO2 levels does NOT cause increasing temperatures. In fact, the ice core record shows the exact OPPOSITE.

    I’d love to have Richard Gill run the models based on the REAL pre-industrial average and see what his predictions for the future of our climate would be. Think you can swing that?

  94. Mark Brown says:


    How embarrassing for you. I am unable to do anything with the models, but I am capable of typing names into a search engine.

    Ball is a fraud and a tool of the oil industry. See here:

    Ernst Beck’s work, if that word can even be applied to whatever it is that he does, gets debunked here:

    Do you really consider quasi-scientific publications sponsored by Lyndon LaRouche to be authoritative? Again, I’m embarrassed for you.

  95. avisitor, if all you’re gonna do is link to obvious astroturfing organizations like the mysterious Friends of Science, your contributions here will be of limited value. I don’t have a dog in this fight, really, except to maintain law and order, so as I’ve recommended elsewhere, back off the rhetoric.

  96. peckhive, First of all, most surface temperature data is questionable as a measure of global surface temperatures because the number of stations in urban heat islands. No effort has been made to account for that. For example, the temperature rise in the most populated California counties has risen a full three deg C over the past century, where in the least populated counties it rose about 0.2 deg C.

    An analytical error was recently discovered in the GISS surface data for the U.S. That data now shows 1934 as the warmest year in the twentieth century and the 1930s as the warmest decade (in the U.S.). Unfortunately, satellite based temperature measurements do not go back that far.

    Ice core data from Greenland shows temperatures about a degree C warmer during the Medieval Warm Period and a period known as the Holocene Climactic Optimum from about 6000 BC to 2000 BC where temperatures were ~2.5 deg C warmer than now. See Dahl-Jensen, “Past Temperatures Directly from the Greenland Ice Sheet”, Science, 9 Oct 1998.

    One more thing – the models all predict that temperature increase due to CO2 levels should cause higher mid tropospheric temperatures in the tropics. Extensive radiosonde (weather balloon) temperature data shows there is no such effect. The signature of AGW is non-existent.

  97. Mark D. You provide internet gristmill stuff, that has been dealt with again and again by the scientist working in the field. They know all this and have dealt with it. The deniers just don’t update their sites if it doesn’t fit their agenda.

    Thanks for quoting Dahl-Jensen (and her paper is specific to one place on Greenland Ice sheets and it was a 1 C rise in the medieval warm period (I just read the paper) and again is local). But the important thing is she is a major researcher who argues that CC is real, human caused, and action is needed. Her Swedish institute as done much to show this with the ice core data. Funny that. She must not understand her own data. I see this all the time on the denier web sites, data taken out of context, interpreted in ways the researchers never intended, and never interpreted fully in light of the complete story. Why is that?

    Looking at a single piece of information is often misleading.

    And I don’t think there is any data that the deniers will ever accept that will change their minds. For science new information updates their take on things. Not the denier crowd.

    However, that said, I think it is important that such discussions continue. I’m glad those of you who don’t believe it are thinking about these things. Some advice: Forget secondary sources, don’t go the denier sites for your info. Read the straight reports. Both Science and Nature have done excellent reviews of the science that are highly readable. If you follow the debate among scientists (and there are lots of debates between scientists about CC) you’ll get a feel for what is strong and what not. They are disagreeing but not about what the deniers. They want to get the story right. They are challenging each other all the time. As I said. It is a dog fight.

    “can ONLY say that “97% of the respondents”

    No. if I have a jar of red and blue marbles and I shake it up take a random sample, I have more information than on just the sample I drew. If I find 90% are blue, that is a statement not only about the sample I drew, but it is an estimate of what the proportion of blue marbles are in the jar. That’s why we take a sample so we don’t have to count all the marbles in the jar to get the proportion.

  98. Steve P., Of course you can claim that they have “dealt with it”. Its like cheerleading. It is what we tell ourselves to make us feel good about our position. We don’t have to pay attention to what the other side says. Everything they say is irrational, shoddy and can be dismissed without a wave of a hand. You don’t even have to know why. Just trust us. We know better.

    I get the impression that most of this fabled 97% figure you talk of actually know very little about the subject, have never actually read a real paper summarizing the other side, haven’t read any of the actual literature, they are just operating completely on trust. Most of the big names in the field that I don’t specialize in say this. They *must* be right.

  99. Mark D.: your strident refusal to acknowledge that your position is opposite that of the vast, overwhelming majority of scientists, is frankly breathtaking. “Fabled”? “Cheerleaders”? This seems awfully close to putting your fingers and going la la la la.

    Steve P. is surely weary of knocking down the same pseudoscience over and over and over again. The deniers in this case really don’t have science on their side, so they try to win the battle with the equivalent of a filibuster: just keep on talking until they outjaw the scientists.

  100. One more thing, “denier” is a pejorative term that implies that people don’t believe in any form of global warming. Would you prefer that I call all the people who believe that we should reorganize society based on a theory with no actual evidence (AGW) the “paranoiacs” all the time?

    It doesn’t matter what Dahl-Jensen personally believes, I quoted the results of her research correctly. So tell me, which model, even when backtested correctly matches the medieval warm period and the holocene climactic optimum from first principles?

    The thing is you are not willing to engage any of the actual evidence. That makes it look like you are either too lazy or you don’t know anything about the subject. What is the pro AGW line for the downward trend in temperatures from 1940 to 1980? What is the pro AGW line to ignore the very high correlation of solar activity with temperature movement? What is the pro AGW defense for the IPCC ignoring secondary solar factors (affects on cloud formation)? And so on.

    You want to persuade people, but you won’t do any actual persuading. I could visit any number of pro AGW shill websites to have all these issues ignored. If you can provide me with specific references to places where they aren’t outright dismissed the way you are doing, I would be glad to go check them out. So far you haven’t given me or anyone else here with similar opinions one iota of evidence to suggest that these concerns are unfounded.

  101. Jeremy, you call that “knocking down”? I call it dogmatism.

  102. Mark Brown says:

    Did you really just call SteveP lazy and ignorant?

    Your petulant insistence that people like Gill and Dahl-Jensen are either liars or deluded reflects very poorly on you, and says more about your own limitations than it does about climate change.

  103. Yeah, I’m done.

  104. Steve Evans says:

    Let’s close up this shop.