Hansen’s final Iowa testimony

NASA’s James Hansen has posted here his final testimony submitted to the Iowa Utilities Board on the proposed coal-fired power plant in Iowa.

You can send this to anyone seeking a clear, general-audience primer on

  1. the state of the science on climate change
  2. why we need to take immediate action
  3. what we should do about coal.

17 Responses to Hansen’s final Iowa testimony

  1. Ron says:

    In his testimony, Hansen made an astounding statement. He said that humans’ presence on the Earth makes another ice age impossible, unless we choose to have one.

    I don’t quite know what to say to that. If true, we humans have truly awesome powers to control this planet. ‘Godlike’ might not be too strong a word.

    I’m sorry Joe, but Saint James is suddenly sounding like a nut to me.

    Back in the old days, ‘testify’ meant to swear by your testicles. We’ve come a long way ….

  2. John McCormick says:


    You are a true minimalist when it comes to thinking through the global warming trajectory and where that might take this planet’s climate systems when the trapped CO2 and CH4 find their escape routes from beneath the tundra and permafrost.

    Or, does that whole idea give you indigestion and therefore, necessarily must be dismissed.

  3. Ron says:

    So you buy that extreme extrapolation John? You understand that it’s not really a scientific conclusion, but a leap of faith, right?

    Would you bet your testicles on it?

  4. Joe says:

    It is a scientific conclusion — and I would not bet the health and well-being of the next 50 — or possibly 500 — generations on your side.

    He doesn’t need to bet his testicles, whatever that means. Just a few percent of GDP by 2050.

  5. John McCormick says:


    You are a crass individual and desperately needing an audience. I recommend the Howard Stern show.

    Otherwise, find another place to park. Discussing AGW not your brightest moment but it is your playtoy.

    You will not find me responding to anything you have to say in the future. But, what do you care. Boredom is a worse fate for you.

  6. John McCormick says:

    And, Joe, a bit more scrutiny in allowing language in posts is called for.

    I believe people of all ages and sensibilities visit your blog and all deserve courtesy and respect.

  7. Ron says:


    I didn’t mean to offend your sensibilities. I was commenting on the root meaning of the word ‘testify’. It used to be that a higher standard of truth was involved in testimony. I fear the word is being used rather loosely these days.

  8. Lou Grinzo says:

    I would consider mankind’s ability to alter the planet’s climate no more “godlike” than many of the other things we’ve grown used to over the decades. Vehicles that carry people into space, under the seas, and through the air, the ability to communicate over vast distances, genetic engineering via direct manipulation of DNA (as opposed to cross breeding plants and animals), the elimination or nearly so of many diseases and medical conditions, and, well, most items in the Victoria’s Secret catalog.

    Given how much we’re learning about climate and how delicately balanced it is, I think it’s not at all surprising that human beings could pour CO2 (which hangs around a very long time, resulting in a cumulative effect) into the atmosphere at a rising rate for well over a century and inadvertently bring us to the point we see today. And considering the relatively low level of per capita emissions it would take to hold off a new ice age, I think Hansen’s comment makes perfect sense, even if it does seem a bit startling the first time one hears it.

  9. David B. Benson says:

    David Archer has written an interesting paper about how long it will be until the next stade (major ice sheets) depending upon how much carbon we put into the air. Based on that paper, I’ll say that James Hansen is correct, unless humans outlast the supply of fossil fuels, including the non-traditional ones.

    In any case, putting off a stade for 250,000 years is certainly within our current capability. We may not like (or survive) the side-effects. Maybe the lack of survivability figured into Hansen’s remark.

  10. Ron says:

    Lou and David,

    I’m startled by your credulity.

  11. Lou Grinzo says:

    Ron: I’m startled by your [insert fancy but really insulting word here].

    Make your argument. Show us why you’re right and James Hansen is wrong. So far, all you’ve given us is a visceral reaction to something sounding almost “godlike”, an offer for someone to bet a piece of his anatomy on the issue, and a comment about the credulity of two people in this conversation.

    I’m not a climate scientist, so I can’t say with much authority that one side is right over another. But until an expert I trust, Hansen, is shown to be wrong, I’ll continue to side with him over people I don’t know, even by reputation.

  12. Ronald says:


    Do you truly get what you are doing. Out of that 60 pages in the report, you only thought the part that you would comment on was the 0.01 percent that you could lampoon. What about the important 99.99 percent that describes our and future generations real problem? Is it your view to be against something that you can’t be 100 percent for? Taxes are theft, so any body who talks about them other than they are theft is 100 percent wrong? I can poke holes in any theory about anything, so it’s all automatically wrong?

    Good gosh, I’m going to quote something Ronald Reagan said to somebody that I heard on television today. ‘Just because I agree with somebody 80 percent of the time, doesn’t make him 20 percent my enemy.’

    And that’s how the world is. Just because everything isn’t 100 percent true, that doesn’t make it your enemy.

  13. David B. Benson says:

    I am only an amateur with regard to climate science, after most of a lifetime as an amateur geologist. I’ve read 3.5 climatology books and about 25 peer-reviewed papers. I think I know my way now around some aspect of climatology, although far from expert. I know the limitations to my knowledge and, after a career as a research scientist, know not to go beyond those limits anymore than I can help.

    That said, David Archer’s paper does quite well at estimating the effects of varying amounts of carbon in the active carbon cycle and using the ice core records to estimate parameters. One aspect which is known with great certainty is the orbital forcings far into the past and also into the future. From orbital forcing theory, and assuming no anthropogenic carbon in the active carbon cycle, one can see that there is some chance of a stade (massive ice sheets) in 20,000 years. But adding carbon to the active carbon cycle reduces that small chance to zero.

    The next chance of a stade is 50,000 years from now. That one is quite likely, baring the additional carbon. Eliminating that chance will take rather more carbon added to the active carbon cycle.

    There is so much carbon not in the active carbon cycle, that yes, each attempt at a stade can be eliminated, until there is no civilization to do so any longer.

    It is not credulity, it is being in possession of the facts of the matter. This one wasn’t hard. Try me on a harder climate question.

  14. Ron says:


    Then you’re the guy I want to talk to. You’ve perhaps read enough to explain the proof behind this accepted hypothesis.

    How have the effects of the varying amounts of carbon been established and verified? I know there has been some corroborating evidence seen, and some success with models, but at the same time there is a lot of contrary evidence and the models just don’t seem to reflect reality very well – they can’t be used yet to predict actual climate effects.

    Or so it seems to me. But maybe you can convince me.

    Joe and others just state the hypothesis, like a point of faith. Maybe you can do better.

  15. David B. Benson says:

    Ron — A good palce to go is Real Climate

    at the top there is a link start here. Start there. If you need more, there is also, down the sidebar in the Science section a link to the AIP Dicovry of Global Warming site, which is both readable and thorough.

    Yes, the physics of global warming (so-called greenhouse) gases has been understoof for well over a century. The evidence from ice cores is in agreement and is overwhelming. THere is no contrary evidence. The models reflect reality reasonably well and have made predictions which have subsequently been observed. Hence, with some caution, the models cn be used for some forms of predictions.

    However, there is no need for using the global circulation models to predict the amount of warming due to increased carbon. It is an easy calculation.

  16. Ron says:

    I’ve been to the site, but haven’t had any more luck engaging anyone in a serious discussion of the hypothesis than anywhere else. They seem to be operating under the assumption that the hypothesis is so well established no further discussion of it is necessary.

    Maybe I should dig deeper and see if the information is there nonetheless.

    I disagree though that the models do a good job of prediction. Actual temperatures don’t agree with predictions, nor do the predictions of a doubleplusungood hurricane season with the actual hurricane seasons we are seeing.

    As I have pointed out previously, the Old Farmers Almanac does a much better job of predicting weather and trends and they rely mainly on solar cycles, with some folklore thrown in….

  17. David B. Benson says:

    The hypothesis? THe effect of global warming (so-called greenhouse) gases upon global temperatures is thoroughly understood. Read the AIP site.

    You are wrong about the models. The predictions are quite good. In particular, what is predicted is not more hurricanes, but more intense ones. It will take about 30 years of data to check that. Be patient.

    Climate is not the weather. Climate general circulation models do not predict the weather.

    Go do your reading.