He’s at it again, again

Predictably enough, the Grauniad has picked up on Hansens target 350 stuff. And what he said before about W Ant now seems to have got transmogrified into:

Hansen said that he now regards as “implausible” the view of many climate scientists that the shrinking of the ice sheets would take thousands of years. “If we follow business as usual I can’t see how west Antarctica could survive a century. We are talking about a sea-level rise of at least a couple of metres this century.”


  1. #1 Nick Barnes

    Is it just me, or have Hansen’s views very quickly shifted from fairly middle-of-the-road climate science to somewhere on the warmest fringe?
    I don’t completely disagree with him, although I’d love to understand more about the basic mechanical processes of GIS and WAIS melting that rapidly, and I often wonder what a world in the grip of that sort of warming would be like (e.g. how much of the southern ocean and the north atlantic would be covered by bergs from the disintegrated ice sheets). But it’s OK for me to be on the fringe; I’m an amateur.
    Off-topic, I have a question about a possible feedback from an ice-free summer arctic. When such an ocean freezes each winter, it pumps huge amounts of heat into the atmosphere (and into space). Far more than an ice-covered sea. Quite a bit of that heat will be lost to space, acting as a brake on warming, a negative feedback. What’s the likely magnitude of this effect? How does it compare to the positive feedbacks of open summer water (albedo, and the rainfall feedback)?

  2. #2 Miguelito


    “The good news, he said, is that reserves of fossil fuels have been exaggerated, so an alternative source of energy will have to be rapidly put in place in any case.”

    I just finished giving my lecture on Peak Oil and I can say that he’s probably wrong about that.

    There is no end in the world’s supply of coal.

    Oil isn’t peaking within the next ten years. Maybe fifteen years for conventional petroleum. Then, with things like the oil sands and other dirty sources, we can probably plateau that value for a few decades longer.

    There’s plenty of oil left in the world to propel AGW.

  3. #3 David B. Benson

    Miguelito wrote “There is no end in the world’s supply of coal.”

    Others have written recently about the impending Peak Coal, say 2025 CE. I believe it was Rutledge at CalTech.

  4. #4 Brian D


    Although it’s off-topic, I’m interested in the reasoning behind your “oil isn’t peaking within the next ten years” line, considering how other sources have said it peaked in 2005.

  5. #5 Phil


    Light crude oil production peaked in 2005, if I recall correctly. That’s not the only oil “produced”.

    My concern, however, is that the deniers and delayers will use Peak Oil as yet another excuse not to do anything.

  6. #6 JCH

    Since he is predicting a 2 to 3 meters this century, then this not the century within which he is saying west Antarctica will melt.

    So within which century is it that he is saying the predominance of west Antarctic ice sheet will melt? The next one? The one after that one?

  7. #7 Miguelito

    I don’t have the time to really get into this.

    It’s hard to understand what a “peak” is in such a regulated market (ie. OPEC’s controls on production).

    In the early new century, oil couldn’t get higher than 82 million barrels per day. It did.

    Then, in the mid-new century, it couldn’t get higher than 85 million barrels per day. It did.

    Now, it can’t get higher than 87 million barrels per day. Given the track record of the naysayers, it will.

    Now, I’m not saying that it’s going to rise as fast as demand is predicting. It’s not going to rise forever. Conventional oil should peak around 2020 based on ultimate recoverable reserves of 3.5 trillion barrels (based on the USGS geological evaluation of worldwide reserve growth). Then, it should be a long plateau thanks to unconventional reserves like oil sands and oil shales.

    As for peak coal, there is no shortage. Supply is so high that mines need government subsidies just to survive because of the low commodity prices.

    Of course, I’m not saying we should be burning it. It’s only going to make AGW worse. I’m just saying that there’s more than enough to do us in if we choose to do it.

  8. #8 Gareth


    The Arctic heat budget is a very interesting topic – and its impact on northern hemisphere even more so. I’ve just posted some further thoughts on the subject. I’m not sure how you get to it being a net negative feedback – given that to get the ice to melt in the first place there has to be a substantial positive term in the budget.

    Re West Antarctica: If Hansen’s right about metre plus SLR this century, then surely the WAIS will just float away. Penguins delivered FOC to Patagonia, South Africa and New Zealand.

  9. #9 John Mashey


    1) The USGS 9and CERA) numbers have traditionally been high.

    2) Look at the EROI of oli sands and shale. Regardless what the price of a barrel of oil is, if it takes that much energy to get it, it’s going to start staying in the ground in any case where economics matters. In addition, some of this requires massive amounts of water, and is located in places that have very little.

    3) See Charlie Hall’s “EROI matters” in The Oil Drum, specifically look at the Balloon Chart.


  10. #10 Nick Barnes

    Gareth: I’m not saying it’s net negative, just that I haven’t seen anything about the negative side of it.

  11. #11 Nick Barnes

    re WAIS just floating away. Nobody knows how ice sheets melt, but it’s not like that. It’s deep submarine grounded, but far too heavy to float easily (that is, it has more ice above sea level than below it). The ice streams are going to go nuts.

  12. #12 David B. Benson

    Miguelito wrote “As for peak coal, there is no shortage. Supply is so high that mines need government subsidies just to survive because of the low commodity prices.” I beg to differ. You can obtain the spot prices for coal at the EIA web site. The prices are going way, way up. The most impressive was an astounding $(US) 130 per tonne for South African metalurgical grade coal. The recent contract price for Australian coal to be delivered next year in China is about $20 per tonne higher than last year (for utility grade coal).

    You may care to look into Rutledge’s writings. I believe his point is that with demand increasing and (most important) governments around the world sseriously overestimating their minable reserves, Peak Coal will arrive around 2025 CE. [It seems that not everybody agrees, but the point about overestimating reserves appears to be of considerable interest.]

  13. #13 cce


    If that paper is correct, sea levels rose an averge of 1.6 m per century at a time when temperatures were 2+ degrees warmer than today, and I doubt the rate of warming then compares to “Business as Usual” over the next 100+ years.

  14. #14 outeast

    I’ve just been reading Gavin’s latest post over at RC, and in the comments thread someone (Alastair McDonald, to be precise) has raised the question of what effect Arctic sea ice melt would have on the albedo. I remember you modelled the impact of a complete loss of arctic sea ice and found little impact – did that take albedo feedbacks into account?

    [Well, it would lower the albedo, though perhaps not by as much as you might expect due to clouds and sun angle.

    Our study found little *long term* impact, because the ice largely regrew each winter. That included albedo effects -W]

  15. #15 outeast

    Thanks William!

  16. #16 Miguelito

    John Mashey:

    I’m not using the CERI estimate. I’m using the USGS for total recoverable reserves. CERI takes a lot of numbers that governments provide at face value (I’m inclined not to believe governments like Iran and Saudi Arabia). Their annual production rate projection is ridiculous over the next forty years. I’m inclined to say impossible.

    But at least the USGS looks at the geological numbers behind things, numbers that are used to calculate reserves. In that way, I’ve got confidence that they’ve done it right. The modeling they use is a widely applied technique throughout industry. To me, as a geologist, it makes sense. And it’s good methodology.

    Furthermore, for more pessimistic projections from peak-oil theorists, Hubbert’s linearization provided the wrong ultimately recoverable reserves in the US. His original estimate of 150 billion barrels ultimately recoverable and his more “optimistic” value of 200 billion barrels both fell short of the now probable 230 billion barrels. Peak oilers say that we’re not making new finds, new discoveries. It’s true. But they neglect that the bulk of reserve growth comes from existing fields as rates of recovery increase and new smaller pools within those fields are found (something that the usgs has looked at).


    Again, I’m not saying that we’re going to produce forever. I’m saying that projections of us peaking today or tomorrow are just plain wrong. Reserve growth will probably push us over 3 trillion barrels worldwide. This will create a peak in about 2020 and a longer plateau if you include things like the oil sands in that as we deplete conventional reserves.

  17. #17 Hank Roberts

    > little *long term* impact, because the
    > ice largely regrew each winter.

    Ok, but the albedo of winter ice only matters outside the Arctic Circle during the dark time.

    At the almost flat angle of incidence with the sunlight from right at the horizon, is the albedo of open water still much less than that of ice?

    [I don’t think albedo is very angle-dependent, at least not in climate models. In reailty, it might be different, and waer might be a special case (see Eric Swanson on sci.env) -W]

  18. #18 AdrianJC

    Reserve growth can happen due to real improved recovery fraction or better reserve estimation technique. The early-PO argument is that much of past reserve growth was due more to the latter, and so one cannot expect future reserve growth to be anywhere near as large since reserve estimation is not being improved much more than it is now.

    If you want to include heavy oils (tar sands and oil shales) in your reserve estimate, please note that these reserves are very difficult to produce. To achieve high flow rates one needs a lot of energy input in the form of heat, which currently comes from natural gas which happens to be peaking in North America. Liquified NG is not going to be cheap. As for all the light sweet crude that takes very little energy to produce, pump and refine? It peaked a couple years ago.

    It’s like winning a billion dollar lottery to be paid at a rate of just ten dollars a week — are you really a billionaire? To quote Steve Andrews, “It’s the size of the tap, not the size of the tank” that really matters.

  19. #19 David B. Benson
  20. #20 Benjamin Franz

    To put some numbers on this.

    2005 annual energy consumption by type (measured in units of 1015 BTUs):

    Petroleum: 169
    Dry Natural Gas: 107
    Coal: 122
    Hydro: 29
    Nuclear: 27
    Other renewables: 4

    There is something like 150 years of coal at the current level of use.

    If you try to replace natural gas and oil with coal (using a 1 to 1 substitution on the BTU level), that drops to about 70 years. I’m obviously over-simplifying, but the point remains: “150 years” isn’t the applicable number. It isn’t even close. And no one really wants to see what the climate would look like if we burned all that coal this century.

    One way or another, the era of cheap fossil fuels will be over in less than a century. Very probably in less than half that time. Our only real long term hopes are nuclear fusion and/or truely massive solar projects.

    Oh, and the “C” word: Conservation. We need to be using much less energy per capita very shortly.

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