Global Warming

A few months ago a friend of mine engaged me in a discussion about the controversy surrounding global warming.  If you are surprised to hear that there is still controversy, read on; I was equally surprised.

The controversy is not so much whether the atmosphere is heating up, but rather the cause and projected magnitude.  As anyone familiar with modeling complex systems understands, the time horizon for accurate predictions is inherently short due to chaotic and otherwise complex feedback dynamics.  So it shouldn’t really be a surprise to learn that climate predictions even with the most detailed and best crafted models have a hard time with accuracy in predicting more than a year out.  As a consequence, it should also not be a surprise to learn that the role CO2 plays in changing global temperature — and the extent to which it does — is highly uncertain.  There are good reasons why we should seek to reduce carbon emissions, but whether global warming is one of them is unclear.  What struck home for me was learning that the uncertainty for a 50 year projection was plus or minus 55 degrees centigrade.  This does not necessarily mean that it is possible for the atmosphere heat up or cool down by that much, but rather the models used in making temperature predictions are useless for long-range projections.  And it matters not whether all the different models converge to the same prediction if the uncertainty factor (as measured by propagated error) is large for all of them.  For a good overview of these arguments and the data, see Patrick Frank’s article.

Just because the prediction game is difficult and uncertain doesn’t mean we shouldn’t take action to protect against disaster scenarios.  Even if we feel 99% certain that a catastrophe will not occur, we should be looking really hard at how to prevent or mitigate it in the 1%.  The more dire the consequences, the harder we should try.  The data is clear that global warming has been happening, nobody really refutes that anymore.  Logic dictates that without further evidence to the contrary, we should assume that the atmosphere will continue to warm, at least for some period of time.  The aggregate effects of global warming are also hard to predict, but at the very least we can be pretty sure that many people will die, through famine, lack of clean drinking water, disease, drowning, and a number of other factors.  There are several schools of thought on how to react to this sobering situation.  One is to try to reverse global warming and stabilize the temperature.  Another is to mitigate the toll on life and suffering (both human and non-human).  A third approach is to attempt both in some combination.  Ultimately the debate over global warming is over which of these routes we should take.  And the route that you advocate should depend on your belief in the certainty of the various predictions.

If you believe with high certainty that CO2 is the main culprit (this is called the “anthropogenic global warming” hypothesis or AGW for short) then it makes a lot of sense to put all your eggs into basket number one, assuming that you can have an impact in time.  If you are highly certain that CO2 is not to blame, you might prefer to take the second approach, using the massive resources that would otherwise have been spent curbing emissions to instead address the more direct causes of death and suffering that will be greatly exacerbated by global warming.  But given Frank’s arguments (and that of many other highly respected climatologists), it would be foolish to feel certain enough of either claim to put all your eggs into one basket.  The only rational approach is to do both in some combination.

But how do we know how to spend our limited resources appropriately, especially when new data unfolds constantly which should feed into our approach and spending decisions?  My skeptical friend wrote me the following email the other day, which put a smile on my face:

You know where I stand on the science here, but there are obviously strong feelings on both sides and I’m not more than 90% confident we won’t experience a catastrophic AGW outcome.

Ross McKitrick has come up with an absolutely brilliant scheme that allows each side to put its money where its mouth is.  It turns out that the climate models predict a very specific AGW heat signature–with warming occurring first and foremost in the tropical troposphere.  So he proposes to tie a carbon tax to temperature rises there.  If AGW is true, then this tax will steadily increase.  If it’s false, it will remain near zero (ignoring subsidies under global cooling) regardless of warming from other sources.  Then we can all just shut up and let nature and the economy take their courses.

This is a plan I would strongly back.  Hooray for clever people!

This blog has a good overview.  This is Ross’ source material.

Presumably, tax revenues from this scheme could be put directly towards mitigating death and suffering, and voila, we have a self-tuning adaptive solution.  The astute reader will realize though that in the event that carbon emissions are not a significant factor in global warming (but warming persists nonetheless) there is no way to pay for tragedy prevention/relief.  While this is true under McKitrick’s model, there’s nothing that says we can’t as a society decide to throw carbon emissions under the gas guzzling bus (so to speak) and let the tax float with global average temperature.

Your thoughts welcome.

  • James
  • mick

    You have to multiply that .01 by the negative payoff of the disaster and add it to the .99X cost to see if it’s worth it.

    The costs of the disaster scenario are not going to be infinite.

  • mikemac1

    John A. Warden III, a U.S. strategy expert recently posted this about Global Climate Change: Thinking Strategically About Global Climate Change. It would be interesting to hear how your readers view his positions and the need to establish the future state of the global climate before embarking on a lots of tactical solutions to a percieved problem.

  • Kevin Dick

    mick and mikemac1,

    I’m the skeptical friend in question, so I agree with you both in some Platonic sense. However, what we have right now is not a rational debate, it is an ideological debate–a wasteful, harmful ideological debate that I don’t think skeptics can win in a reasonable amount of time.

    What I like about the T3 tax is that it allows me, as a skeptic, to bet against the catastrophists. I think I’ll win the bet. They think they’ll win the bet. Terrific. We can just make the bet and move on to to a hopefully more rational debate about something more important.

  • Ben

    I’ve pretty much given up on actually trying to debate global warming with skeptics. It seems that everyone on their internet has their own set of “facts” they cite, which are all wildly incompatible with each other.

    My impression is that, among scientists who study climate for a living, ~95% of them believe global warming is human-related. For me, that’s good enough. Yes, group-think is always possible, but I wouldn’t bet humanity’s future on the possibility that climate scientists are all deluded.

    That said, I would have no objection the proposal above. Under that scheme, we’d be taking effective steps against global warming damage no matter what the cause. Hooray!

  • Kevin Dick

    @Ben. This is a great example of how this idea can build bridges. While I think your impression of scientific consensus is wrong, we don’t have to debate the merits of our respective sets of facts. We can just bet.

    But before you take the bet, you should be clear that, …”no matter the cause.” isn’t exactly right. The tropical troposphere is expected to warm much less if warming is driven by the sun or current oscillations (which may in turn be driven by the sun).

    So the tax is likely to only ameliorate warming damage if humans truly cause it. We’d still need to take steps towards adaptation if there is substantial warming or cooling due to natural factors.

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  • Brian Macker

    “So it shouldn’t really be a surprise to learn that climate predictions even with the most detailed and best crafted models have a hard time with accuracy in predicting more than a year out.”

    Do “climate predictions” (I guess you mean models) even predict a day out? Can you even measure “global temperature” over periods shorter than a year given the fact that we need a complete seasonal cycle to get an average? Nope, doesn’t work. You can’t go back and compare with one year ago at the same season either. There is no such method.

    So how can you imply or even believe that “climate predictions” are accomplishing anything at all? They are no good for any length of time long or short.

    “Even if we feel 99% certain that a catastrophe will not occur, we should be looking really hard at how to prevent or mitigate it in the 1%. The more dire the consequences, the harder we should try.

    How about this. Let’s say we don’t do the impossible and reduce CO2 levels back to preindustrial level and say we merely completely stop current and future CO2 production. How many people would die then, and how certain are we that they would die? I’d say billions and I’d say the certainty approaches 100%.

    On the other end of the spectrum we have the scare that maybe someday someone might be too stupid to evacuate his house during a hurricane warning (a warning made available by burning CO2). Funny thing is that this is not a new problem. This happens now and is due to weather, and not climate.

    In addition CO2 is a plant fertilizer and an important one because it is a limiting factor in plant growth in many areas, and one that agriculture can’t cheaply enhance. Our most fertile crop lands will become more productive. Increased temperatures will also give us longer and warmer growing seasons, plus additional rains.

    “The aggregate effects of global warming are also hard to predict, but at the very least we can be pretty sure that many people will die, through famine, lack of clean drinking water, disease, drowning, and a number of other factors. “
    Drowning? Do you think people are going to be spending more time in their swimming pools due to warm temps?

    One can make all sorts of scary predictions. How about this. If temperatures remain constant there is a danger that disease will adapt to the more constant temperatures and spread more rapidly.

    How is this any different than Pascal’s Wager? Better believe in God because well the dangers are so high and the costs so little. However in this case the costs of not using fossil fuels are enormous, and the dangers are not only speculative, but are dangers that we already cope with. Yep, people in the Neatherlands have coped with lands subsiding into the seas at a much greater rate than predicted rates due to these faulty models. Yep, we have been dealing with hurricanes, tornados, rainfall, floods, etc. long before we even started mining the first fossil fuels.

    More people die in 3rd world countries from the weather than in those countries that use lots of fossil fuels. Perhaps if they used more they wouldn’t have such problems.

    The data is clear that global warming has been happening, nobody really refutes that anymore. “

    Refutes? I guess you meant disputes. Sure there are people who dispute it because it’s such a vague concept. What does “global warming” mean? Does it mean that temperatures have warmed since the last Ice Age? Does in mean that temperatures have warmed since “The little Ice Age”? Does it mean that temperatures have warmed since the ’60s. What precisely does it mean? Does it mean that humans have so influenced the environment that we have affected it by an order of magnitude above natural fluctuations?

    All other things being equal, well more CO2 is going to mean higher temperatures. What’s in dispute is how much. What’s also in dispute is whether it is cost effective to make an attempt to prevent something from changing that has a long history of changing. We certainly don’t want the natural course of events to take place and for the next ice age to start on schedule. Now that would be a disaster that would dwarf any problems due to higher temperatures.

  • Brian Macker

    “So he proposes to tie a carbon tax to temperature rises there. If AGW is true, then this tax will steadily increase. If it’s false, it will remain near zero (ignoring subsidies under global cooling) regardless of warming from other sources. Then we can all just shut up and let nature and the economy take their courses.”

    I can think of no better way to set up a bad incentive for the temperature data to be fudged to the the benefit of government. Isn’t it bad enough that they feed us bad numbers on inflation now? Understating it so they can bilk old folks out of their inflation increases, and not pay higher rates on Treasury Inflation Protected Securities.

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