30 Responses to “Reactions to Searching for a Signal”

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1. William Connolley Says:
   March 13th, 2006 at 9:50 am

   You complain that people often misunderstand your position, but in large part thats down to the words you use (if practically everyone, from both sides of the debate, haven’t understood you then its past time to start wondering why). This time you’ve included “Anthropogenic climate change is real” as number 1 so there will be no doubt

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2. Mark Bahner Says:
   March 13th, 2006 at 10:28 am

   “2. Greenhouse gas reductions make good policy sense.”

   Let’s focus on CO2:

   1) When you write, “reductions,” do you mean in emissions, or in atmospheric concentrations, or both?

   2) When you write, “reductions,” do you mean reductions now, or just sometime before the end of the century?

   3) When you say “good policy sense” do you mean for “the world” or “the United States,” or both?

   4) If you mean CO2 emission reductions right now make good policy sense for either the United States or the world, why do you think immediate emission reductions make good policy sense?

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3. John Fleck Says:
   March 13th, 2006 at 10:59 am

   William -

   Another possible explanation of the way “everyone, from both sides of the debate,” misunderstands Roger’s work may have to do with the tribal nature of the discussion. Everyone’s trying to figure out which tribe Roger’s a part of.

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4. coby Says:
   March 13th, 2006 at 11:19 am

   Good point John,

   And it is commendable that Roger has the courage of his convictions to resist being pigeon-holed. But I also suspect William has a point, only I have to be careful because I have not followed Roger’s writing long enough.

   Roger, you said “I do worry that the politicization of climate science is reaching epidemic proportions with profound consequences for the field”. Now we established last thread that politicization is not by definition wrong. And given your definition of politics and the urgency and magnitude of the threat that AGW poses to the planet, both for human and natural concerns, then I suggest that politicization of climate science is essential and you must focus on how it is happening and how it should happen rather than bemoaning that it is happening.

   I look forward to the answers to Mark’s bait…er.. questions as well.

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5. Roger Pielke Jr. Says:
   March 13th, 2006 at 12:17 pm

   Coby- Thanks, agreed. On the negative effects of excess politicization, please have a look at these pieces to start:

   http://sciencepolicy.colorado.edu/admin/publication_files/resource-1621-2004.18.pdf

   http://sciencepolicy.colorado.edu/admin/publication_files/resource-69-2000.18.pdf

   http://sciencepolicy.colorado.edu/admin/publication_files/2003.01.pdf

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6. Roger Pielke Jr. Says:
   March 13th, 2006 at 12:23 pm

   Hi William- I actually am not worried too much about those few people who may misunderstand my message. Its some of the folks who understand it 100% that I’m worried about, as described in this post.

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7. Roger Pielke Jr. Says:
   March 13th, 2006 at 12:40 pm

   Mark- Thanks. I’ve addressed these issues in this paper:

   http://sciencepolicy.colorado.edu/admin/publication_files/resource-1841-2004.10.pdf

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8. Andrew Dessler Says:
   March 13th, 2006 at 1:16 pm

   Mark-

   While I don’t speak for Roger, I’ll take a stab at your questions:
   1) When you write, “reductions,” do you mean in emissions, or in atmospheric concentrations, or both?

   actually reducing atmospheric CO2 is likely too difficult — just stabilizing it would be a tough job. so when people talk about “reductions,” they’re talking about emissions.

   2) When you write, “reductions,” do you mean reductions now, or just sometime before the end of the century?

   in order to keep atmospheric CO2 from exceeding a doubling, we need to start reducing CO2 emissions in the next decade or so.

   I know that you think that CO2 emissions will decrease on their own. if so, GREAT!, that means that any program we implement to reduce CO2 emissions can be scaled back as a natural leveling off becomes obvious.

   3) When you say “good policy sense” do you mean for “the world” or “the United States,” or both?

   good for everyone.

   4) If you mean CO2 emission reductions right now make good policy sense for either the United States or the world, why do you think immediate emission reductions make good policy sense?

   this question doesn’t make sense. please rephrase.

   Regards.

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9. Mark Bahner Says:
   March 13th, 2006 at 3:08 pm

   Hi Roger,

   You wrote, “Mark- Thanks. I’ve addressed these issues in this paper:…”

   Roger- Call me “clueless” (as lesser men than you already have) but I can’t find answers to my questions in the paper you cited.

   Could you direct me to the specific part(s) of the paper that address each question? Or even better, can you answer each of my 4 questions with a short answer, AND direct me to the part of the paper that addresses the question in more detail?

   For example:

   Mark Bahner question: “1) When you write, ‘reductions,’ do you mean in emissions, or in atmospheric concentrations, or both?”

   Roger Pielke Jr. answer: “Both” (or “Emissions,” or whatever)…and…”See page 549, column 2…” (or whatever).

   Mark Bahner question: “2) When you write, ‘reductions,’ do you mean reductions now, or just sometime before the end of the century?”

   Roger Pielke Jr. answer: “Now” (or “before the end of the century” or whatever)…and…”see page 555, column 1″..or whatever.

   Thanks,
   Mark

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10. Roger Pielke Jr. Says:
    March 13th, 2006 at 7:38 pm

    Mark-

    It is ironic to see a discussion on energy polcy break out when I post on natural disasters, kind of makes the point, no?

    I’ll oblige your request:

    1. Both
    2. Now
    3. Both
    4. Huh?

    If you want more nuance, do wade through the paper, especally the last third. Thanks!

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11. Mark Bahner Says:
    March 13th, 2006 at 8:27 pm

    Hi Roger,

    You write, “It is ironic to see a discussion on energy polcy break out when I post on natural disasters,…”

    Actually, I don’t see it as a “discussion on energy policy” if you think it’s a good policy idea to either reduce emissions of CO2 or to reduce CO2 concentrations in the atmosphere (once the CO2 has already been emitted). You clearly seem to have something against CO2 in the atmosphere.

    And since you think it’s worth doing immediately, you apparently have a problem with concentrations at or somewhat above their current levels.

    As for Question #4…I’m trying to figure out WHY you think it’s good policy to reduce CO2 emissions immediately. What objective and scientifically valid study have you read that looks objectively at both the problems and benefits of CO2 in the atmosphere at its current or somewhat higher values?

    Do you think the problems that CO2 is causing (that outweigh the benefits) exist right now, or is it “good policy” because of problems you think may exist in the future?

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12. Tom Rees Says:
    March 14th, 2006 at 8:18 am

    Roger, you point out the fact that should be obvious to anyone with an interest in the subject – that there is no detectable AGW signal in disaster losses. If you find that people have a problem with that perhaps you should just point them in the direction of the IPCC TAR, which says as much

    The more salient question, to my mind, is when should we expect to be able to see a signal above the background noise: Now? In ten years? Never? If someone could point me to an analysis along these lines I’d be much obliged. I suspect that there is no reason to be expecting a detectable signal now or in the next 10 yrs or so, simply because the amount of warming during the period of good observational record has been quite small (<0.5 deg C).

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13. Roger Pielke Jr. Says:
    March 14th, 2006 at 9:15 am

    Tom- Thanks, but the IPCC TAR actually got this one 100% wrong, see:

    http://www.ostina.org/html/bridges/printer_friendly.htm?show=individualArticle&article=1284

    Your question is a good one. The ability to see a signal has a lot to do with the quality of our disaster data, which is noisy, in the context of profound societal changes and relatively small signals of changes in extremes. However, if extremes change dramatically, and if we carefully collect data, I would not rule out DETECTION of a climate signal in the record before too long (how long exactly, not sure). ATTRIBUTION is a different matter, and may take a very long time, though we may be in an extended period of “suggestive” findings.

    I am pretty sure that at no point in the future will the science suggest that it makes sense to use energy policies as a mechanism of modulating extreme events in order to affect disaster losses, given the role of societal vulnerability.

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14. Harold Brooks Says:
    March 14th, 2006 at 9:58 am

    In trying to get ready for the Climate Change and Disaster Losses Workshop (http://sciencepolicy.colorado.edu/sparc/research/projects/extreme_events/munich_workshop/workshop_info.html), I’ve started trying to put together a toy statistical model of US tornado damage. It works in wealth-adjusted damage, as Chuck Doswell and I used in our historical analysis of tornado damage. The model takes as input the number of tornadoes per year, the distribution of tornadoes by intensity, and a distribution of damage amount by intensity class. It’s not especially well-tuned as of yet, but I think the results are illustrative. I have to put in large changes in the parameters to see something past the wealth adjustment, e.g., double the probability that tornadoes will be violent or increase the number of tornadoes by ~30%. At the moment, I’m not even taking into account the interannual variaiblity of tornado numbers.

    The concentration of a large fraction of damage in a small number of events makes it almost unlikely we’ll be able to detect a signal in the wealth-adjusted losses without really large physical changes. Based on wealth changes, I’d expect raw, unadjusted tornado damage to double every decade or faster, but I’m not optimistic about detecting anything past wealth. I admit I’m not completely confident in the model yet, but I’m pretty sure it’s on the right track.

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15. Mark Bahner Says:
    March 14th, 2006 at 10:08 am

    Hi Roger,

    I have four additional questions.

    1) By my calculations, the U.S. is currently about 12% above its 1990 emissions of CO2. And Kyoto required the U.S. to reduce to about 8% below 1990 emissions. Therefore, in order to meet the CO2 reductions the U.S. would have committed to under Kyoto (if the Senate had ratified Kyoto), the U.S. would have to reduce CO2 emissions by 20% from present. This is about 330 million tons as carbon per year (of 1.2 billion tons of carbon dioxide).

    Three studies have produced cost estimates ranging from $221 to $348 per metric ton of carbon reduced. This works out to an annual cost of approximately $70-$100 billion.

    http://www.eia.doe.gov/oiaf/kyoto/cost.html

    Suppose the U.S. government spent that amount of money annually for the next decade. That’s $700 billion to $1 trillion, total. The total amount of emissions reduced would be 3.3 billion metric tons as carbon (i.e. 10 years at 330 million metric tons per year as carbon).

    A reduction in emissions of 3.3 billion tons as carbon would produce a reduction in CO2 concentration in the atmosphere of less than 1 ppm (i.e. in 2015, the concentration would be approximately 399 ppm, instead of approximately 400 ppm).

    Is that good policy?

    2) If the U.S. government funded development of an ocean iron fertilization system, such that the reduction of atmospheric concentration by 1 ppm would cost 1/10th as much as the cost of reducing emissions, would that be even better policy?

    In other words, if the ocean iron fertilization system reduced the atmospheric concentration by 1 ppm, at a cost of $70-$100 billion, would that be an even better policy?

    3) If the U.S. government funded the deployment of a hurricane reduction system, such that every landfalling hurricane was reduced by 2 Saffir-Simpson categories (e.g., Category 4 to Category 2), and the cost of this system was $70-$100 billion, would that be a good policy?

    4) If the federal government had only the money to implement 1 of the 3 policies above, which of the 3 policies would you recommend that the government implement?

    Best wishes,
    Mark

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16. Roger Pielke Jr. Says:
    March 14th, 2006 at 10:21 am

    Harold- Good stuff. Lets have you do a post for us on this when you are ready! Thanks!

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17. marlowe johnson Says:
    March 14th, 2006 at 3:11 pm

    Mark,

    Here are some point by point thoughts on your 1st question/statement.

    1)”By my calculations, the U.S. is currently about 12% above its 1990 emissions of CO2.”

    Actually, “Between 1990 and 2004, CO2 emissions from fossil fuel combustion increased from 4,696.6 Tg CO2 Eq. to 5,656.6 Tg CO2 Eq.–a 20.4 percent total increase over the fourteen-year period.”. Google “u.s. inventory of greenhouse gas emissions” and you’ll get the EPA’s inventory site on the first hit.

    However, as I’m sure you know you have to also consider other GHGs like N2O, SF6, CH4, and sinks when calculating your inventory. When these are taken into account the increase on a CO2-equivalent basis is closer to 16% — largely because N20 and CH4 emissions have declined. Overall, then, the U.S. would have to reduce emissions by 24% to achieve its Kyoto targets not 20%.

    I admit that it’s a small difference, but I’m curious where your “calculation” came from when the information is so readily available (page 4 of the executive summary).

    Now by my calculation 24% of 7,074.5 Tg CO2 Eq is approximately 1,700,000,000 tonnes or almost 6 times higher than your 330 million figure.

    Btw, I find it interesting that you again reference the EIA studies without also mentioning that they explicitly exclude the flexibility mechanisms included in the Kyoto Protocol (which leads to grossly overstated costs IMHO). In fact, it is much more likely that $/ton costs will be closer to theh 30-60 range than what the levels the studies suggest and current experience in the EU market certainly seems to support this.

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18. Mark Bahner Says:
    March 14th, 2006 at 3:58 pm

    Marlowe Johnson writes, “Overall, then, the U.S. would have to reduce emissions by 24% to achieve its Kyoto targets not 20%.”

    OK. Whatever.

    “Now by my calculation 24% of 7,074.5 Tg CO2 Eq is approximately 1,700,000,000 tonnes or almost 6 times higher than your 330 million figure.”

    Your calculation for the required U.S. emission reduction is in CO2 equivalents. My calculation was for U.S. emission reductions in CO2 **as carbon**. (I did it in that form, because that’s how the costs were reported in the document I referenced…as carbon.) To get the equivalent value *as carbon,* you need to multiply your value by 12/44 (the molecular weight of carbon divided by the molecular weight of CO2).

    So your calculated value is approximately 460 million tons **as carbon**. Again, whatever…330 million tons as carbon, or 460 million tons as carbon. Either number will do.

    “Btw, I find it interesting that you again reference the EIA studies without also mentioning that they explicitly exclude the flexibility mechanisms included in the Kyoto Protocol (which leads to grossly overstated costs IMHO).”

    Yes, I didn’t include the “flexibility mechanisms” because they basically allow EU countries to buy credits from Russia, so that NO ONE makes any real reductions. (That’s because Russia’s “credits” simply come from the collapse of their economy between 1990 and the present.)

    BTW…I have since realized that reducing emissions by a total of 3.3 billion tons (**as carbon**) over 10 years would actually reduce the atmospheric concentration of CO2 by a grand total of ~2 ppm…not the ~1 ppm I mentioned.

    Anyway, I’m still interested in Roger Pielke’s opinion (or anyone else’s) whether it is worth hundreds of billions of dollars (or even tens of billions of dollars), to reduce the CO2 atmospheric concentration increase over the next decade by approximately 2 ppm (either by reductions in emissions, or by sucking the CO2 out of the atmosphere, such as with ocean iron fertilization).

    I can’t see how either method for reducing the increase in CO2 concentration makes “good policy sense,” as Roger claimed in his point #2.

    And that’s for the ***U.S.***. I think it makes even less sense for India, China, and the rest of the developing world. As the last one-third of Roger’s article notes, India, China, and the rest of the developing world want to INCREASE their energy usage, as part of their drive to become more wealthy.

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19. Charles Says:
    March 15th, 2006 at 9:19 am

    I too am interested in Roger’s response to Mark’s questions?

    Which of Mark’s policy options make sense (if any)?

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20. Mark Bahner Says:
    March 16th, 2006 at 10:20 am

    Charles writes,

    “I too am interested in Roger’s response to Mark’s questions?

    Which of Mark’s policy options make sense (if any)?”

    Charles, it looks like Roger Pielke Jr. isn’t going to answer my questions. I hope you realize the degree of pressure put on every researcher in the “climate change” field to avoid making the politically incorrect observation that, at present, evidence is pretty strong that the costs of reducing CO2 emissions simply don’t exceed the benefits of those reduced CO2 emissions.

    Roger Pielke Jr. at least makes the point very forcefully with respect to reducing CO2 emissions and reducing hurricane strengths. That he is not willing to go any further out on a political limb is disappointing, but not surprising. Very few people in the “climate change community” are willing to go anywhere near as far out on the limb as even Dr. Pielke. His description of the reactions to his search for truth regarding CO2 emissions and hurricanes strengths I think is evidence enough of why he is apparently willing to go no further.

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21. Roger Pielke, Jr. Says:
    March 16th, 2006 at 3:48 pm

    Mark-

    You are of course free to speculate as you wish about my motivations etc. Alternatively you could just read my views on the issues. Your questions are leading questions of the “are you still beating your spouse” variety. I’m not answering them because I completely reject the premises on which they are based and how you’ve framed the issue.

    If you want to understand my views on GHG policies, then have a look at my collaborations with Dan Sarewitz in The Atlantic Monthly, Issues in Science and Technology, and The New Republic. If you don’t find answers to your questions there, it is simply because I think they are the wrong questions.

    Thanks!

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22. Mark Bahner Says:
    March 16th, 2006 at 9:26 pm

    Roger-

    You write, “If you don’t find answers to your questions there, it is simply because I think they are the wrong questions.”

    In this blog post, you wrote, “2. Greenhouse gas reductions make good policy sense.”

    I asked you–specifically ignoring methane, and dealing only with CO2–WHY CO2 reductions make “good policy sense.” You’ve never answered. (And I can’t see the answer in your writings…as I mentioned, your writing even clearly describes how people in India are trying to use MORE energy…they don’t care about limiting CO2 emissions. Your writing also mentions how the Russians–quite logically!–think a warmer, CO2-enriched world would be BETTER for them.)

    You also write, “Your questions are leading questions of the “are you still beating your spouse” variety. I’m not answering them because I completely reject the premises on which they are based…”

    I don’t see how my questions can be regarded as being of the “are you still beating your spouse” variety…I’m certainly not calling into question your honor. If you “reject the premises” why not simply tell me which premises you reject?

    For example, I estimate the cost of the U.S. reducing its CO2 emissions by 20% at $70-100 billion per year. If you think that’s way too high (or way too low), why not simply respond that you think my estimate is too high (or too low)?

    I further estimated the costs of removing an equivalent amount of CO2 from the atmosphere using iron fertilization at about 1/10th that amount. If you think that’s way too low (or too high), why not simply respond that you think my estimate is too high or too low? (Or if you think that action would or could create some massive new problem, why not just say so?)

    Finally, I asked IF a hurricane reduction system could be designed that would reduce the strength of hurricanes reaching landfall by 2 Saffir-Simpson categories at a cost of $70-100 billion, would that make good policy sense? If you think the actual cost would be 10 times or 100 times higher, why not just say so? Or if you think the “cure would probably be worse than the disease,” why not simply say so?

    Best wishes,
    Mark

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23. Roger Pielke Jr. Says:
    March 16th, 2006 at 10:03 pm

    Mark-

    1. The most effective ways to reduce GHG emissions in my view are through so-called no-regrets options. No-regrets options are not justified as you have framed the question.

    2. See my post on Air Capture.

    3. Weather modification of hurricanes? Been there, tried that. Not a good idea for legal, ethical, scientific reasons. Cure worse than disease for sure.

    Thanks!

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24. Douglas Hoyt Says:
    March 17th, 2006 at 4:00 pm

    Roger,
    Do “no regrets options” or no regret policies” really exist? If you have to invoke a policy, then you are forcing someone to do something (such as spending money) which they would not otherwise do. It is not “no regrets” for the ones being forced.

    If there is a policy, there is always some group that will regret it. Perhaps a “no regrets policy” is simply one that gives no regrets to the people proposing it.

    In any case, “no regrets policy” seems like an oxymoron, like a “harmless knife”.

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25. Dano Says:
    March 17th, 2006 at 5:17 pm

    Ah yes, but Doug knives don’t cut people, people cut people.

    In any case, “no regrets” policy is a construct of the Bush I administration:

    http://ncseonline.org/NLE/CRSreports/climate/clim-17.cfm#_1_7

    and used to be invoked by many conservative think-tanks, viz:

    http://www.rff.org/Documents/RFF-Resources-130-climate.pdf
    http://www.hooverpress.org/productdetails.cfm?PC=895

    Best,

    D

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26. Douglas Hoyt Says:
    March 17th, 2006 at 7:01 pm

    Just for the record, the earliest mention of a “no regrets policy” that I am aware of is
    White, R. M., The great climate debate, Scientific American, July, 1990.

    The idea seems to have been around earlier, but without the catchy phrase.

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27. Mark Bahner Says:
    March 17th, 2006 at 9:34 pm

    Hi Roger,

    I appreciate your answers. Unfortunately…

    1) Could you answer directly my question of why it makes “good policy sense” to reduce CO2 emissions? In your opinion, what significant problem or problems does CO2 cause?

    2) Regarding “no regrets”…do you really think that there are sufficient “no regrets” policies to reduce U.S. emissions of CO2 emissions by approximately 20 percent in the next 5 years or so? If so, what are they?

    3) Regarding your post on air capture…I remember you like air capture using CO2 removal towers. (Despite the fact that it will be tremendously expensive, and the warning of the researchers that the towers might damage vegetation downwind of the towers.) Do you like CO2 removal using ocean iron fertilization just as well?

    4) I presume your reference to “been there done that” regarding hurricane reduction is in reference to Project Stormfury? If so, do you know whether Project Stormfury was preceeded by a year or more of multiple conferences (hopefully even international) that looked at dozens or even hundreds of different methods of hurricane reduction?

    Regarding the cure being definitely worse than the disease, do you have an estimate of what is the difference between the net present value cost for all hurricanes for the next 40 years, versus the NPV cost for all hurricanes, if they’re reduced by 2 Saffir-Simpson categories?

    Or, to look at it another way, can you estimate the savings that would have occurred over the past 40 years, if all hurricanes that struck the U.S. had been reduced by 2 Saffir-Simpson categories?

    My guess is that the “disease” involves a pretty hefty chunk of change. (Not to mention the 1000+ lives that would have been saved by reducing hurricane Katrina alone by 2 Saffir-Simpson categories.) I suspect that most of the residents of New Orleans and Homestead FL would probably disagree that the cure would be worse than the disease.

    Best wishes,
    Mark

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28. Roger Pielke Jr. Says:
    March 17th, 2006 at 9:51 pm

    Douglas-

    “No regrets” was a phrase invoked by Bush I, see, e.g.,

    Reilly, W.K., 1990. What we can do. EPA Journal 32.

    But was really implemented to some positive effect under Clinton/Gore, see, e.g.,

    http://sciencepolicy.colorado.edu/about_us/meet_us/bklein/pdf/1999.17.pdf

    The reality is that actual progress has been made on “no regrets” policies, see this discussion of the work of Michele Betsill:

    http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000437more_cart_and_horse.html

    “no regrets” policies are often called “win-win” and have a long and successful history in the environmental movement. CFC policy history is a case study in the success of no regrets policy options.

    Thanks!

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29. Roger Pielke Jr. Says:
    March 17th, 2006 at 10:03 pm

    Mark-

    Some replies:

    1) There are many policies than make sense for other reasons that have the effect of reducing GHG emissions, see discussion of “no regrets.” In addition, GHGs affect the climate system in ways that create risks for things that people value. In such a situation we should seek to reduce those risks whenever possible.

    2) Five years? I doubt it. Short of economic collapse a la former Soviet Union I don’t see any policy that can have such an effect. Nonetheless, I think that the greatest postential for successful reduction of GHG emissions lies in “no regrets” options.

    3) You have mischaracterized my perspective on air capture. I simply argued that it should be studied far more intensively than it is currently. I am pretty dubious of iron fertilization from the standpoint of unintended consequences.

    4) On hurricane modification, there are two issues worth raising here. One is the impracticality of actually modulating storm intensities. The second is that hurricanes bring benefits (e.g., rainfall, part of ecosystem functioning) as well as costs. You can speculate all you want about costs/benefits of hurricane modification, but recognize that there is no consensus that it is possible or even desirable.

    Thanks!

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30. Mark Bahner Says:
    March 18th, 2006 at 10:16 am

    Hi Roger,

    You write,

    1) “…In addition, GHGs affect the climate system in ways that create risks for things that people value. In such a situation we should seek to reduce those risks whenever possible.”

    “2) Five years? I doubt it. Short of economic collapse a la former Soviet Union I don’t see any policy that can have such an effect. Nonetheless, I think that the greatest postential for successful reduction of GHG emissions lies in “no regrets” options.”

    But just how much emissions reduction are you expecting from the “no regrets” options that you advocate.

    I’ve pointed out that a (whopping) 20% reduction in U.S. emissions, done immediately, and continued for an entire decade, produces only an approximately 2 ppm reduction in atmospheric concentration in a decade. (The reasoning behind that calculation is as follows: it takes approximately 1.8 gigatons as carbon–or 6.6 gigatons of CO2–to produce 1 ppm of change in atmospheric carbon dioxide concentration.)

    Let’s (generously) say your “no regrets” policies result in an immediate 5% drop in U.S. emissions, relative to what they are now, and that 5% drop relative to “business as usual” is carried on throughout an entire decade. We’re talking about only approximately a 0.5 ppm of CO2, relative to where we would be with “business as usual.”

    (Feel free to disagree with my calculations…I’m too lazy to rigorously check them.)

    If there is indeed such a small difference between the atmospheric concentration that would occur if the U.S. followed a “no regrets” policy, and the atmospheric concentration that would occur under “business as usual,” as a PRACTICAL matter, your “no regrets” “reductions” are not really meaningful reductions.

    “3) You have mischaracterized my perspective on air capture. I simply argued that it should be studied far more intensively than it is currently. I am pretty dubious of iron fertilization from the standpoint of unintended consequences.”

    I think the reason air capture is not studied more than it is currently is that everyone can pretty much see that it will be fantastically expensive. Suppose we want to reduce tropospheric ozone (smog) concentrations in Los Angeles, or Boulder, or any other city. Does it make more sense capture the pollutants in the smokestacks (e.g., with fabric filters and scrubbers) or exhaust pipes (e.g., with catalytic converters), or does it make more sense to suck all the air in the city through giant air cleaning devices? The answer is the former, obviously.

    Regarding ocean iron fertilization, I definitely agree that unintended consequences are certainly possible (starting with the fact that more CO2 in the atmosphere may be a net BENEFIT, not a net problem). But it definitely has the low-cost potential that buidling large CO2 capture towers will never have.

    4″) On hurricane modification, there are two issues worth raising here. One is the impracticality of actually modulating storm intensities. The second is that hurricanes bring benefits (e.g., rainfall, part of ecosystem functioning) as well as costs. You can speculate all you want about costs/benefits of hurricane modification, but recognize that there is no consensus that it is possible or even desirable.”

    In 1925, what would you say would have been the scientific consensus regarding the possibility of a single bomb destroying an entire major city (e.g. Hiroshima and Nagasaki)? Do you think that in 1925, such an idea would be considered anything but completely impractical…a mere fantasy/nightmare?

    Similarly, in 1949…what would you say would have been the scientific consensus regarding the possibility of sending humans to the moon and back within 20 years? That probably seemed pretty impractical in 1949, don’t you think?

    Regarding the benefits of hurricanes…I totally agree that the benefits should be considered extensively. (In fact, my proposal is definitely NOT to eliminate hurricanes entirely…merely to make sure they are almost all Category 1 or 2…with only an occasional Category 3, and no Category 4 or 5 storms.)

    How about this for a public policy recommendation…do you agreee with me that the study funds you propose for land-based CO2 capture would be better spent on researching hurricane reduction methods (most definitely including exhaustive study of the possible unwanted side effects of such systems)?

    I think that if you look at the economic costs and benefits of reducing all landfalling hurricanes by 2 Saffir-Simpson categories, versus the economic costs and benefits of sucking say, 50 ppm of CO2 out of the atmosphere with CO2 air capture, the benefit/cost ratio is clearly in favor of the hurricane reduction concept, versus land-based CO2 capture.