Friday, December 22, 2006

Global Warming: Confusing Moral and Practical Arguments

In controversies over global warming, one issue that keeps coming up is whether it is anthropogenic, whether if the world is getting warmer it is our fault. So far as I can tell, the question stated in that way is almost entirely irrelevant to the controvery; it reflects a confusion between moral and practical arguments.

Suppose the cause of global warming is not human action but changes in solar activity or some other external factor. Suppose also that the consequences of global warming will be catastrophic. Finally suppose that there is something we can do to prevent global warming, say raising the albedo of the earth with orbital mirrors, high altitude pollution, or whatever. Isn't the argument for doing it precisely the same as if we were causing the warming? Hence isn't "whose fault is it" a wholly irrelevant distraction?

Of course, the questions of causation and prevention are not unrelated. If we are causing global warming that suggests one possible way of preventing it—stop whatever we are doing that causes it. But doing that may be, indeed very likely is, enormously costly, perhaps more costly than letting global warming happen. It might even be impossible, if what we have already done is enough to cause long run catastrophe even if we don't do any more of it. And even if we are causing it and could stop doing so, there might be better solutions.

Concerning Global Warming More Generally

I should add that I am taking no position here on the other usual questions about global warming. I do not know if it is happening, although it seems likely enough. I do not know if, if it is happening, it is due to human action, although that again seems a plausible enough guess. And it is not all clear to me that, if it happens, it will be a bad thing, let alone a catastrophe.

The crucial fact for me is that the more persuasive predictions of bad effects are well into the future; at one point the estimate was a sea level rise of half a meter to a meter over the next century. In my view, the next century is sufficiently uncertain so that it makes little sense to take expensive precautions against risks that far off. By the time the risk arrives, if it arrives, we may have already wiped outselves out in some other way. If we have not wiped ourselves out, our lives may have changed in a way that eliminates or even reverses the problem; communting via virtual reality produces little CO2. If we are still around and the problem is still around, we are likely to have a level of technology and wealth that will make possible a range of solutions well beyond what we are currently considering.

All of these are reasons why I think a persuasive case for doing something about global warming requires evidence, not yet available, of serious negative effects in the fairly near future. But that conclusion does not depend on whether whatever is happening to the climate is or is not our fault.


At 2:50 PM, December 22, 2006, Blogger Old Fartlek said...

Given your hesitancy to make any kind of argument I would suggest yhat you look up some factual evidence. For instance, the melting of glaciation almost worldwide that appears to be accelerating is a most scary effect of the warming trend.South American mountains, the Himalayas, our own northwest peaks, all are melting faster and faster. The impact won't be a century from now, but within 10 to 20 years.

At 5:48 PM, December 22, 2006, Blogger Beau said...

I appreciate this post because you articulate the many conflicting and confusing questions that arise as they relate to global warming. I have a recent post on the global warming issue as well, and I will edit it to include a link to your post here.

At 8:33 PM, December 22, 2006, Blogger Tim Lambert said...

If the warming is natural there is no reason to expect it continue. In fact, you would expect cooling as temperatures return to past levels.

Man-made warming otoh is expected to continue as emissions continue.

So, it makes a huge difference to what actions are required.

At 3:44 AM, December 23, 2006, Anonymous David said...

I think your presentation of the problem is way to simplistic. I don't really know where to start, so I'll just point out a few things.

The questions of causation is (on moral grounds) incredibly important. If global warming is caused by humans, then right now it is to a huge fraction caused by the developed world and to a very tiny fraction by lets say Africa (at this point). As you point out rightly, we (the developed world) will most likely be easily capable to deal with the consequences of global warming because we are rich and can afford it. Africa can't, at this point. Now, some optimists believe everything will turn out great and in a 100 years Africa will be rich as well, but really we don't know. So, lets assume for a second that some action by a person in a rich country today has the following effects: He/she will gain something now (heating, for his/her home, lets say), will suffer some damage in the future (the need to build a dike to protect against sea-level rise) which is lower than the gain he/she has today, plus some poor souls in Africa in 100 years will suffer damages and won't be able to deal with them at all because they are poor. Wouldn't you think that one would evaluate this very differntly from a moral point of view than a situation where global warming is caused by some natural variability?

Ok, next point. It doesn't make any sense to argue with the timing of risk. I.e. to say that risks that are further away should receive less wight. If a risk lies further in the future, we probably know less, i.e. the uncertainty is higher, i.e. the risk premium is different and we are done with it. Background risk of extinction for other reasons is also included in all economic predictions of climate change I know, just look at the discount rates they use. It is important that almost ALL of these studies (take a look at Nordhaus for the most prominent) suggest that a carbon tax would be appropriate, AFTER they have accounted for the facts you think had to be sorted out before any action should be done.

Another point: You seem to be under the impression that this is a fairly linear problem of a flow pollutant (maybe I am misreading you, but that seems to be suggested when you say that one way to stop global warming is to stop doing what caused it so far). It is a stock pollution problem, it is highly non-linear (the physics, I mean) and that makes everything a lot more tricky.

And finally. Lets look at your guiding principle "lets only care about things that have bad consequences in the near future". Is that a good principle for lets say a situation where you build up a stock of some physical substances today that will then trigger a catastrophe in 100 years? That can't be dealt with via new technology? If we would follow your principle, even if the cost of avoiding this would be very, very low, we wouldn't do it, because the bad is so far off. But that is crazy, isn't it? Shouldn't we just properly discount, apply risk premiums etc to such a problem and do a simple cost-benefit analysis? I never understand people that argue in such a principled way that seems to leave no room for concrete quantitative decision rules.

At 4:19 AM, December 23, 2006, Anonymous paul said...

Thank you for the post. Nicely put. I think it articulates my own thoughts on the subject very well. And since I think you are a reasonable person, it confirms my belief in my own reasonableness. I would bet heavily on the human race surviving climate change. It’s the other “black swans” the worry me.

At 9:30 AM, December 23, 2006, Blogger Lester Hunt said...

"I think your presentation of the problem is way to simplistic."

Some important truths are simple. Here's one: human affairs are at least as difficult to predict, especially in the long term, as are massive changes in nature. Arguments that we need to accept staggeringly huge costs, now, to forestall even worse catastrophes in the future, require that we be pretty darn good at making predictions in both realms.

But then distrust of one's own powers of prediction is a problem that global warming alarmists never seem to have.

At 12:01 PM, December 23, 2006, Anonymous Anonymous said...

Am I the only one who finds David's comment on the discount rate inchoate? David, could you articulate your point in clearer language?

At 12:07 PM, December 23, 2006, Anonymous David said...

I never said that we should accept huge costs now. All I said is that we should engage in a cost-benefit analysis and not come with simple arguments that we shouldn't do anything ever about things that are far away in the future.

Of course there are enormous uncertainties with any question like climate change. But instead of saying "there are uncertainties, so we can't answer the question", I suggest that you read up on the economic climate change literature. The active economists in that field are well aware of that problem, and they are using the well tested tools of economic analysis on how to deal with risk to tackle that problem. Now, they might make mistakes, but then point out those. I just don't see any value in statements like "There is risk, lets forget about this problem", when others are already attempting to deal properly with that risk in their calculations.

And a final note: If you suggest to do nothing about global warming you are implicitly assuming that there is a probability of 1 that nothing will happen. Given current knowledge, that is just not defendable at all. Of course, asking for very rapid huge emission reductions today is equally unjustified. But guess what, there is a middle ground, it can (and is) calculated and that is the sensible position. Not one of the extremes "Do nothing" or "Stop everything".

At 12:15 PM, December 23, 2006, Anonymous David said...

One more point: Those that argue here that nothing should be done seem to be under the impression that those that want action against global warming are ignoring the possibility that humans through technological and other progress will be able to adapt to damages from climate change. But gee, read the literature on economic climate change studies: Most have very optimistic assumptions about the adaptive capacity of societies. They DO include that aspect in their calculations. They still end up with a net damage from CO2 emissions in the end.

At 12:15 PM, December 23, 2006, Blogger LetMeSpellItOutForYou said...

If the warming is natural there is no reason to expect it continue. That's simply not true, since the Earth has long experienced wild climate swings.

At 1:43 PM, December 23, 2006, Anonymous Silulesa said...

If global warming is happening, and if it is bad for mankind, then:

(1) If it is not caused by humans, then

(1.1) Perhaps there's nothing we can do to prevent it, because the power of nature is much stronger than ours. It seems that nature simply doesn't want us here anymore. We should accept it and resign. By the way, who told us that Earth was made as a place for us to live in? And if the end of mankind is inevitable, I see no sense in postponing it in 20 or 25 years.

(1.2) Perhaps we can prevent it and save mankind. Cost-benefit analisys.

(2) Now, if it is caused by humans, then

(2.1) Even if we have the power to, we should not prevent or stop it, because, definitely, humans don't deserve the planet the live in. Mankind makes this world and life very unfair. I think that, in this case, human race should exterminate itself, just letting it go.
Don't you think that I am destroying nature. After the end of mankind, nature would just keep its pace; some other species might disapear too, but new species would normally pop up as time goes by. Nature wouldn't change a bit!

At 4:21 PM, December 23, 2006, Blogger Scott said...

In controversies over global warming, one issue that keeps coming up is whether it is anthropogenic, whether if the world is getting warmer it is our fault. So far as I can tell, the question stated in that way is almost entirely irrelevant to the controvery; it reflects a confusion between moral and practical arguments.

This is a confusing introduction. You start by referring to multiple controversies, but by the next sentence have whittled it down to one. Which controversy are you speaking of? If you're speaking as to whether or not global warming is occurring, then whether or not it's anthropogenic is indeed irrelevant. But that's too obvious a point to be making.

Thus, I take it the controversy you are referring to is "What should we do about global warming (if it is occurring)?" But as to that question, of course whether or not it's anthropogenic is relevant--causation (or the lack thereof) is an integral part of what morality requires, and what morality requires guides our actions.

Consider your statement transposed to a different scenario:

"In the controversy over why this man is dead, one issue that keeps coming up is whether he died of natural causes or whether some guy killed him. So far as I can tell, that question is almost entirely irrelevant to the controversy."

My guess is you are adopting a pure utilitarian approach--principled morality, and thus causation, and thus anthropogenic warming, doesn't matter under this metric. All that matters is whether utility increases or decreases (this simplifies the issue. Utilitarianism requires it's own set of morality, just a radically different one from most legal systems).

But you are not a utilitarian, and should know better.

At 4:36 PM, December 23, 2006, Anonymous Mark said...

Wouldn't the truly free market solution to global warming's effects be for the injured parties to sue the parties who are causing the injury? Shouldn't someone living on a low-lying island, say, be able to sue the big polluters whom they believe are causing the sea level to rise? If such a suit went to trial, it seems that the issue of who is causing what isn't irrelevant at all.

At 2:14 AM, December 24, 2006, Anonymous David said...

I don't believe any of the normal free market solutions can work for global warming (if we accept for a moment that the phenomen exists).

The two solutions that would be text book free market are: 1) assign property rights or 2) rely on the Coarse Theorem.

1) is essentially what you suggest, i.e. the possibility of victims to sue those that emit.

2) would rely on the fact that loosers could offer incentives to those that emit in order to get them to emit less, and as Coarse has shown, that can lead to an efficient solution.

I think both break down due to the transaction costs involved. Anyone damaged would need to sue everyone who ever emitted CO2 (or offer compensation to everyone who emits CO2). Global warming is the text book case of a public bad with a huge number of participants. So, I think once you factor in transaction costs, the only plausible way to achieve an efficient solution is either by a Pigou tax or a permit trading scheme.

At 10:35 AM, December 24, 2006, Anonymous Anonymous said...

For anyone reading this blog:

I have been trying to make another post, but Google, which has apparently just introduced a new version of its software without warning, refuses to let me. When I try to sign it it refreshes the signin page. When I ask about that it tells me to enable cookies on my browser. Cookies are enabled on my browser.

David Friedman (it also won't let me comment as myself)

So it may be a while before I get a new post up.

At 1:42 AM, December 25, 2006, Blogger Internet-Marketing said...


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At 10:43 PM, December 25, 2006, Blogger Russell said...

David says "All I said is that we should engage in a cost-benefit analysis and not come with simple arguments that we shouldn't do anything ever about things that are far away in the future."

But that's exactly what DDFR has done. He's said that we can't compute the benefits for a century in advance, thus we have no reason to spend any money to gain those benefits.

At 1:33 AM, December 26, 2006, Anonymous David said...

No, that is not what he has done. What he did is more like "we can't compute the benefits for a century in advance, thus we assume they are 0". But that is even worse than trying to compute them, because we can be very, very sure that 0 is actually NOT what the damages from climate change will be. Now, of course there is a great danger to pick too stringent targets and cause great harm to economic growth by doing so (and as an aside, I think that danger is very real these days). But, the right answer to that is to sit down and calculate the damage to the best of our knowledge, factor in appropriate risk premiums and argue for that, not to end up in the other extreme corner and ask that we do nothing. Friedman seems to be in the latter camp, while Nordhaus (I'll stick with him as my example of an economist who is doing good work in that area) seems to look for the proper middle ground.

By the way: The work of lets say Nordhaus and the rest of the economic climate change community tends to suggest much lower emission reductions than what environmental groups or some of the politicised natural scientists argue for (or, to be more precise, the economists argue for lower emission reductions now, but very strict ones later, in order to give the capital structure time to adjust). The economists in this field can hardly be accused of being "alarmists" (make Stern an exception). But NONE of them ends up in the extreme position Friedman seems to suggest to wait longer before doing anything. They all calculate modest measures now that will get more stringent with time.

That result is of course sensible from two points of view: 1) It doesn't destroy a large number of the capital invested today over night and 2) if we find out in 10 years that the calculations were all wrong the damage done is a lot less severe than if we had done drastic things today.

So, again, my point: Saying to stop emitting CO2 today and saying to do nothing today are not sensible positions to take on this issue. The correct approach is to engange in proper cost-benefit analysis and then see what the conclusions are. Which is done, and those conclusions are not what Friedman seems to suggest.

At 11:04 AM, December 26, 2006, Blogger David Friedman said...

"What he did is more like "we can't compute the benefits for a century in advance, thus we assume they are 0". ... the right answer to that is to sit down and calculate the damage to the best of our knowledge, factor in appropriate risk premiums and argue for that"

There are two points of my argument that you are missing:

1. Over time, our information will improve. We are getting better at climate modeling, we will have more data, we will know more about what the future will be like as we get closer to it, and we will know more about what technologies we will have to deal with the problem. Insofar as the predicted costs are far in the future, it makes more sense to wait before deciding how to deal with them, even though the optimal full information solution would presumably involving doing some things immediately.

2. Not only do we not know the magnitude of the problem, we don't even know the sign. Consider the somewhat analogous issue of population. In the 1930's, the problem serious thinkers were worried about was underpopulation. In the 70's it was over population. A number of people in developed countries, with NRR will below replacement level, are now again worrying about underpopulation.

In the case of climate, we don't have very good models, we don't know for certain that there isn't an ice age looming in the near future, although it seems unlikely, and we don't know even the sign of the effects of human action over the next century--pollutants, for instance, can raise the albedo. So we could find ourselves doing expensive things that push in the wrong direction.

At 1:52 PM, December 26, 2006, Blogger Unnr said...

I think the population example is A) a really good one, and B) not indicating what you suggest it is!

Even in mid 1900s world population was growing alarmingly... Underpopulation was a local problem (as it still is). The issue is really thorny because we would all rather that "we" make relative gains in population. Maybe because of some unpleasant nastiness, maybe just because we genuinely think the world would be better off with more smart people and fewer dumb people ('course no-one assumes they're in the dumb category)

We may not know the specifics of Climate change, but it is becoming untenable to argue it's non-existence. Where I live, anyway, you'd definitely have to be dumb or locked in a box to ignore it, it's very evident that there has been change within everyone's lifetime... greater change over longer lives, but even a 20 year old remembers different weather patterns.

LOCALLY, in a few year period, or a few kilometer radius, things can look confusing. Back up and things clarify themselfs. The issue is thorny because we here are making the worst decisions and have the most to change.

Forrest for the trees.


At 6:32 PM, December 26, 2006, Anonymous David Gillies said...

From an economic standpoint, it obviously makes no difference whether global warming (if it is indeed occurring) is anthropogenic or not. To draw a distinction strikes me as being essentially a Leftist standpoint, inasmuch as Left-oriented arguments are characterised by the motivationalist stance whereas classical Liberalism tends to be grounded in the consequentialist (q.v. Arnold Kling).

What seems to be undeniable is that econometric models of the efforts necessary to ameliorate climate change suffer even more from the effects of parametric sensitivity than the General Circulation Models used to predict the warming itself. By altering just two parameters, the discount rate and the calculation of intergenerational equity (IGE), you can pretty much drive your model to any part of town you want.

As one of the commenters said, the laissez faire approach is probably some sort of Coasean taxation, presumably via Pigouvian taxes disbursed to the injured parties. But the free parameters of discount rate and IGE necessarily affect at what level and under what regime these taxes should be levied. I don't think anyone has a truly defensible case for setting them at any given rate. The problem may well be intractable.

At 7:40 PM, December 26, 2006, Blogger Steve Sailer said...

Excellent points

At 12:28 AM, December 30, 2006, Anonymous Anonymous said...

I understand your intro, though others may not, and I agree: mixing ethics into the argument is an unnecessary distraction. Whether human or nature-influenced, the issue remains the same: global warming needs to be attended to. The controversy as to whether global warming (GW) is occurring due to human or natural causes is extremely important however. If you want to look at it from a "moral" standpoint, that is fine, but that assumes you are questioning whether GW is a good or bad thing. From posted research and ideas as to what GW will bring, I think many of us would agree that it is not something we would like to wake up to.

You say

“If we are causing global warming that suggests one possible way of preventing it—stop whatever we are doing that causes it”

Not so. Definitely not so. Let’s sub in the word “change” for “stop,” and the argument of this solution being “enormously costly” somewhat goes out the window. Furthermore, you suggest that even stopping what’s costing GW may be even more costly than GW itself. I have to raise the flag there: There are many theories (some I would deem quite substantive) as to what is causing GW. To change them would indeed change our way of life, but I believe this change would be far less than that caused by the end result of GW itself. The benefit of stopping or reversing or hindering GW would far outweigh the cost.

Final point: you can’t wait for all the lights on the street to be green before you go. I am convinced that action today would not be in such a completely wrong direction as to cause GW to increase; we know enough to have a initial correction to this problem. Thus, waiting until the risk becomes increasingly apparent is not a viable solution. By then the problem could have metastasized into something far worse, much more advanced than our technology could correct. The burden of current proof allows this to be a more sensible course of action.

At 12:59 PM, December 30, 2006, Blogger Francois Tremblay said...

I am a bit puzzled as to how a Market Anarchist can advocate taxation as an efficacious means of dealing with problems, and rejects the market. Have you gone to the dark side, Mr. Friedman?

At 11:47 AM, January 04, 2007, Anonymous Anonymous said...

The person that has dedicated his life to precisely this thinking is Bjorn Lomborg. This 5 minute video will sum his work up

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At 10:04 AM, March 25, 2007, Anonymous Brent said...

CO2 Markets, quotas, options, trading schemes, et al....are rediculous. The volcanos of the world produce MORE CO2 than us humans. The oceans produce yet even more than the volcanos. Are we going to charge them too?

The Earth might be warming, but the fact is that we are not resposible for it, get a grip. Trying to create an artificial market won't do anything....we might as well start conducting world trade in bottle caps, blue sand grains, and four leaf clovers for all the good it would do.

Markets are driven by supply and demand, throughout history. If you think you can use an artifically created "market" out of a political position and claims of false facts that humans are warming the planet to control world economics you are sorely mistaken.

Next thing you will want to go bomb the third world for not using solar power or cutting down thier OWN trees for firewood when the solar cells you insist they buy from the first world.

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At 2:19 PM, May 16, 2009, Blogger K said...

Thank you for this article. Morality issues is more or less new aspect of the "How to fightGlobal Warming" problem. Human EGO is a hard to change or convince thing .

Here is a link disapproving the point on volcanoes competing with humans in CO2 production.

At 8:41 AM, June 02, 2009, Blogger Anthony said...

David Gillies said...

From an economic standpoint, it obviously makes no difference whether global warming (if it is indeed occurring) is anthropogenic or not.
Actually, it does, because that potentially limits our possible responses. If global warming is caused 90% by human emission of CO2, certain responses are available which are not necessarily available if global warming is caused 10% by human actions.


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