David R. Henderson  

Henderson and Cochrane on Climate Policy

PRINT
Macron, economic nationalist... Stop Thinking Like a Tourist: ...
Climate change is often misunderstood as a package deal: If global warming is "real," both sides of the debate seem to assume, the climate lobby's policy agenda follows inexorably.

It does not. Climate policy advocates need to do a much better job of quantitatively analyzing economic costs and the actual, rather than symbolic, benefits of their policies. Skeptics would also do well to focus more attention on economic and policy analysis.

To arrive at a wise policy response, we first need to consider how much economic damage climate change will do. Current models struggle to come up with economic costs consummate [sic] with apocalyptic political rhetoric. Typical costs are well below 10% of gross domestic product in the year 2100 and beyond.


These are the opening paragraphs of David R. Henderson and John H. Cochrane, "Climate Change Isn't the End of the World," Wall Street Journal, July 31, 2017. By the way, "consummate" should be "commensurate." I don't know how I missed that.

The op/ed, unfortunately, is gated.


Comments and Sharing






COMMENTS (41 to date)
FCAJR writes:

See Scott Adams (Dilbert cartoonist). He has been making the same point as well.

h8 writes:

Ironically, you missed an ] on your [sic].

Very good point though, sad that it's gated but the opening paragraph on it's own is still a powerful statement

Jon Murphy writes:

[Comment removed. Please consult our comment policies and check your email for explanation.--Econlib Ed.]

Hazel Meade writes:

Excellent topic for discussion.
I think both side struggle to have a productive dialogue on this subject. The right tends to resort to dismissing the whole idea that humans are causing an impact on the climate, which means only the left is the only group proposing solutions - and unsurprisingly their preferred solutions conform to leftist ideological preconceptions. And then, in response, the right's denial seems to be based on a kind of acceptance that those solutions are the only ones.

We either reconstruct society in an alternative ecologically conscious fashion, cultural revolution and everything, or else, it's not happening, nothing to see here.

It would be far more productive if people on the right were to presuppose that global warming is real, and that humans are a significant cause of it, and then think seriously about what would actually be a reasonable set of policy responses.

For instance, I always like to note that if climate change is as dire as some of the climate activists claim, then we ought to be building nuclear power plants and a feverish pace. Yet this policy option is almost never seriously considered. The only alternatives are presumed to be solar and wind power, which are unlikely to supply enough electricity to power current electricity needs, which in turn leads to an insistence that humanity radically alter our cultures to a low-energy lifestyle, i.e. riding bicycles, do away with air conditioning, etc. A lot of people's belief that automobiles and air conditioning are evils can be traced to a belief that they are unsustainable from a climate change perspective - conveniently ignoring that there are alternatives which could supply sufficient energy that aren't being considered.

I will note that nuclear is just an example of this sort of thinking. I'm not arguing that nuclear would be a silver bullet, but that it illuminates the way that left-wing preconceptions dominate the debate of climate change because the right has effectively outed out of it by going into denial.

Fred Foldvary writes:

Uncompensated harmful pollution is an implicit subsidy to the firms and their customers, which like explicit subsidies, generates a deadweight loss. A pollution charge prevents this subsidy and DWL. Therefore, a "green tax shift," pollution charges that replace DWL taxes (on sales and income) provide a double benefit. If the reduction in emissions reduces the increase in climate change, that is a bonus. Thus market-based environmental policy will help, not hinder, the growth of output.

Thaomas writes:

@ Hazel Mead

their preferred solutions conform to leftist ideological preconceptions.

Since when is a carbon tax a "leftist" solution? What would a "non-leftist" solution look like?

if climate change is as dire as some of the climate activists claim, then we ought to be building nuclear power plants and a feverish pace.

This does not follow. We cannot prejudge which technologies will win out in an environment in which net CO2 emissions are taxed. That's what is wrong with direct subsidies to "green energy" and "clean" energy set asides. I, too, suspect that nuclear power will have big role, but there is only one way to find out.

BJH writes:

Great article.

Hazel Meade writes:

@Thaomas,
It's not, not very many people are advocating a carbon tax. This is an idea bandied about in libertarian circles, but it is not very popular with either Democrats or Republicans. The official policy of the Obama adminstration was to have the EPA regulate carbon emissions and impose caps. And don't even try to suggest a carbon tax to a mainstream Republican.


MikeW writes:

Excellent article! Very well written, and such a breath of fresh air to see these points, which go unstated most of the time.

Very good comments by Hazel Meade above, too. It has long bugged the heck out of me that global warming is supposed to be the most serious problem facing humanity -- an existential crisis -- and yet, by their actions the activists obviously think that nuclear power is a bigger threat than global warming. (There are some exceptions, of course, and I have a lot more respect for the activists who have come out in favor of nuclear power.)

MikeW writes:

By the way, if you go to the article through RealClearPolitics, you can see it even if you don't subscribe to the WSJ.

Andrew_FL writes:
Since when is a carbon tax a "leftist" solution?

Is this a real question? Um, since the beginning of time?

I don't think I should have to explain why a tax is a left wing policy. Really?

Douglas Ogesby writes:

The authors miss the fundamental issue underlying the enviro-rads hysteria about the apocalypse we face because of global warming. This has nothing to do with science. Rational debate is off the table because the deniers (read: Holocaust deniers) are right wing nut jobs. The enviro-rads' and their largely left wing Dem sycophants' objective is not saving the life as we know from imminent destruction. It is instead government control of the energy industry, energy intensive manufacturing and ultimately of the entire economy In a word, the alarmists' objective is totalitarianism.

Conor writes:

I think people on the Left view Global Warming as a sort "Open Sesame" for their policy preferences. Everyone not sharing those preferences has the choice of coming up with different solutions or simply denying the problem. To the extent those preferences seem to have anything to do with the underlying issue the former is easier but when the "solutions" are just naked asks it's easier to go for the later on the logic that "they're not taking the problem seriously so why should we?"


Lewis writes:

These estimates of costs and benefits are a joke. What if someone in 1917 had tried to estimate costs of climate change for 2017? He would probably have left out the green revolution and the massive population explosion it enabled. The UN's own predictions of sub-saharan african population display wild variance and unpredictable assumptions about what women will choose to do there in 2050.

You might say: "well we have to give it our best shot." No we don't. What matters here is that there is a non-trivial, but incalculable, existential threat. Planetary ecological destruction and mass displacement may have very small probabilities, but since their cost and probability is not reasonably calculable---beyond saying they are not out-of-the-question---standard benefit-cost analysis is not the right tool for this domain.

I think the thing to do is simply sharply curtail carbon emissions. It wouldn't entail a government takeover of the economy. What is less free about a country with, say, a higher gas tax and a lower payroll tax? There is no need to reconstruct society, just impose some more taxes and subsidies equal to a few percentage points of GDP. I have seen Denmark and Singapore at the top of those economics freedom indices for quite some time; and yet there carbon emissions are very low compared to ours.

I am not even convinced we would ave to raise to government's share of revenue substantially to pay for this. We can simply cut out lots of utterly useless spending by applying cost benefit analysis to domains where it is actually practical. Currently Medicare, Medicaid and other government health care plans pay many billions for drugs and treatments with little measurable improvement over placebo, and which might actually inflict harm. Read Sam Quinones new book on the opioid crisis, and you can see that Medicaid is basically financing the whole epidemic. A study of thousands of kid in Quebec found that Ritalin produces no benefit in children, and yet governments pay for this and other stimulants en masse. Every month there is a new "failure-to-replicate" finding for a common treatment.

What if our government, like the UK's, only paid for treatments that passed some cost-benefit analysis? That is a domain where we have real, short-term data in repeated situations and can collect more. If people want to get all these sham treatments, they can pay for them out-of-pocket. Then we could use the leftover revenue to subsidize low-emissions energy, vehicles and infrastructure.

This gets me because I work in a field, transportation engineering, where we do decade-long cost benefit analysis; and it is all clearly pseudoscience and always has been. So no, I don't think we need to grapple with the future costs of climate change; we need to just solve the problem using the massive resources already at our disposal. Worst case scenario is that we free ourselves of dependence on theocracies and make our country robust to geopolitical risk.

MikeP writes:

Since when is a carbon tax a "leftist" solution? What would a "non-leftist" solution look like?

Waiting 50 years while humanity gathers more information, technological capabilities, and wealth?

David R Henderson writes:

@h8,
Thanks. Fixed.

Dylan writes:

"Since when is a carbon tax a "leftist" solution?"

"Is this a real question? Um, since the beginning of time?

I don't think I should have to explain why a tax is a left wing policy. Really?"


---

At least with regards to climate change this really isn't true. 20 years ago when I was first learning about environmental economics ideas like "Cap and Trade" or a carbon tax were very big with economists, but were pretty much dismissed by most of the major environmental activists groups and those on the left in general as giving a "moral right to pay to pollute" and similar sentiments. That's been changing pretty steadily since then, and I'd say some form of a carbon tax now has pretty broad support from the center left to the center right among those that are concerned about global warming, but it certainly wasn't always that way.

Thaomas writes:

@ Mike P

Why wait only 50 years? Why not 100? :)

Seriously, Why not set a carbon tax according to our best guesses now and continually adjust it according to new data and modeling of the climate, economy and technology?

zeke5123 writes:

@Lewis

I think you are right, in the sense that predicting the future is incredibly difficult. See Black Swan. Thus, I agree with a precautionary principle. Interestingly enough, the same logic makes me somewhat skeptical of global warming claims (modeling climate is incredibly difficult and almost necessarily cannot accurately predict the future). Nevertheless, in the face of uncertainty, a certain degree of precaution is required.

The question is how much precaution. There are many existential risks (e.g., asteroids, AI, Nuclear North Korea, some viruses). How much do we spend on all of these risks as a pre-caution? At what risk to today's enjoyment? I don't think anyone has the answer, but... it is very difficult.

@Thamos

Doesn't that sound like a warped incentive? We already know there is a bit of publication bias / desire to influence policy in mainstream climate science. If you in good-faith believe global warming is a big problem, then maybe tweaking methods to drive a larger tax could happen if you know it will lead to less carbon.

MikeP writes:

Why wait only 50 years? Why not 100?

I offered 50 years because William Nordhaus uses 50 years when he runs his models. The cost of waiting 50 years before applying the optimal carbon tax is not strikingly greater than that of applying the optimal carbon tax today.

Seriously, Why not set a carbon tax according to our best guesses now and continually adjust it according to new data and modeling of the climate, economy and technology?

A carbon tax has very significant and completely uncounted costs. It requires new taxing legislation and authority. It places new revenue into the wildly inefficient hands of government, with little promise of trimming other taxes commensurately. If it is not administered with extreme strictness, it can become an endless font of rent seeking. And it carries the very real potential of generating carbon trade blocs around the world as differing carbon tax regimes try to properly account for the carbon consumed within them.

Is all this worth the ~$1 trillion net present cost of waiting 50 years -- i.e., less than $10 billion per year paid off over the next century? I don't think so. And if we find in 15 or 20 years that 50 years' delay really would cost too much, we can start carbon taxes then.

Gary Irwin writes:

I think the key point is the "insurance" question - but here I believe you got it wrong. If there is indeed a small probability of life as we know it ending, that puts us in the position of a "Pascal wager" and not for example in a situation like where a nuclear power plant might melt down which is simply a very large negative. Because there are sufficiently many (though not all that many of course) reasonable scientists who say there is a small probability of ending life as we know it, steps must be taken - especially when if we had a rational system, they would be not very hard: replace a large number of taxes with carbon taxes.

I like to think of it this way: I pay approximately .2% of my annual income for an umbrella insurance policy, we should be doing at least as much of our national income for climate change!

Brian writes:

"It would be far more productive if people on the right were to presuppose that global warming is real, and that humans are a significant cause of it, and then think seriously about what would actually be a reasonable set of policy responses."

Hazel,

Good suggestion. OK, global warming is real and humans are a significant cause. Now let me think seriously about what to do....

Well, global warming, human caused or not, is a slow-moving problem. It won't have any affect on me, most likely. Might affect my kids later in their lives. Worst of all, could devastate the kids and grandkids of people in very poor countries.

Best approach would seem to be pushing economic growth and innovation, especially in poor countries. That means we want to allocate resources as efficiently as possible right now. Remove regulations and other disincentives. Make as much energy as possible using the cheapest methods available. That would be fossil fuels mostly. (Yes, burn, baby, burn, at least for now.) Continue to fund research for alternative fuels so they'll be viable options 30 years down the road. Eliminate poverty around the world in 30 years. Achieve global affluence. The countries will be prepared to adapt to whatever climate change comes.

In other words, we can innovate our way out of whatever problems come. We have the time. So BAU seems to work with a special emphasis on free market-driven alleviation of poverty. Specific climate policies will only get in the way of achieving a true revolution for human good.

Hasdrubal writes:

@Hazel Meade

I think both side struggle to have a productive dialogue on this subject. The right tends to resort to dismissing the whole idea that humans are causing an impact on the climate, which means only the left is the only group proposing solutions - and unsurprisingly their preferred solutions conform to leftist ideological preconceptions. And then, in response, the right's denial seems to be based on a kind of acceptance that those solutions are the only ones.

I'm convinced that this is because the left has done a very good job of framing discussion of climate change around the assumption "If climate change, then these policies must be enacted." Look at how the concept is treated in the media, the gotcha question is always "do you believe in climate change?" That's either a yes or no, there's never any room for "yes, but...."

So the right has reacted by accepting the left's premise and simply denies climate change.

It's a great tactic by the left because they a.) get an easy win on the question that they want to debate along with the opportunity to snub those who disagree with them, and b.) get to avoid messy, nuanced policy discussions in favor of a simple yes/no question.

Thaomas writes:

@Brian I this yours is broadly the right approach. My query is, why not push technological change and current and present substitution among technologies and consumption and investment choices toward less net CO2 emitting activities with a carbon tax?

Mark Bahner writes:
The countries will be prepared to adapt to whatever climate change comes.

One important point that I think very few people appreciate: global warming is reversible. If during the 21st century the CO2 atmospheric concentration rises to 580 ppm, then in the 22nd century, they can reduce the CO2 level by 300 ppm, back to the pre-industrial CO2 concentration of ~280 ppm.

We have the technology to do that right now. It's simply a matter of cost. Let's run some numbers:

1) Per wonderful Wikipedia, present gross world product (GWP) is about $75 trillion.

2) If GWP grows by an average of 2.8% per year to the year 2100, the GWP is about $750 trillion.

3) If it costs $1000 per ton of CO2 to remove CO2 from the atmosphere and sequester it underground, the cost to remove 1 ppm of CO2 from the atmosphere would be about $7.8 trillion. So the cost to remove 300 ppm would be $2340 trillion. (Note: If the world did *massive* CO2 removal, the costs would almost certainly be less than $1000 per ton of CO2 removed and sequestered.)

3) If the world in 2100 spent 10 percent of it's GDP in 2100, that would be about $75 trillion per year. So they could remove 9.6 ppm per year, or 300 ppm in 31 years. By ~2130, the CO2 is back to the pre-industrial concentration of 280 ppm.

P.S. For perspective, the U.S. spent about 10 percent of its GDP on the military from 1944 to 1974. I don't think anyone would say that it was a time of great economic suffering.

Hazel Meade writes:

@Hasdrubal,

I agree, although it's hard to say weather the left just managed to frame the issue to their advantage, or the right simply allowed them to do so by opting out of the debate.

David Smith writes:

[Comment removed. Please consult our comment policies and check your email for explanation.--Econlib Ed.]

Brian writes:

Mark,

Yes, I think you're right. Working to increase wealth now allows the later fix, if needed, to be relatively inconsequential economically.

Perhaps some comparison to space travel is relevant. It wouldn't make sense to attempt interstellar travel this century with the technology we have (assuming it would even be possible) because by the next century, spacecraft would be so fast (presumably) that we could easily pass the spacecraft of the previous century. There will come a time when space travel makes a big enough leap and becomes sufficiently mature that interstellar travel might make sense; attempting it before then, even if technically possible, will not.

In other words, sometimes technology advances rapidly enough that it makes sense to wait until that time arrives. That's probably the case with global warming responses also.

Brian writes:

"My query is, why not push technological change and current and present substitution among technologies and consumption and investment choices toward less net CO2 emitting activities with a carbon tax?"

Thaomas,

If done solely for the sake of global warming, whose outcomes are still very uncertain, a carbon tax would favor technologies that are less than optimal for the current economy.

Now if there were another reason for reducing carbon that currently makes economic sense, a case can be made for a carbon tax. An example might be pollution reduction to avoid health costs, etc. And there's nothing wrong with letting global warming remediation tag along. I just don't see a current benefit to justify it. For example, if we had implemented a carbon tax 15 years ago (say Al Gore had become president), would we have had the fracking and natural gas revolution? Probably not, especially since Gore would also have pushed to ban fracking altogether. Using taxes and other policies to chose sub-optimal technologies is not the right approach to eradicating poverty and making the world as wealthy as possible.

Thaomas writes:

@ Brian

Yes any tax has a non-zero cost compered to a lump sum transfer. One would need to compare the difference in costs of the carbon tax with the taxes it replaces. With wage taxes these are not insignificant. Even general business income taxes are so exception ridden as to have high costs.

But of course, the whole point of a carbon tax IS to shift activities in ways to prevent more climate change.

@ others
I'm still having trouble with the idea that so many commentators see carbon taxation as "leftist" and marginal. To me this kind of a position:

http://www.robertstavinsblog.org/2017/07/31/environmental-economics-personal-perspective/

is pretty mainstream and not at all "leftist" unless everything except pure Libertarianism is "leftist."

Hazel Meade writes:

The one worry I have about a carbon tax is thatit would end up being used to raise general revenue. I'd were going to have a tax to mitigate the effects of global warming, the money should go into a fund that is exclusively used to compensate people who are harmed by warming linked climate change. Then the tax rate should be pegged to the outflows from that fund.

Mark Bahner writes:
If we're going to have a tax to mitigate the effects of global warming, the money should go into a fund that is exclusively used to compensate people who are harmed by warming linked climate change. Then the tax rate should be pegged to the outflows from that fund.

One problem with taxing CO2 and giving the money to people harmed by "climate change" is determining who is harmed by "climate change." For example, was California's recent drought a result of "climate change" or simply weather?

Another problem is that the people harmed can be well outside the U.S. So if it's a U.S. tax that compensates people outside the U.S., that will be tricky.

Also, any harm is not all caused by people in the U.S., or even people emitting CO2 now.

All of these problems can be greatly reduced if there is instead a tax on other pollutants that are co-emitted with CO2. For example, coal-fired power plants emit significant particulate matter. The effects of particulate matter are much more localized, and the health effects much more clear.

Similarly, coal-fired power plants, natural-gas-fired power plants, and automotive engines all emit nitrogen oxides (NOx) that contributes to tropospheric ozone ("smog") formation and acid rain. Those effects are more localized and easier to determine.

I don't think anyone I've ever had contact with who advocates for carbon taxes has agreed that other taxes (such as taxes on particulate matter emissions or NOx emissions) might be a good substitute for carbon taxes.

Andrew_FL writes:
I'm still having trouble with the idea that so many commentators see carbon taxation as "leftist"

Enlighten me, please, as to your theory of right wing taxation.

Brian writes:

"I'm still having trouble with the idea that so many commentators see carbon taxation as "leftist" and marginal."

Thaomas,

It looks like you have in mind a revenue-neutral carbon tax. I don't know for sure, but other posters might be thinking of a carbon tax as being an additional tax to raise more revenue. The latter would generally be viewed as left-wing, since (so the stereotype goes) people on the left have never seen a tax they don't like. But even with the revenue-neutral case, folks on the right would view such a tax as an attempt to control people's behavior, which is seen as a leftist (big government) thing to do. Policies that are heavy on signaling and control will tend to be viewed as leftist, justified or not.

Hazel Meade writes:

@Mark Bahner,

I agree, those are issues that need to be addressed.

I think in the case of acid rain and local particulate matter, we shouldn't even need a tax. Since the effects are local and easily traceable to a single source, with easily identifiable victims, that can be handled with standard liability.

The problem with carbon emissions is that the effect is globally dispersed, difficult to distinguish from natural weather variation, and impossible to attribute to a single culprit. That's why taxing all carbon emissions equally is a reasonable approach. I think that the global effect implies that the carbon tax ought to be applied globally as well - there would need to be an international treaty and all the monies would have to go into one pot. And then you have to have some mechanism to decide whether a particular incident is attributable to climate change or not, and if so how much money should be paid out to victims. Maybe the funding should be directed no so much to victim compensation as mitigation of gradual damages - i.e. funding for seawalls and relocation of coastal villages, etc.

The point is that the carbon tax shouldn't go into general revenue, because that will make it disconnected from the extent to which climate change is "real" and create a temptation to increase it to raise general revenue to spend more on unrelated projects. If it's tied directly to actual spending on global warming related problems then there will be limits on that happening. Actually putting it into a global fund might help prevent that. The US congress isn't going to want to finance development projects in China.

MikeP writes:

I'm still having trouble with the idea that so many commentators see carbon taxation as "leftist" and marginal.

It is not carbon taxation per se that is leftist: It is massive government intervention in society and economy as the solution to a perceived problem that is leftist.

Take, for example, Citizens' Climate Lobby. On the surface they sound rational and nonpartisan. But a quick tour of their website, specifically their Carbon Fee and Dividend plan, reveals their extreme leftist position.

CCL claims their carbon tax is "revenue-neutral". But they don't mean it offsets reductions in taxes elsewhere. Rather, they mean all the revenue is immediately redistributed equally to everyone. And then they have the gall to say this leftist proposal "bridges the partisan divide".

But that is not the worst part of the CCL carbon tax proposal. The worst part is that it would raise the per-ton tax $10 per year every year until CO2 production is driven down to 10% of 1990 levels. Every year. Passing the consensus social cost of carbon in 3 years, but not stopping. Regardless.

Anyone who has read their Nordhaus knows that aggressively targeting temperatures or levels rather than targeting social cost of carbon is impoverishing at an epic scale. Their proposal shows a phenomenal disregard of the economics and of humanity as a whole in the service of a wildly expensive environmental goal. Again, leftist.

Rich Berger writes:

Although your article was helpful in one sense, it failed to highlight the key issue: how credible are the predictions of apocalypse? So far I see a failure of predictions: actual temperature increases are at the low end of the model predictions. The instrumental record goes back to the late 19th century and shows warming and then cooling and then warming, with the entire trend consistent with a warm rebounding from a very cool period. The attempt to eliminate the medieval warm period (via Mann and his hockey stick) has suffered mortal blows due to selective use of tree proxies, splicing different data on in the 20th century when the trees don't show warming and suspect statistical tricks that yield hockey sticks from noise data. The entire scare rests on model projections of a very complex climate system and the models incorporate some very tendentious assumptions about the role of rising CO2 on temperatures. For example in 1988 James Hansen of NASA provided projections of temperature increases under various scenarios - as of recent years, he overshot actual temperatures by a wide margin.

Climate research suffers from group think where an orthodoxy about the effect of humans on climate must not be challenged (the science is settled). When EPA head Pruitt suggested a red team blue team approach as used in the military (dueling theories/models), the science establishment loudly protested. How likely is a contrary view to gain funding or avoid ostracism in the academy? If the science is settled, then where is the proof?

Climate science is a stalking horse for expanded control over our lives (no accident that the UN is a prime suspect) and they have their answer so the game is over. Finally, if the models are suspect in diagnosing the problem, how useful are they in finding a "solution"?

MikeP writes:

I'm still having trouble with the idea that so many commentators see carbon taxation as "leftist" and marginal.

In case the CCL example wasn't clear... A carbon tax that (a) is set to the social cost of carbon, (b) exactly replaces existing taxes, (c) can be avoided solely by Coasian offsets for equivalent sequestration, and (d) represents the entirety of government climate change policy with no other mandate, tax, or subsidy is the centrist and economically defensible carbon tax.

Any carbon tax that is more aggressive, or any government policy beyond the tax, even policies as simple as subsidies for electric cars, pushes the carbon taxation to the left. It could also be pushed toward the right, e.g., by subsidizing coal companies that would be harmed by the tax, but libertarians are not going to advocate those moves either.

In other words, commentators of a libertarian bent realize that advocating a carbon tax means that, while they may be taking the centrist position on carbon taxation, it is the most libertarian position possible on carbon taxation. There is no compromise or trade off from there against positions to the left. Hence it is a terrible ledge to start negotiations from.

Huy writes:

i believe that climate problems do exist in our world today due to pollution mostly from machines created by humans. The right and left sides of politics have different ways to deal with these pollutions. I personally believe that if we were to view this as economists, there's profit to be made if producers/inventors produce products that help make the planet "greener" Mass consumers usually want to buy products that go with trends and a popular trend today are eco-friendly products. Overall, most producers/businessman I believe doesn't really care about what happens to the planet, they see this idea as an opportunity for them to create new products that fit the current trend, which they will profit off of.

Daniel Artz writes:

It is not just the economic analysis of climate change that is wanting, it is also the science on causation. And many of the comments on this thread reveal a real blind spot on that - the almost universal assumption that if climate change is real, AND if human activities are responsible for some portion of the observed warming, the culprit MUST be CO2 emissions.

While there is robust evidence for a correlation between atmospheric concentrations of CO2 and surface temperatures, the evidence that it is the CO2 which causes the temperature increases, rather than the other way around, is much much weaker. Unfortunately, the funds which have been made available for research have focused almost exclusively on CO2, based on the assumption that it is the primary driver of higher temperatures. But Humans have been altering climate response in many other ways, and for much longer than the high levels of industrial emissions of CO2 have been around. We have radically changed the albedo of huge portions of the Earth's surface by land use changes - millions upon millions of acres of concrete and asphalt roadways, alleys, parking lots, airport runways and taxiways, loading docks, etc.; millions upon millions of acres of buildings covered with dark, heat absorbing composition shingles; billions of acres turned from forest and prairie into tilled agricultural land. Yet there is little or no research on just how these changes in the albedo of the surface from human driven land use changes affect atmospheric temperatures. I have seen rough calculations which indicate that the effects on temperature of land use changes (including the effects of carbon particulate pollution - soot - settling on sea ice and glaciers and accelerating warming and melting) may exceed any temperature effects of CO2 by a full order of magnitude or more. So, maybe climate change is real, AND caused (at least in part) by humans, but all of our policy proposals are directed at the wrong culprit.

CO2 is NOT a pollutant; it is in fact essential to all life on earth (well, all aerobic life). Green plants need it to conduct photosynthesis, and in fact grow faster, healthier, and more productively at atmospheric concentrations much higher than the current 400 ppm levels. So trying to reduce CO2 emissions IF it is not the principal, or even a meaningful, driver of climate change is not just a waste, it is counterproductive.

Mark Bahner writes:
I think in the case of acid rain and local particulate matter, we shouldn't even need a tax. Since the effects are local and easily traceable to a single source, with easily identifiable victims, that can be handled with standard liability.

I don't think it's as simple as that. Here's a map with satellite measurements of ambient concentrations of PM2.5 (particulate matter less than 2.5 micrometers in size). From sources like this and ambient monitoring networks, we have an idea what ambient concentration of PM2.5 are like. But it's difficult to attribute and apportion the measured concentrations to exact sources. Further, we know that there's a statistical correlation between high PM2.5 concentrations and human health effects (e.g. cardiovascular and respiratory disease) but it's difficult or impossible to attribute specific cases of disease to exposures to PM2.5.

So what we're really left with are general correlations. I don't think that situation is easily handled by standard liability. I think it's better handled by a tax on emissions. But on emissions of PM2.5 and tropospheric ozone (smog) precursors, where the effects are much more clear and spatially and temporally related to emissions than for CO2.

POST A COMMENT




Return to top