My views on global warming

1. It is by now pointless to deny that global warming is man-made to a considerable degree.

2. It is a very real problem.  If you don’t believe me, go visit the deltas of East Bengal or Bangladesh and think about it again.  Sweden I am not worried about and Greenland may become valuable, but where do we put the losers and no this isn’t just a few small islands in the Pacific.

3. I can imagine Manhattan and other major cities taking protective action against rising water levels, much as the Dutch do today.  I recall reading that the Dutch spend about as a high a percentage of their gdp defending themselves from water as the U.S. does on national defense.  That is quite a burden, but it is better than forsaking economic growth.

4. Like Arnold Kling, I do not much trust climate models.  Perhaps I have spent too much time doing macro, and the experience carries over.  Nonetheless uncertainty about final effects gives us more to worry about, not less.  It is the worst-case scenarios for global warming which worry me, not the middling scenarios.  Variance is our enemy in this matter.

5. I don’t have a good plan for what to do.  Imagine passing and extending Kyoto and turning 2/3 of the U.S. energy supply into nuclear, wind, and solar power.  Heroic achievements, to be sure.  But if China and India continue to industrialize, global warming will likely continue and perhaps accelerate, as I understand current knowledge.

6. I have yet to see a real plan which recognizes three points: a) without continued economic growth the world will probably fall apart, b) the problem is real and significant, c) any good preventive solution would require an enormous amount of concerted action across both time and across nations.

7. How much does the framing of the problem contribute to our political views on the matter?  How much would we spend, or how intensively would we organize global action, if a typhoon were headed right for Bangladesh?  An earthquake?  A war?  A much slower set of changes, not fully our fault?  An out-of-control American nuclear weapon?  Should it matter?

8. If we could relocate all the losers-to-be into freer and richer countries, should we consider this a satisfactory solution?  Or are we still massive and unjustified aggressors if they are crying to us: "Don’t let it happen, don’t let it happen!"?


How do you account for the Medieval Warm Period? What happened to the glaciers that covered the midwest just 10,000 years ago? Why did the little ice age occur (1550-1850)??

I am glad to hear you are skeptical of the computer models. So why are you worried? This only came into the common conscience when the most extreme simulation results were presented to the public. The range of other simulation solutions were not presented. The public is too stupid for error bars?

When the solution to the "problem" is raising taxes and world government you better make sure you are right.

The debate is not over as far as I am concerned. I do not know many people who believe this is a problem.


These are very sensible remarks. Ironically, everything would be much easier if oil hit $120 a barrell and stayed there. The there would be no economic advantage to not looking for or using other sources of energy. It seems clear that technology is the only thing that can really help with this situation in the long term but there is the question of whether it would be worth slowing down the warming to give us time to find the technological solutions (nucleus fusion or highly efficient solar combined with efficient storage in hydrogen perhaps?). In other words, is it worth sacrificing a percentage or two of global growth in order to buy us thirty years?


The trend among people who know what they are talking about is for the climate change sceptics to become less sceptical. It is always possible for people to present information in such a way as to create doubt in the mind of the layman. In cases such as these though, it is not worth pretending you understand the issues beyond your capacity. Ask super-smart people who spend their lives dealing with this stuff and if there is a broad consensus (which there is), that's your best bet.

He is worried about the models because while the models say that global
warming is going to be as expensive as the cold war (and considerably
more expensive than the war on terror) the models may be understating
the risk. Like, for instance, the models have been understating the
hurricane risk for the last few years. See the NYT graph for Tuesday,
May 23, citing the NOAA. Specifically, the models predict that
hurricane occurrences and intensity will go up slowly with global warming,
and they are going up more quickly than predicted. Ditto on glacial melt,
This may be because the modelers are terrified of crying wolf and would
much rather err on the side of risk and not have to worry about having
their funding cut off.
Me, I'll back the insurance companies against the coal companies. I
believe that global warming is going to happen, that it's too late to
do anything about it and too expensive to do anything about it, and we
should just accept that we are going to lose the beach houses and deltas
and like that.

"I do not much trust climate models": but then you can have no good reason to believe that global warming is caused by man. Inconsistency there, surely?

"I do not much trust climate models": but then you can have no good reason to believe that global warming is caused by man. Inconsistency there, surely?

No inconsistency is needed. Global warming has occurred (about 1 degree net in the last century, last I checked). Increasing levels of CO2 in the atmosphere will increase global temperatures. Human beings have increased the levels of CO2 in the atmosphere. We know that global warming has happened and we know that human beings have contributed to it, based on those three points, none of which are much dependant upon global climate modeling.

That does not get us far in debate, though, because the magnitude of effects is unclear: the models are not terribly trustworthy. Did humans contribute a little or a lot? What exactly are the harms involved and what are the costs of preventing/reducing/delaying them?

If, for example, global temperatures would continue to rise at 90% of the current rate if all human life just shut down, there is not a lot we can do absent extraordinary measures to lower global temperatures. If, for example, glaciers tend to melt more at the edges but bulk up in the center under current climate conditions, there may not be much in the way of sea level increases. Or all the worst-case scenarios could be understating things and we really really need to do something NOW because the effects will not fully kick in for 50 years.

If you believe that global warming from human-caused CO2 is a problem, it represents the greatest example of the tragedy of the commons. If we shut down all production as China and India kick into high gear, things are not going to get much cooler.

That is a lot of "if"s. And I certainly don't have the answers.

I read Kling's article about his distrust of climate models, and I wasn't impressed. Climate projections are guesses, true, but the physical realities that lie behind the models are very steady ground compared to the macroeconomic models Kling talked about. Climate models don't have to take into account people's beliefs about climate models, for one thing, and physical assumptions can be tested to a much higher degree of reliability than can assumptions about human behavior.

The projections are guesses, but they are conservative best guesses, and we should act accordingly. (It seems also to me that most of the projections assume unrealistic emission reductions).

Oh, and if you read (and if you don't read what the actual climate scientists blog about, what's your business posting on this topic? ;-) , the current article should be interesting to an economist, it's about voluntary emission compensation efforts - your home ground, not theirs.

Oh, and if posters like Rick did their homework, perhaps we could lay to rest the insinuations about the Medieval Warm Period, the little ice age and all the other noise being generated by political advertising agencies.

It's not clear whether Tyler is saying that he actually believes that global warming is significantly anthropogenic or if he simply thinks it's pointless to argue about it.

The only reason it isn't completely pointless to argue about is because the typical policy solution relies on the premise that warming is largely anthropogenic and that by changing human behavior global warming could be stopped. And I can't figure out why Tyler or anyone for that matter thinks global warming is significantly anthropogenic. Obviously more Co2 --> more warming, but magnitude matters. And so far when people talk about the significance of human warming, they seem to be talking more about statistical significance, like, yes we know it exists, versus significance in terms of magnitude or power (like would the instant end of all human activity do much to slow global warming?). It's hard to believe, but Tyler may have bought into an argument that anyone familiar with McCloskey should be very skeptical of.

"I recall reading that the Dutch spend about as a high a percentage of their gdp defending themselves from water as the U.S. does on national defense. That is quite a burden, but it is better than forsaking economic growth."

The combined ministery of Transportation and Water in the Netherlands has a budget for 2006 of 8,4 billion euro (10,70 billion dollars) out of a total federal budget of 146,7 billion euro (so roughly 5,7%). Less than half of that is spent on water management, so no more than 3% of the federal budget which is less than 1% of gdp
So in the current situation the Netherlands spents a far smaller percentage of gdp on water management than the US spents on national defense.
Nonetheless, in the past tremendous amounts of money have been spent on water management (f.e. the Deltaworks) and it is probably a smart idea for the US to reallocate some of its National Defense budget to Water Management. There is still one substantial difference between the two countries though; Half of the Netherlands is (already) below sea-level.

Well, I don't want to go into the science, since that is for climate scientists, geologists and such (although I don't trust the former anymore, too much denial and snobbism).

However, I think global warming is just a big excuse for getting a totalitarian state, or rather a facist state (if you look at Kyoto especially). Of course there will be a climate change and it will be partly man-made (or rather accelerated), but if I read the records of the 20th century correct, than we have an S-shaped curve that is going to signify a change.
However, I think the earth will adapt, which might or might not result in regional changes, perhaps it is even only intermediate and we will see a complete backlash after this peak...

The problem is that we have no solutions today. There is no possibility to substitute the automobile with something equally cheap as the Otto-Motor or the Diesel. There is no way to substitute nuclear power or coal power by more natural friendly sources.
Solar cells are by physical definition limited to a degree of efficiency of 15 %, not including losses due to heat, which would lower it. So, there is only reducing cost by optimizing manufacturing processes and minimizing costs of materials.
Water power is limited (as are Tide-power plants) to, well, water that stores potential energy (height difference).
Windpower is promising, since up to know only mediocre engineers have been planning windmills, it seems. There are many conceptional errors, which can be optimized according to my Professor of Product Creation and Analysis. However, windmills are a pollution to the environment and to inhabitants by itself and I don't think that they are the solution we looked for.

After all, the energy problem is not easily solved and so is the mobility problem, so there is nothing else to do as to adapt... or crash the industry and start all over again...

A. Request: Please write more on the issues in 6(a).

Two remarks re 6(a)
1. Shouldn't it be "economic growth per capita"?
2. I have been surprised how responsive population growth has been to economic success. i.e. how significant the birthrate declines have been in some countries as they become more industrialized.

B. I have become more "at ease" with this issue after studying
i. the 400,000 year temperature data from Vostok Ice Core and
ii. the similar history of ocean levels and
iii. ice age glacial coverage

Not that the implications are fun BUT that we can look back and see a likely range of temperatures, ocean levels and ice coverage.

In short - worst case the water levels will get no more than 20-30 feet higher (and could get 400 feet lower in a severe ice age).
So plot the limits of ice and water on a topographic map and you have your "Core Inhabitable Territory" (CIT). Plan accordingly.

The important point is that whether you believe or disbelieve global climate change based on anthropomorphic emissions, the climate history is strewn with lots of rapid significant changes, not to mention other global issues like supervolcanos and large meteor impacts.

Rich people can survive climate change better than poor people. This applies 50 years ago, today (look at Katrina), and 50 years from now. If we can move most of the Earth's population to being rich, we all will survive these climate threats much better than if most of the population remains poor.

We know the path to riches - economic freedom combined with strong & transparent institutions to uphold property rights.

I'm deleting Marginal Revolution from my bookmarks list. Mr. Cowen, you've become part of the idiot herd.

One thing that I can't figure out is how the skeptics seem to be continously waiting for some final, definitive piece of proof before taking action. As you say, it's ultimately a probablistic question and the concept of spending money to address the problem should be framed in such terms. Even if you don't care about Bangladesh, what's the total value of the global coastal real estate that would be inundatated by a 5 m sea level rise? Even if this is only a 1% probability occurrence, it's worth spending money to defend against. I've seen the same arguments sensibly deployed in favour of asteroid defense and they seem just as applicable here.

As for a plan? I'm not convinved it's as intractable or painful as people claim. First a few numbers for context:

- world GDP (according to CIA factobook): $60 trillion (PPP).
- cost of Iraq war to date: about $400 billion (born by one country!)
- annual extra cost to the world of $70 oil vs $30 oil (at 80 million barrels/day consumption): $1.2 trillion

These are some pretty staggering figures. Now let's assume that the world can afford 1% of GDP to fight global warming, that's $600 billion/year. So what do we do with out $600 billion/year? For simplicity's sake, we'll assume that the two primary sources of CO2 are coal/gas/oil fired electric power stations and vehicles so we'll only address these two. Global power generation capacity is about 4000 Gwatts, of which 60% comes from fossil fuels, or 2400 Gwatts. So here's the super simple plan. Replace it all with nukes. Assume that after a 5 year ramp up time of planning and construction, 400 Gwatts of new power (@ 1 billion/Gwatt) comes online (you had to spend $400 billion/year for the first 5 years to ramp up). It's take 6 more years to fully retire the fossil fuel plants but after 11 years, they're gone.

Now cars. the global fleet average needs to drop by, say, 30%. The solution (which leverages all those nukes we're building)...plug in hybrids. US fleet average is currently 27.5 mps for cars and 20 for light trucks. We'll assume that these numbers double with smaller fuel economy gains in other countries, where cars are already more fuel efficient.

Note that this hyper simplistic solution doesn't include more conservation, renewables (solar, wind, ethanol), carbon sequestration, etc. The point is that it's not as intractable as it seems. As to the means, I think all of here like market mechanisms but I suspect that they alone won't suffice. A revenue neutral gas tax in the US that sets a price floor @ $4.00 a gallon would be a good start. I imagine that there are many other good and imaginative (and non-totalitarian) options.


You wrote: "Even if this is only a 1% probability occurrence, it's worth spending money to defend against."

The amount that is sensible to spend NOW depends upon not only the probability of occurence, but also the expected timing of the rising-sea occurence you hypothesize. If the expected timing is a hundred years from now and the probability of its occurrence is the 1% you suggest, it will be sensible to spend almost no money NOW.

The asteroid story that you think is identical is probably different because the timing of an asteroid strike is less subject to forecasting.

Eli -- just to pick one example, pretty much nobody outside of a cover in Newsweek were seriously worried about global cooling. And the idea of randomly assigning 50% Bayesian probabilities to everything is just silly.

As for the rest, check out here. There's a lot of misinformation here. Realclimate is also invaluable.

a few comments:

Sandy P: I never said who would spend the $600 billion/year. I just threw out that figure as an approximate cost. In practice, I there would be two key mechanisms (i) each country would commit to CO2 emission reductions and implement whatever mechanism they chose to achieve it (e.g. carbon taxes, nuke subsidies, etc.) (ii) there would be some mechanism for wealthier countries to subsidise the large but still relatively poor countries with high CO2 emissions (which really amounts to India and China). This could potentially be done in a pseodo-bilateral manner (e.g. negotiations between the OECD and India and China directly) that entirely bypasses the UN, if that's the concern.

jim: as you said, it's more complicated. There's the question of the expected cost of greenhouse effect induced damage and associated timeline. In addition, there's a continuum of potential outcome: the median predictions with their cost, the 90th percentile, 99th percentile etc. But the timeline uncertainty must be weighed against the fact that any solution will take a long time to take effect due to the long lead times in mitigation projects (like building nukes) and inertia in the global climatic system.

The thing that I keep coming back to is that the kinds of things that we need to do are not civilization enders. We're not even talking about causing an global depression. I find it very hard to believe that there's so much resistance to such relatively small pain (i.e. the 1% of GDP figure) given the potential risks involved.

China can afford it if they stop beefing up their military.

A new paper was just published that shows a 95% probability that forcing from 2x CO2 levels will be under 4.5C, and realistically will be around 3C. At this level of forcing, I'm very confident that new technology will solve the problem.

Solar, batteries, fuel cells are all seeing exponential improvements in price/performance, and nuclear pebbles is a promising new technology on the nuclear side. I think we have plenty of time for these to come to fruition and replace existing CO2 emitting techologies on a cost basis.

The paper is in GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L06704, doi:10.1029/2005GL025259, 2006 with a free draft at draft.

The author's blog explains the reasoning behind the paper: Climate sensitivity is 3C. As they say: We have explained in very simple terms why the more alarming estimates are not valid, and anyone who wants to hang on to those high values is going to have to come up with some very good reasons as to why our argument is invalid, coupled with solid arguments for their alternative view.

Two ideas stand out in comments. If the other planets are heating up also, the driver is solar output. The L2 reflector idea might run into solar wind constraints, although admittedly the self-correcting factor of using libration points is a good one : what about the angle ?
But stratospheric filtering ( a sunbrella ) would be a possible controllable idea.

finnsense says:

Ask super-smart people who spend their lives dealing with this stuff and if there is a broad consensus (which there is), that's your best bet.

And what is the proof that "super-smart people" (however selected) are most likely correct? Last time I checked all indications were that scientific studies and experts were later proven wrong 50% of the time. E.g., for years people ceased eating eggs because scientific experts said eggs would raise their cholesterol; more recent studies found that 2 eggs a day is OK for most people. With experts like these, I'll trust to the fools.

When Woody Allen wakes up in the distant future in his 1973 film, "Sleeper," he finds that steaks, cream pies and hot fudge sundaes are now considered health foods. I expect as much of science these days.


I'm all for sensible doubt but if I have a choice between believing my intuitions and some repeatedly empirically tested science, performed by people whose integrity I have no reason to doubt, I'll go with the science. Scientists get things wrong but they also get things very right a lot of the time. Usually where they get things wrong it's because of a lack of rigour in testing the claims. Climate change has been tested over and over again by people all over the world and the evidence for it has become stronger not weaker. The only reason you might have for doubting it now is because you are a massive conspiracy theorist or because you don't want to believe it.

I'm still puzzled by this idea (in item 4) of placing no trust in climate models and then agonizing over their large variances and worst-case scenarios, of their uncertainty supposedly giving us "more to worry about". Large variances are a sign of inadequate data and/or models; horrible worst-case scenarios are little more than an artifact of the large variances. Neither is (or, should be) a special cause for concern, especially if (as you claim) you doubt the model in the first place.

Suppose I whip up a computer model designed to gauge the probability and likely effect of an alien attack. Needless to say, to get anywhere I will have to make many assumptions, inferences, wild-ass guesses, etc., etc., etc..... The output of the model will certainly have large variances. And, the worst-case scenario of the model will be horrendous (just let your imagination run wild). Can I assume that because of the uncertainty, Mr. Cowen will conclude that my model gives him "more to worry about, not less"? ;-)


You say, "people whose integrity I have no reason to doubt". People on both sides of the debate are making a living from it. How many climatologists were tenured 20 years ago? How many are tenured now? How likely is it that they could continue to get research funded if no one cared about global warming? How many of today's climatologists would have been physicists or chemists or geologists if they were just a bit smarter? How many questions the answers to which I don't know can I ask? b^) But you get the point...

I will never be convinced by an argument from authority. If we are speaking seriously about economic regulation on the scale mentioned elsewhere on this thread, it is irresponsible to abdicate all decisions of fact to official "scientists". All thinking people are capable of downloading relevant papers and locating the actual hypotheses considered and experimental techniques employed, even if not everyone can critique the physics, chemistry, and statistics.

I have done so, and my conclusions are these: in recent times, which humanity has directly measured, the temperature has gone up. Before that, we're not so sure what happened, but it seems that the temperature went up and down. The global climate is a complex phenomenon with many drivers, some of which we measure. The carbon content of the atmosphere is certainly one of those drivers, as is solar output. We can be sure that human contribution to the former is strictly between 0% and 100%, and that human contribution to the latter is 0%. Both of these two quantities have increased recently. Beyond this nothing has been shown without the aid of uncontrolled computer modelling, that is, without the employ of unscientific techniques.

Without the scientific method, we are left with natural philosophy. Philosophy is a noble pursuit, but it should know its place. Maybe it's because I've read too much history, but I'm skeptical when a philosophical theory requires the entire world (or more commonly, large Eurasian nations) to drastically alter freely-chosen lifestyles. Such episodes have offered many opportunities for rent-seeking.

Wow. I must confess that the amount of misinformation and disinformation about GW from the "skeptics" in this thread is simply staggering. No, we're not in a 7-year cooling; the warming is accelerating. No, the atmospheric warming isn't saturated with C02; if earth had the C02 concentration of Venus, the earth's temperature would be far above the boiling point of water.

You don't see how a sea rise of 30 feet, desertification of the mid-continental regions, climate changing faster than plants can adapt, and propagation of tropical diseases to temperate regions could be bad for humans? You don't see why scientists in a field know about the field than a layman does?

Global warming is a fact. It is observed and measurable. Its early effects, such as reduction of ice in the Arctic and the spread of tropical diseases to temperate regions is well documented.

That C02 is a greenhouse gas is fact. That C02 concentrations are rising is a fact. That humans produce large amounts of C02 is a fact. That part of the warming is caused by humans is a fact.

About the only thing not cerain is how much of the warming is anthropogenic -- 30%, 90%, >100%? We don't, in fact, have any independent evidence to assume that the earth would be warming without anthropogenic forcings. The Little Ice Age that skeptics are so fond of dusting off was actually a series of temperature minima, the last of which ended around 1850. Who ever said that was the last minimum? We would be due just about now to be in another minimum. No one can say the earth isn't in a cooling trend right now that is being completely obliterated by anthropogenic warming.

If anything, the observations from the past few years indicate that global warming is worse than most serious scientists thought, and that the warming is accelerating. Scientists regularly pull in the dates by which the Arctic oceans will be ice free, from 2100 to 2030, and now there is even a hint that it may happen by 2015.

There was a time back in the 90s in which it was possible to argue that the science wasn't understood well enough, that doom and gloom predictions are usually wrong, etc. When someone predicts a flood, it is time to stop questioning the prediction once the water is swirling around your ankles.

A group of researchers recently sampled 10,000 papers on climate change published in major journals like Science and Nature. Out of 1,000 papers randomly selected, they found zero that contradicted anthropogenic GW. That's right, none, nada, zilch, zip. Yet during that same period, 52% of the papers cited in the media contradicted anthropogenic GW (the 2% was probably because of Fox New...the rest were just trying to be "balanced".). Is it any wonder people are misinformed?

Check out the various links cited by other folks in this thread, especially RealClimate.

The following is meant to be legitimate question not fun-poking.

Why does the melting of the ice around the world mean that water levels will rise? If I fill a glass half full with water and then add a few ice cubes, the water level will rise in order to compensate for the new mass added. If I let the ice melt the water level will stay the same. The level does not change because the mass in the water has only changed forms. Are the poles actually land and not floating pieces of ice?


Interesting, but contested. Nuclear power is under the suspicion of creating greenhouse gases, because it is creating water vapor amongst other things. Greenpeace and other environmental groups have long been pondering this point and there are several scientists amongst their affiliations who back up that this is a null-sum game with nuclear power.

First I am studying mechanical engineering, so economics is as foreign as climate science. The difference between climate science and economics is that the latter is not sure whether there equations produce a solution all the time, while the first assumes it. However, good economists grant that power should rely with the individuals making choices and not with an entity commanding around. And here we got the problem I see. I am all for individual choice to save the planet, because then the cost would be on the wealthy people and not the poor or those who don't consider it that important a problem.


I don't listen to Realclimate, because it is censoring posts (not only the rants, but also inquisitive posts). The question is why a state-funded climate scientists is more trustable (because his money is bundled to the necessity of his position, which guarantees alarmism) than commentators (with technical degrees) funded by private means? It is not the funding but the arguments that should be worked on!!!

I am also all for cross-examination between scientific fields, because they bring new insights with it. Sadly, climate scientists believe themselves to be an elite elected group of people with special privileges. How else can you explain that they don't even want to share their source codes and obtained data (while geologists are sharing all the time Oo). I do not comment on the actual science, like temperature tables and such, because there are so many mixed arguments out there and no real answers to either sceptics or pro-climate-change (as explained I regard global warming to be a straw-man, but climate change to be very real). I don't trust computer models (hell, I don't trust FEAs right off and those are easy computer models Oo) and much less projections based on guessing. However, I respect detailed facts on the past and they show an increase in warming (faster than before?!) and we have to see what comes from it.

Patinator: you're right that Arctic sea ice melting shouldn't affect sea levels (though it'd dramatically change the local climate, and maybe change the Atlantic currents, giving Europe a climate more in keeping with its latitude.) But the Greenland and Antarctic (not to mention glaciers elsewhere) ice sheets are on land (mostly, for Antarctica), and if they melt their water will be added to the ocean. (And, incidentally, we'd lose the scientific atmosphere data trapped in their layers; I don't know that they've been completely cored yet.) At 14 million km2, and an aveage of 2.5 km of ice, and ocean area of about 3e8 km2, all that melting could easily raise levels by tens of meters.

Re: Point 6

Check out the work by Roger Pielke Jr. at Colorado (and his excellent blog, Prometheus, for alternatives.

This article is a good start:

Tyler Cowen,

How do you square your belief in global warming with your pro-immigration views? If global warming is real and we need to cut our consumption of hydrocarbon fuels to deal with it, is this not likely to reduce economic growth for existing U.S. citizens? In which case, why do you think that adding lots of new immigrants to our country is going to help us reduce greenhouse gas emissions?

Given that people like Hansen claim that particulates are a huge factor in changing albedo, the obvious policies to explore are ones placing more particulates of the right kind in the right places. Or we could put more sulfur into our jet fuel to create more reflecting clouds. Solutions of this sort are almost certainly orders of magnitude of cheaper than trying to manage energy consumption with public policy.

> almost certainly cheaper

What's the cost of putting sulfur into the fuel, and of cleaning up the acid rain afterwards, and what's the effectiveness of doing so? What are the costs of putting Pinatubo-levels of particulates in the air? What is the cost of energy use reduction, or energy use shifting to non-fossil fuels?

> promote economic growth

Growth 100 years from not doesn't help people who are hurt today. And mitigating climate disruption might *be* the most effective way of ensuring economic growth.

Nuclear power should definitely be promoted. There is a new kind of reactor, called the integral or advanced fast reactor, that eliminates all of the problems (like nuclear waste, power plant lifetime, etc.) that plague current nuclear power plants. The IFR (or AFR) would be 100 times more fuel efficient than current nuclear power plants. The fuel recycling is done in the same building as the reactor. Yucca Valley would be unnecessary as the waste that is supposed to go in it would actually be fuel for IFR plants.

Toshiba recently bought Westinghouse for around $5 billion. They definitely know which way the winds are blowing.

There are two ways to remediate greenhouse gases that would cost very little and be easy to implement. One is to dump irom power into the oceans to boost algae growth. The resultant growths of these algae will consume the excess CO2 in the air. The second is to add particulates to jet fuel (not sulfur but something non-toxic) in order to increase the earth's reflectance of sunlight. The choice of particulates should be optimized to screen out IR (700-2500nm) rather than visible light (380nm-700nm). If we can screen out UV, that would be added bonus.

Another very logical approach to reducing greenhouse gases, as well as hydrocarbon use, is to simply offer a series of X-prizes for the development of commercial fusion power. These prizes are being offered for space and anti-aging. Why not offer them for developing fusion power?

All of these approaches are far more sensible, not to mention pro-technology and pro-growth, than trying to regulate emissions. Greenhouse warming being real or not, the regulatory approach is a dead horse. Get over it and move on.

Nuclear power is under the suspicion of creating greenhouse gases, because it is creating water vapor amongst other things.

Who said that? It's an idea that displays an ignorance of how the climate operates. Water vapor levels in the atmosphere are controlled by evaporation driven by the 100,000 terawatts of solar energy that hits the earth (most hitting the oceans), not by the terawatt or so of waste heat dissipated by the world's nuclear reactors.

(A related fallacy is that fossil fuel combustion significantly affects atmospheric H2O via the water produced in combustion.)


The economic law of demand and the law of diminishing marginal returns are as solid today as when they were first conceived (at the birth of the field). It is unfortunate that you are willing to criticize the bedrock of economics without knowing what it is. But you shouldn't allow yourself to feel too badly about this because there are many also do not know this (and some who do not know this have the gaul to call themselves economists).

To answer a question above - the rising of global sea level has been the result of thermal expansion of the ocean (not ice cubes melting in water). If, however, the West-Antarctic Ice Sheet were to fall into the ocean (one of those low-probability, high-consequence events Tyler rightly rears) then the resulting sea level increase would derive from dropping extra ice cubes into the glass.

Max:"However, I think global warming is just a big excuse for getting a totalitarian state, or rather a facist state (if you look at Kyoto especially)." That is what we call a conspiracy theory, and I wonder where you got your data on Kyoto. Dan Brown? Nah, probably Michael Chrichton...

Jim: "It is my understanding that the last 7 years we have been on a cooling trend." Where on earth did you get that "understanding" from? Come on, it's not so hard to come across graphs showing the instrumental record. I don't see any downward trend there, particularly not in the last seven years. And anyway, to do the same we did these seven years - have you heard of something called latency? You don't push around immense things like the climate quickly.

scm: "And I can't figure out why Tyler or anyone for that matter thinks global warming is significantly anthropogenic." Well, if I were you I'd take some time to find out, because it is the scientific consensus, you know? stands as the suggestion. Those people have publication records as long as a bad winter, and they do answer both stupid and deep questions.

Eli: "Remember that in the 1970s everyone was fussing about global cooling." Some newspapers were. Natural scientists as a group certainly weren't. What tabloids did in the seventies (worry about "nuclear winter") is an extremely bad reason to disregard today's expert opinion.

Mace: "Another problem with global warming: the Leftist-enviromentalist proposed solutions don't involve markets, just more government and less freedom."
Kyoto is a market-based solution (or rather, a step towards one). And you know, cap and trade has been very successful in other areas. Are these ideas leftist-environmentalist? Most policy proposals from environmentalists (as opposed to suggestions of what you can do yourself) are market based, as far as I can tell.

Keith:"I'm deleting Marginal Revolution from my bookmarks list. Mr. Cowen, you've become part of the idiot herd."
Well, to you Cowen (as Keith won't be reading this), you still have the arrogance and camaraderie of your profession, which apparently makes you value Kling's opinions on climate models more than the climate scientists'. But that does not quite make you part of an "idiot herd" of economists, in my opinion. If I can put up with Kling (I read econlog too), I can certainly put up with you.

Oh I'm getting tired of this. One last one :
Jeffrey Smith:"Who pays for the production of an argument, and the ideological bent of its producer, is irrelevant to its evaluation. Many climatologists sort into that field because of their ideoglogical beliefs." There's a difference between having a vested interest and being an advocate. Coby Beck has a good article on the difference, and on this part of the climate debate in general.

But I would like to point out that funding does matter.

Knowing that a person has an economic interest in promoting a certain view may reduce the value of his statements, because we require more independent verification before we can trust them. That is why many scientific journals demand that contributors notify of any conflicts of interest they may have. Note that we say conflict of interest, because we assume that in addition to his interest in a certain view winning approval, the scientist has a sometimes conflicting interest in finding out the truth.
But in other areas we have seen paid advocates deliberately spreading information they know to be false. These people don't seem to have a conflict of interest, because they just have an interest in promoting a certain view, at all costs. When asked directly how much it would cost to get him to promote Linux instead of smearing it, Ken Brown of the Alexis de Toqueville Institute answered "we can talk about that". There are some people like him, who believe that ideas deserve all the protection they can buy, like the accused in a court. They see themselves as a sort of lawyers for ideas.

(They are wrong, though. Different rules apply for ideas. They don't deserve an assumption of innocence, for one thing!)

These people spread noise. They are paid to ignore criticism, make headlines, give an impression of controversy where none exists. Since honest people have a limited amount of time and resources to answer their campaigns, assigning less weight to their opinions is legitimate and reasonable. So is ignoring them. We do that to blog trolls, and it applies here as well.

My time in answering the most obvious misinformation is short, and it will soon be up. I hope everyone takes care to be critical of people with a conflict of interest, and be most skeptical of paid advocates like the CEI. Paid advocates on both left and right often strive to associate themselves with ideas or people their target audience likes ("Competitive enterprise" and Alexis de T, I am sure people here can think of the left equivalients).

I ask you all: Don't be fooled by that. Don't uncritically accept the opinions of people who say they agree with you, especially when they go counter to practically all experts in the relevant fields.


I read it in my Sunday newspaper. In Indianapolis, we don't just get left wing clap trap on our editorial page.

Er, 'scatterers'.

Jeffery Smith:
"Policy can compensate for either man-made or nature-made warming."

The most ignorant coment I have ever seen on this blog. Geological power is one of the most awsome and destructive forces on our planet ... and you think some monkeys in suits taht make policy can "control" it? I certainly hope you don't mean that.

It's kinda like trying to control a bull while bull-riding, you don't control, you hang on for the ride and pray you don't get kicked in the head.


I read it in my Sunday newspaper. In Indianapolis, we don't just get left wing clap trap on our editorial page."

So you are saying you also get empirically false information? How's that working out for you? (kinda rhetorical, you probably shouldn't answer)

Being rather new to this blog, I'm not sure what it says about those who frequent it that out of (at this point) 80 comments, not one has yet mentioned the work of the Rocky Mountain Institute, which, as an organization dedicated to profit-oriented market-based solutions for energy and resource related problems, would seem a natural fit for those with a libertarian economic bent.

So, with regard to Tyler's items #5 and #6, everyone should immediately go view this talk by Amory Lovins, given at the MIT School of Engineering last February, on Winning the Oil Endgame.

Tyler, I really hope this comment catches your eye, because I'd dearly like to see a future post on what you think of his assessment of the opportunities inherent in our current situation. I can't do justice to the wealth of knowledge and experience Lovins brings to the question of how and why our economy is already moving to completely eliminate oil as an energy source over the next few decades, but the essence of his argument is this.

First, given the capabilities of currently available technology, and of new technology currently coming online, our economy is highly wasteful in its use of oil, natural gas, and other fossil fuels (i.e., precisely the fuels which release greenhouse gasses as a byproduct of their use). In fact, we are so wasteful, that therein lies a tremendous opportunity. These are technologies which are manifestly superior for providing the end-use services we actually care about. They are not the sort of conservation measures that require us to "turn down the thermostats and shiver in the dark in winter" to save fuel.

Second, the economics of these technologies is such that it is radically less expensive to "mine" the economy for increased efficiency to save a given quantity of oil, than it is to buy that same quantity of oil or develop new sources for it, much less expand the use of costly technologies like nuclear which would utterly fail in the marketplace were it not for subsidies. For this reason, any money spent expanding nuclear generating capacity or drilling in ANWAR is wasted. A far greater return on investment is available by adopting technologies which provide higher quality end-use services and yet do so more efficiently than our current capital stock.

Third, the implementation of these technologies is already underway, led by those private, for-profit businesses which see what's happening and understand that the greatest profits will be reaped by those who are out front in adopting technology to reduce or eliminate dependence on oil. To the extent there is a role for the public sector in this, it lies most importantly in eliminating the perverse incentives of existing policies which actively interfere with this transition. Lovins does identify a number of short-term policies to create incentives which are aligned with the market forces driving increased efficiency, rather than opposed to them, but he makes it clear that they are not essential. The transition will happen anyway, and their sole purpose would be to reduce the time we take reaching the critical mass necessary for the transition to accelerate exponentially and irreversibly.

Finally, as far as this transition off fossil fuels is concerned, the question of human-induced climate change is irrelevant. The economics of getting off oil and other fossil fuels is utterly compelling even if the global effects of our massive, uncontrolled, and reckless experimentation on the atmosphere is not taken into account.

Now having said all that, with regard to Tyler's item #4, there are definitely problems with the integrated assessment models of climate change used by economists who work on things like the Kyoto treaty. These are computer models of the physics of the global climate system which have been coupled with models of national or global economies, for the purpose of exploring the economic costs and benefits of alternative policies for mitigating human-induced climate change. However, the problems are found in the general equilibrium economic models being used, not in the climate system models, which are by now firmly grounded in the fundamental principles of chemistry and physics which drive the behavior of the atmosphere and oceans. For more on this, especially for those of us with a background in economics, I recommend the brief but excellent Economic Models of Climate Change: A Critique by Stephen DeCanio of UC Santa Barbara.

And for those genuinely interested in developing an informed layperson's understanding of climate science, I suggest starting with Climate Change: The Discovery of Global Warming, which offers a detailed history of how the science of climate was developed during the past century, and then continuing (as noted by another poster above) with RealClimate, a blog by working climate scientists, established to counter the extensive amount of misinformation, misrepresentation, and outright lies on this subject which circulate in the media and in our political discourse.

It's an unfortunate characteristic of our times that we are plagued by an attack on climate science coming precisely from that segment of the political spectrum which, on a wide variety of fronts, is now in open war with Reality (and, as noted by Fafblog, with Reality's "advance guard, Information"). But given that this propaganda war also includes a sustained attack on the reality of evolution as the means by which Nature generates new species (the science of which is every bit as firmly established as that of the helio-centric solar system), the ignorant opinions of those who deride as "junk" the results of a century's worth of research in climate science by people who actually know what they're talking about, isn't worth a puddle of warm spit.

Fortunately for us all, Mr. Lovins demonstrates masterfully that the fate of our civilization, which does indeed hang in the balance, is not in their hands.

"Geological power is one of the most awsome and destructive forces on our planet ... and you think some monkeys in suits taht make policy can "control" it?"

Hey, God told us to have dominion over the earth, right?

More seriously, I think geological power might be overrated. It's awesome when it goes off but it takes a long time to build up to that. The total heat flux from the core is on the order of our total energy use; I forget which is bigger right now but they're within a factor of 2. 10 billion people at US energy levels would use more energy. My crude estimates for the power behind a volcano or earthquake have ranged from megawatts to about a gigawatt, i.e. that of a power station. I don't have any bright ideas for controlling earthquakes, but it seems like volcanism could be controllable by drilling down to magma pools and tapping the geothermal energy, while letting off the CO2 in a controlled and perhaps sequesterable fashion.

Sample calculation: 1 cubic kilometer of rock blasted 10 kilometers high is 3e12 kg * 1e4 meters * 10 m/s2 = 3e17 J, about a day's worth of US energy use. If it happens once a century (3e9 seconds) at that volcano then the average power would be 1e8 Watts.

Sample check of calculation: 1 cubic kilometer of molten rock contains 3e12 kg * 3000 K * 1kJ/kgK = 9e18 J. Bigger, and representing 3 gigawatts; still on the scale of energies we manipulate in our plants.

Taming geology may be undeveloped technology but as a magnitude it's right up our alley. Hurricanes, now, those are awesome, but they're backed by the sun, not the trickle of heat from the core.

The idea that global warming leads to more violent storms is silly. It's the _difference_ between temperatures of mid-lattitude and equitorial oceans that drives the energy of hurricanes, and there's no good evidence that global warming has or will increase this overall difference. Indeed, Jupiter and Saturn are freezing yet have quite violent storms, and cool Earth's storms are generally more violent than hot Venus' storms.

There may be certain local and temporary increases and decreases in the difference, from a variety of causes including global warming related events, but no good evidence to believe this will sharply depart from the purely natural pattern of variation.

I didn't mention hurricanes to blame global warming for them; I was just saying I think they involve more energy than vulcanism.

I remember estimating that the big quake in Indonesia also had a gigawatt behind it, but that's dependent on various assumptions I had to make up. I'm more confident of my Yellowstone caldera analysis; the thing can coat half the US in 1.5 feet of ash, about every 650,000 years. Say it coats the whole US (1e13 m2) in a meter of rock (1e13 m3, 3e16 kg), lifted again to 10 km: 3e21 J. Say it's every 300,000 years, 1e13 seconds: 3e8 watts.

As a heat reservoir, that much molten rock would be 3e16*3000*1000 = 9e22 J; the US uses 3e12 watts, so at 33% conversion efficiency tapping the reservoir might power the whole US for 300 years. Not bad.

Ronald: looking at that pdf again, I don't see any tables at all. This was UCRL-JC-148012, right? In any case, the earlier link I gave doesn't seem to claim anywhere that a space shield would have a mass of a million tons.

To answer your other questions: the solar wind actually has a very low pressure compared to the pressure of sunlight itself; 'solar sailing' is done using photon pressure. The small-angle scattering shield would experience much less force from light pressure, since the photon momentum change is much less. The end result is that acceleration from light pressure stays the same as scattering angle decreases, since the mass and force scale similarly.

There would be some force, so the shield would be placed somewhat inward from the L1 point so solar gravity would compensate. The equilibrium is unstable, so there would have to be active feedback to keep it in place. This could be provided with small movable completely reflective segments (total area much less than the overall shield). These would also provide attitude control, and could be used to move the shield(s) into position. I believe they estimate the 'dressed' mass of the system would be about 10,000 tons.

As for 'less than thousandth of a micron thick': the shield will of course not be a uniform sheet, but rather be mostly empty space, with a network of structural elements supporting an array of scatterers, probably as a mesh. Similar ideas have been proposed for high performance solar sails, where you can perforate the sail with holes < 1 wavelength in size and it remains mostly reflective. The biggest problem, I think, would be manufacturing this shield, with its intricate structure at the micron scale.

I've seen lots of questions being addressed on RealClimate. And I'm afraid their being "notorious for" in certain circles doesn't constitute strong evidence for me. The warming sceptics are "notorious for" astroturfing up opposition.

"...without continued economic growth the world will probably fall apart..."

Dude, economic growth is what's got us into this mess in the first place. Advocating more as a solution to our problems will only make matters worse, and ensure that the world will fall apart as a result. Have you considered the implications of exponential growth in the real world? Algal blooms, stock market bubbles? Such manifestations of exuberance are all ultimately unsustainable. To think that our economic system is somehow exempt from physical laws and will, or can, keep growing in perpetuity, is simply wishful thinking. Man-made global warming, general resource depletion, accelerating species extinction, biosphere destruction, all are signs of the stress our growth mania is having on the earth - no matter how hard we try to kid ourselves otherwise. Whether we like it or not, growth on a finite world has got to come to an end, sooner or later. Either we choose to end it now, as humanely as possible, or nature shall eventually impose it on us willy-nilly. The problem is, with everyone encouraged to do their own thing, who amongst us will be first to voluntarily leave the party?



What is the standard error of the estimated one degree increase in the 'global' temperature over the last 100 years, and how exactly do you measure the global temperature? I'm assuming it is some sort of a weighted average of temperatures across the surface of the earth? How many data points are used? I imagine that 100 years ago it would have been relatively more difficult to measure than it is today. I suspect that through the use of satellites we are able to measure surface temperatures for virtually every square meter or so of the earth, but 100 years ago how was this done and what does that imply for the accuracy of the measurements 100 years ago?

Not to sound thick or anything, but if the U.S. and other fully developed economies chose to invest heavily in CO2 reduction then I'd have thought economies of scale would reduce the cost of new technologies to a level such that China and India could afford to employ it. Especially if a lot of the engineering and/or manufacturing was sub-contracted to firms in those countries.

I don't have time to google up references, but I'll try to prime your intuition: you can't eat knowledge, but you can use it to do things more efficiently. A Franklin stove heats you more efficiently than a chimney which in turn beats an opean hearth. A power plant with co-generation does more than the same power plant which just dumped its heat to the environment, without using more energy. Using better insulation in a home keeps you warm for less energy than before. Carbon fiber polymers weigh less than steel, and we're using them more and more -- not that there are many substances we're likely to run out of, copper and platinum group metals being the closest candidates. Atoms are cheap, energy's the main concern. Desalination via reverse osmosis uses maybe 1000x less energy than doing it via evaporation without heat recovery. A lightweight car uses less gasoline than a bigger one, and if made out of advanced materials needn't be smaller or weaker. Fuel cells can be more efficient than combustion engines, though we don't seem to have the whole cycle worked out yet. Hybrids are more efficient than regular engines. There are lots of ways in which more knowledge lets you do more for less.

And saying oil is more calorific and fungible than electricity seems incoherent to me. We use fossil fuels to make electricity, which is extremely fungible, though not so good for running cars or planes. How do you measure the calorificness of electricity, anyway?

There are limits to efficiency-fueled growth but we're not near a lot of them.

From what I can gather,

1. Most climate scientists say that warming is real (1 degree C the last century), and will probably continue (2-4 degrees C the next century).

2. Most economists says the costs of this will almost certainly exceed the benefits (for humans). We have a tremendous "installed base"--like farms and coastal cities--that would have to change. They also say that the costs of the Kyoto treaty would substantially exceed the benefits.

So let's drop Kyoto and instead talk seriously about developing laws and technologies whose benefits will exceed their costs.

More efficient cars, fridges, A/C, lighting... they say 3/4 of gains are real, vs. structural or fuel switching."
You're being disingenuous. I said a significant proportion of these changes (energy efficiency/intensification) were attributable to a switch in fuel types AFTER WWII, the ACEEE only talks about post 1973. You could safely argue that the great expansion of the world economy after WWII could not have occurred on the scale that it did if it was not for the explosive growth in transportation - particularly private land-based transportation, all fueled by the plentiful availability of cheaply produced regular oil. After 1973 the US was no longer world oil swing producer having peaked in c.1970. The oil crises of the 70's with a more than ten-fold rise in the cost of a barrel of crude was largely a result of US inability to regulate the price of oil anymore by simply turning on the spigots, producing more oil, and therefore lowering the price. OPEC must have known this fact which is why its embargo had such a dramatic effect on the American and world economy. The subsequent contraction in supply forced a shift towards conservation and efficiency in many ways. For instance the US moved to increase the level of natural gas –fired electricity generation because the cost of energy (i.e. petroleum) needed to produce it was much lower.



Found a reference for worldwide energy use/GDP. Note the 13% decrease between 1990 and 1999. Note that the world as a whole can't export its energy use.

"Greenland may become valuable"

I don't think so, unless supplying a large dollop of fresh water to the North Atlantic is considered valuable. (Two effects would result: sea level rise, and slowing down of North Atlantic drift due to freshening of surface waters preventing deep water mixing, cooling off Europe's climate).

Climate change is real, and the anthropogenic effects are significant. The CO2 levels in the atmosphere are above levels seen in the last 650000 years. They cannot be explained in the context of Milankovich cycles. As such, we are forcing a non-linear system into a regime without historical precedent (during the time-frame for which we have data). Economists are used to the dramatic shifts that can occur in non-linear systems (market crashes are one example).

I see that, finally, many economists are acknowledging global warming. The majority still advocate only doing anything it if economic growth is not threatened.

Such economists need to befriend a climate scientist and go through the data. In particular, look at the CO2 ice core records. Then think about how you'd feel if you were in a country going into a regime with, say, unprecedented trade and budget deficits. How comfortable would you feel about economic prospects. Then transfer those feelings to the ocean-climate equilibrium that supports all life on Earth.

And can the world cooperate on such large projects as reducing greenhouse gas admissions. Yes, I think they can. It takes leadership and communication, but it can be done. (Although the Bush, Blair, Harper and Howard leaders of the English-speaking free world certainly aren't going to help.)

"Found a reference for worldwide energy use/GDP. Note the 13% decrease between 1990 and 1999. Note that the world as a whole can't export its energy use."

This just shows that the level of energy consumed per unit of income. The price of oil was severely depressed during most of the 1990's so it makes sense that you could buy more of it per unit of currency. What you neglect to mention is that on the chart marked "Energy Consumption by Source US 1971-1999" the level of energy consumption in general, and of fossil fuels in particular rose steadily in that country during this time.



It seems blatantly, pathetically obvious to me that the correct way to regard India and China's ongoing modernization is to say, "Cool! We have vast potential markets for the new clean-energy tech we're going to build. Let's pump billions of dollars into research, as fast as they can be effectively absorbed, and get on top of this issue before the Japanese, Koreans, and Europeans, not to mention the South Africans, Australian, Indians, and Chinese, fill up the market and make it a low-profit area."

"Well, if you do not trust computer model just look at the 'stars'.

Venus for example, the "gold star" in Japanese. 96% of carbon dioxid. Huge greenhouse (and pressure) effect. 400°C-500°C."

And then look at Mars...or Red Planet, in American:

Atmsospheric composition?--->95% CO2.

"Carbon dioxide (95.32%), nitrogen (2.7%), argon (1.6%), oxygen (0.13%), carbon monoixde (0.07%)

"To think that our economic system is somehow exempt from physical laws and will, or can, keep growing in perpetuity, is simply wishful thinking."

I predict the following world average per-capita GDPs (in year 2000 dollars...based on $7,200 in 2000):

2020: $13,000
2040: $31,000
2060: $100,000
2080: $1,000,000
2100: $10,000,000

Those predictions are based on historical technology and economic trends, projected into the future.

What are your predictions? And what are your predictions based on?

A lot of people believe that global warming does not exist simply because the planet gradually gets warmer and cooler with time, but the fact lies within the word "gradually." Gradually, not quickly. The rising and falling of earthly temperatures takes millions of years. An advancement in temperature of one degree celsius, in the past, took a thousand years. Since the 1950s, the temperature has risen several degrees. That's only fifty years, if my mathmatical skills are functioning properly.

We need to do something about global warming.Some people don't think it is an issue but it is. It is realy causing alot of problems and instead of just thinking about what it is doing we need to actually so something.


Please read my report my space "global warming:the only solution" with additional links regards John

nothing we can do about global warming , in the last 70 years the earth has gotten 1,000,000 miles closer to the sun, thats why we are looking so closely at mars, so we can go there when the earth gets to hot, think about it, the sun is 93,000,000 miles from earth , and we can still see it, thats big, the gravational pull , is slowly pulls all the plantes , earth was at the perfect spot for life, next mars will be there, , mars is to cold now , and veneas(spelling) is too hot ,it is so simple, nobody says anything because they dont want the public to freak out , but thats what i feel is going to happen, when earth gets to hot we will be sending people to mars, thats why we spend so much time looking at mars, and not the other plantes closer to the sun, we forget about mercury, and venes,(pls excuse my spelling )thank you , it is just my thought

Comments for this post are closed