Freeman Dyson reviews A Question of Balance: Weighing the Options on Global Warming Policies by William Nordhaus, and Global Warming: Looking Beyond Kyoto edited by Ernesto Zedillo, and finds them strangely silent on some important issues.

There is a famous graph showing the fraction of carbon dioxide in the atmosphere as it varies month by month and year by year (see the graph on page 44). It gives us our firmest and most accurate evidence of effects of human activities on our global environment. The graph is generally known as the Keeling graph because it summarizes the lifework of Charles David Keeling, a professor at the Scripps Institution of Oceanography in La Jolla, California. . .

The graph has two obvious and conspicuous features. First, a steady increase of carbon dioxide with time, beginning at 315 parts per million in 1958 and reaching 385 parts per million in 2008. Second, a regular wiggle showing a yearly cycle of growth and decline of carbon dioxide levels. The maximum happens each year in the Northern Hemisphere spring, the minimum in the Northern Hemisphere fall. The difference between maximum and minimum each year is about six parts per million. . .

At every latitude there is the same steady growth of carbon dioxide levels, but the size of the annual wiggle varies strongly with latitude. . .

The only plausible explanation of the annual wiggle and its variation with latitude is that it is due to the seasonal growth and decay of annual vegetation, especially deciduous forests, in temperate latitudes north and south. The asymmetry of the wiggle between north and south is caused by the fact that the Northern Hemisphere has most of the land area and most of the deciduous forests. The wiggle is giving us a direct measurement of the quantity of carbon that is absorbed from the atmosphere each summer north and south by growing vegetation, and returned each winter to the atmosphere by dying and decaying vegetation.

The quantity is large, as we see directly from the Point Barrow measurements. The wiggle at Point Barrow shows that the net growth of vegetation in the Northern Hemisphere summer absorbs about 4 percent of the total carbon dioxide in the high-latitude atmosphere each year. . .

When we put together the evidence from the wiggles and the distribution of vegetation over the earth, it turns out that about 8 percent of the carbon dioxide in the atmosphere is absorbed by vegetation and returned to the atmosphere every year. This means that the average lifetime of a molecule of carbon dioxide in the atmosphere, before it is captured by vegetation and afterward released, is about twelve years. This fact, that the exchange of carbon between atmosphere and vegetation is rapid, is of fundamental importance to the long-range future of global warming, as will become clear in what follows. Neither of the books under review mentions it.

We often hear about the longevity of CO2 in the atmosphere. The conventional account is that it endures for over 100 years. This is based on chemical decay rates in the atmosphere. The more important issue seems to me to be the carbon cycle which runs 9 or 10 times as fast, and so provides us more opportunities to intervene. Keeping a larger fraction of the CO2 drawn down each year from being returned to the atmosphere would reduce concentrations.

Nordhaus just sticks to the economics. In Dyson's words:

The main conclusion of the Nordhaus analysis is that the ambitious proposals, "Stern" and "Gore," are disastrously expensive, the "low-cost backstop" is enormously advantageous if it can be achieved, and the other policies including business-as-usual and Kyoto are only moderately worse than the optimal policy. The practical consequence for global-warming policy is that we should pursue the following objectives in order of priority. (1) Avoid the ambitious proposals. (2) Develop the science and technology for a low-cost backstop. (3) Negotiate an international treaty coming as close as possible to the optimal policy, in case the low-cost backstop fails. (4) Avoid an international treaty making the Kyoto Protocol policy permanent. These objectives are valid for economic reasons, independent of the scientific details of global warming.

Economists quibble about Nordhaus' assumptions, especially discount rates (read the article if you need more explanation), but it is abundantly clear that by any measure we want the "low-cost backstop" scenario. What is it?

The fifth and last kind is called "low-cost backstop," a policy based on a hypothetical low-cost technology for removing carbon dioxide from the atmosphere, or for producing energy without carbon dioxide emission, assuming that such a technology will become available at some specified future date. According to Nordhaus, this technology might include "low-cost solar power, geothermal energy, some nonintrusive climatic engineering, or genetically engineered carbon-eating trees."

Or biochar! The fact that it is never discussed seems insane, but I suspect what it really means is that those who reason about these things are years behind current technology and practice. That's understandable since so much is changing so fast. I'm sure that there are many, many things that I have never heard of that deeply impact these subjects.

This is one of the reasons why I find the idea of political solutions of any sort to be ludicrous. By the time they can be enacted they are obsolete and counterproductive. As soon as they go into force they become the problem that most needs fixing. It's self punking. Literally doing nothing is better, though that's a theoretical null, an impossibility, since things are happening all of the time. People can't do nothing, though they can be stifled. In the end that's what political solutions amount to: preventing real solutions from being produced - by brute force.

Dyson concludes the Nordhaus review:

It is likely that biotechnology will dominate our lives and our economic activities during the second half of the twenty-first century, just as computer technology dominated our lives and our economy during the second half of the twentieth. Biotechnology could be a great equalizer, spreading wealth over the world wherever there is land and air and water and sunlight. This has nothing to do with the misguided efforts that are now being made to reduce carbon emissions by growing corn and converting it into ethanol fuel. The ethanol program fails to reduce emissions and incidentally hurts poor people all over the world by raising the price of food. After we have mastered biotechnology, the rules of the climate game will be radically changed. In a world economy based on biotechnology, some low-cost and environmentally benign backstop to carbon emissions is likely to become a reality.

The Zedillo book is a collection of essays presenting a wide variety of views of the post-Kyoto world. It provides Dyson an opportunity to discuss the misbehavior of climate scientists and politicians. They are not interested in science, discovery or knowledge. They are on a mission and all objections are ignored. Environmentalists, of course, get a few whacks too.

Much of the public has come to believe that anyone who is skeptical about the dangers of global warming is an enemy of the environment. The skeptics now have the difficult task of convincing the public that the opposite is true. Many of the skeptics are passionate environmentalists. They are horrified to see the obsession with global warming distracting public attention from what they see as more serious and more immediate dangers to the planet, including problems of nuclear weaponry, environmental degradation, and social injustice. Whether they turn out to be right or wrong, their arguments on these issues deserve to be heard.

Deserve doesn't seem to be the right word here. We need open and insightful discussion of all of these issues. Failure has consequences.

Update:

A Familiar Pattern

What do Real Climate and Joseph Romm do? Rather than engage the substance of the policy arguments, they go on the attack, with Real Climate using the term "b#ll&hit" and Romm "unmitigated disinformation." Of course the policy issues that they don't like -- discount rates, cost estimates, air capture -- all come from Nordhaus, not Dyson. But rather than engage the substance they viciously attack an individual.

I have no problem with attacking individuals, but it isn't a substitute for engagement with substance. When both are done I have no objection.

Update:

Derek Lowe says many of the same things, better.