Whether someone is serious about tackling the global-warming problem can be readily gauged by listening to what he or she says about the carbon price. Suppose you hear a public figure who speaks eloquently of the perils of global warming and proposes that the nation should move urgently to slow climate change. Suppose that person proposes regulating the fuel efficiency of cars, or requiring high-efficiency lightbulbs, or subsidizing ethanol, or providing research support for solar power—but nowhere does the proposal raise the price of carbon. You should conclude that the proposal is not really serious and does not recognize the central economic message about how to slow climate change. To a first approximation, raising the price of carbon is a necessary and sufficient step for tackling global warming. The rest is at best rhetoric and may actually be harmful in inducing economic inefficiencies. — William Nordhaus
If this chapter were widely read, the public understanding of global warming and possible responses to it would be greatly improved. — Freeman Dyson
What a combination — William Nordhaus’s new book, reviewed by the remarkable physicist Freeman Dyson for the New York Review of Books. In his essay “The Question of Global Warming” Dyson also reviews Global Warming: Looking Beyond Kyoto, edited by former president of Mexico Ernesto Zedillo.Dyson does a great job of abstracting the key conclusions from the Nordhaus study of five alternative policies. Here’s a brief summary - the policy values are expressed in constant $ trillions.
+17 Low-cost backstop policy
+3 Optimal policy
+1 Kyoto with US participation
0 Kyoto without US participation
0 Business as usual
-15 Nicholas Stern policy [of the Stern Review]
- 21 Al Gore policy
Hopefully you are now motivated to read the entire Freeman Dyson review, where you will learn the particulars of each of the above policies and how the DICE model evaluations are performed. Here’s how Dyson summarizes the Nordhaus conclusions:
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.
If you’re not ready to buy the book, then I recommend the 2007 Nordhaus paper which summarizes some of the content: The Challenge of Global Warming: Economic Models and Environmental Policy [PDF].
Reviewing Global Warming: Looking Beyond Kyoto, Dyson briefly visits the topic of suppression of scientists who are at variance with the “consensus position”, such as MIT’s Richard Lindzen vs. Potsdam University’s Stefan Rahmstorf.
In the history of science it has often happened that the majority was wrong and refused to listen to a minority that later turned out to be right. It may—or may not—be that the present is such a time. The great virtue of Nordhaus’s economic analysis is that it remains valid whether the majority view is right or wrong. Nordhaus’s optimum policy takes both possibilities into account. Zedillo in his introduction summarizes the arguments of each contributor in turn. He maintains the neutrality appropriate to a conference chairman, and gives equal space to Lindzen and to Rahmstorf. He betrays his own opinion only in a single sentence with a short parenthesis: “Climate change may not be the world’s most pressing problem (as I am convinced it is not), but it could still prove to be the most complex challenge the world has ever faced.”
Regarding the United Kingdom’s position, Dyson clearly disagrees:
The United Kingdom has made up its mind and takes the view that any individuals who disagree with government policy should be ignored. This dogmatic tone is also adopted by the Royal Society, the British equivalent of the US National Academy of Sciences. The Royal Society recently published a pamphlet addressed to the general public with the title “Climate Change Controversies: A Simple Guide.” The pamphlet says:
This is not intended to provide exhaustive answers to every contentious argument that has been put forward by those who seek to distort and undermine the science of climate change and deny the seriousness of the potential consequences of global warming.In other words, if you disagree with the majority opinion about global warming, you are an enemy of science. The authors of the pamphlet appear to have forgotten the ancient motto of the Royal Society, Nullius in Verba, which means, “Nobody’s word is final.”
In other words, if you disagree with the majority opinion about global warming, you are an enemy of science. The authors of the pamphlet appear to have forgotten the ancient motto of the Royal Society, Nullius in Verba, which means, “Nobody’s word is final.”
Dyson closes with his typically sound insights, arguing that science should remain an open forum, and not every environmentalist carries identical scientific conclusions:
All the books that I have seen about the science and economics of global warming, including the two books under review, miss the main point. The main point is religious rather than scientific. There is a worldwide secular religion which we may call environmentalism, holding that we are stewards of the earth, that despoiling the planet with waste products of our luxurious living is a sin, and that the path of righteousness is to live as frugally as possible. The ethics of environmentalism are being taught to children in kindergartens, schools, and colleges all over the world.
Environmentalism has replaced socialism as the leading secular religion. And the ethics of environmentalism are fundamentally sound. Scientists and economists can agree with Buddhist monks and Christian activists that ruthless destruction of natural habitats is evil and careful preservation of birds and butterflies is good. The worldwide community of environmentalists—most of whom are not scientists—holds the moral high ground, and is guiding human societies toward a hopeful future. Environmentalism, as a religion of hope and respect for nature, is here to stay. This is a religion that we can all share, whether or not we believe that global warming is harmful.
Unfortunately, some members of the environmental movement have also adopted as an article of faith the be-lief that global warming is the greatest threat to the ecology of our planet. That is one reason why the arguments about global warming have become bitter and passionate. 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.
Clearly Bjorn Lomborg would be one of the horrified — see this post.
It’s important to understand that the carbon fluxes implied by the seasonal cycle in Northern Hemisphere pCO2 are gross, not net, fluxes. That is, though they represent a large annual movement of carbon in and out of the terrestrial biosphere, it’s a roughly balanced flux and does not represent net sequestration of carbon. So the anthropogenic flux (fossil fuel emissions plus land-use change), though smaller than the gross biospheric fluxes is effectively a “one-way” flux. At least on the time scales of economic planning. For scale, the “balanced” flux in and out of the biosphere is about 60-70 gigatons carbon/year. The anthropogenic flux is currently estimated at just under 10 GTC/year.
The annual cycle Dyson cites is mainly a “deciduous” signal: net ecosystem respiration (due in part to decaying leaves) versus net ecosystem photosynthesis. Only net growth of tree trunks and branches, or carbon buried in soils or peats “counts” as sequestration in this cycle.
So any biotech solution would have to be a “tree-trunk” solution.
see:
Canadell, J. G., Le Quere, C., Raupach, M. R., Field, C. B., Buitenhuis, E. T., Ciais, P., Conway, T. J., Gillett, N. P., Houghton, R. A., and Marland, G., 2007, Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks: Proceedings of the National Academy of Sciences, p. 0702737104, doi:10.1073/pnas.0702737104.
and
http://www.globalcarbonproject.org/carbontrends/index.htm
see also:
http://www.grida.no/climate/vital/13.htm
for an illustration of the reservoirs and fluxes in the carbon cycle.
Will, many thanks for the great references. The UNEP Introduction to climate change link is especially good for lay folk as an overview of the exchanges.
And thanks for the clarification of Dyson’s seasonal flux comments. I interpreted his description in the same way as you outlined. I think what Dyson was after was to get a handle on the rate at which carbon could theoretically be removed from the atmosphere by some future geo-engineering approach. He wrote:
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.
In this back-of-the-envelope estimation of the first derivative Dyson ignored the seasonal atmosphere-ocean exchanges. Why?
Steve asks: “In this back-of-the-envelope estimation of the first derivative Dyson ignored the seasonal atmosphere-ocean exchanges. Why?”
A number of reasons.
The atmosphere-ocean exchanges variability are not only due to biology, but also due to thermodynamics. Basically colder water can hold more CO2. So the seasonal cycle of ocean-atmos. exchange is controlled not only by growth of marine plants but by seasonality of temperature, mixed-layer depth and other dynamic variables.
The seasonality of o-a exchange is not as simple to characterise in terms of seasonality because the Southern Ocean plays such a big role and of course its seasonality is in the opposite sense to the Northern Hemi. Some of the most important areas of o-a exchange are modulated by by processes like upwelling which do not correspond clearly to either N or S Hemi. seasonality. Examples include monsoonal upwelling zones in the Arabian Sea.
Also biomass in the ocean is labile (short-lived). That is, it’s turned over much more than terrestrial biomass. Even though ocean productivity plays a big role in the global carbon cycle, marine biomass (or standing stock, or inventory) is orders of magnitude smaller than terrestrial biomass. There are no “trees” in the ocean and its ecosystems are dominated by planktonic micro-algae whose lifespans are measured in weeks or months (even the dramatic kelp “forests” off Tasmania and the US West Coast do not account for very much biomass). Proposals like iron fertilization that seek to stimulate ocean plant growth would not work by storing carbon as biomass, but by storing it as dissolved carbon dioxide (mainly bicarbonate ion) in the deep ocean. The carbon would be transferred to the deep ocean as biomass, but it would be quickly converted to dissolved CO2 by decomposition. So it’s a somewhat different system.