James Hansen is the man who has been right about (almost) everything on climate change, and before everyone else. Google Scholar shows some 690 citations of his 1981 paper Climate Impact of Increasing Atmospheric Carbon Dioxide. Hansen is the person who worked out the 350 ppm CO2 concentration goal, and in this book he explains the how and why of that figure.
Hansen brings excellent knowledge and exposition of the science. Since I last studied this, there has been a revolution in paleoclimate research, and we now have data on the history of the earth's climate that provides data on how various “forcings”—that is, things that warm and cool the planet—affect the planet's climate. The evidence is, as we keep hearing, overwhelming. It turns out that it is has been known since 1976 what causes ice ages: in 1976 Hays, Imbrie, and Shackleton published a paper validating Milanković’s early 20th century celestial mechanics hypothesis. This is fascinating, and it also shows that earth's climate is, in fact, responsive to small changes in solar irradiation (insolation.)
Hansen explains how we are moving towards tipping points, after which climate change will become self-sustaining. He talks about likely tipping points—ice sheet collapse and methane clathrate upwellings. He also offers stories of the governmental decision making processes—Dick Cheney does not come out looking good. And it turns out that Lindzen, now the only major figure in climatology who argues against global climate change, also argues against a link between tobacco use and lung cancer. He claims to doubt the statistical evidence though it is overwhelming, just as the industry-funded flacks claimed, decades ago. It seems he has swallowed the deceptions of the tobacco industry and now the fossil fuel industries, and so destroyed his scientific credibility.
Then we come to Hansen's proposed political and technological solutions. First, he advocates quickly abandoning the use of coal as the only feasible way of meeting the 350 ppm goal, pointing out that it is not likely that the world will leave the oil in the ground for some years yet. He points out that solar power has not taken off as hoped, and so, he argues for nuclear power and, in fact, for fast neutron breeder reactors on the grounds of long-term availability of fuel and the relatively short half-lives of waste products—centuries rather than millenia. He argues for a carbon tax, rather than an emissions trading system.
Now I turn to activist Bill McKibben's Eaarth. The first part of the work reiterates some of the evidence for climate change and cites Hansen's 350 ppm goal. He also makes the point that we no longer live in the world we took for granted, but instead a harsher world, hence the title of the book: Eaarth. In his solutions he turns in a different direction than Hansen, arguing for a rebirth of village life, and in his final section has expresses doubts of such a system, pointing out that it has historically been parochial and sexist, and hopes to preserve the internet to leaven it.
What do I think?
- The scientific evidence for anthropgenic global climate change is overwhelming. I was not aware that planetology had come so far, and this is not simply a matter of debatable models but concrete paleoclimatological data.
- I like McKibben's way of thinking about the changes: that we no longer live on the Earth of history and legend, but instead on the new world, Eaarth. (“We are now leaving the Holocene. Please put your seatbacks up and return your tray-tables to the upright and locked position.”)
- I consider that the people running Hansen's fast-neutron reactors will be the same people who now run the oil companies. There is also a genuine risk in the production of so much weapons-grade fissionables. That's worrisome. My thought on the need for concentrated energy is that we might do well to start funding research on multiple alternatives: large-scale solar like the StratoSolar proposal as well as nuclear, but most importantly we need to get started.
- I am unconvinced by McKibben's village life model. Humans are naturally nomadic apes, and village life is an outgrowth (so far as is known) of limited resources and authoritarian impulses. I would prefer we avoid recreating subsistence lifestyles and instead seek new social forms.
- My overall intution is that we can—if we control our population—actually have a pretty comfortable lifestyle if we want it. We can have airships, wind-powered ocean-going ships that only occasionally run their engines, solar-electric rail, and so on. What we can't keep doing is basing personal transportation on personal automobiles and fast air travel as a matter of routine; we will have to find some other way to scratch the itches those things satisfy.