Environmentalists have long promoted hydrogen as a panacea for environmental and economic ills, including air pollution, climate change, and dependence on imported oil. But a new study by Caltech researchers published in the journal Science raises concerns that releasing large amounts of hydrogen into the atmosphere--which could occur if hydrogen becomes a common fuel--might itself pose risks, including damaging the ozone layer, altering global climate, and changing the growth rates of soil microbes.
Research on the environmental implications of widespread use of hydrogen is still in its infancy, and the Caltech results may or may not stand up to scrutiny by other researchers. Indeed, a few experts have already challenged some of the study's assumptions. Yet regardless of hydrogen's net environmental effects, the response to the study has already told us a great deal about whether environmentalists take their principles seriously.
A key tenet of modern environmentalism is the "Precautionary Principle." It takes many forms, but a common version, from a 1998 environmental conference, states "When an activity raises threats of harm to the environment or human health, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically."
If that's all it takes to spike new technologies, then the Science report should have sent environmentalists scrambling to deep-six the hydrogen economy before it can do any damage. But so far, the only environmentalist response I've been able to find came from anti-biotechnology, pro-hydrogen activist Jeremy Rifkin, who said "when you move into a new energy source you have to assume there's going to be some environmental impact" but that replacing fossil fuels with hydrogen "is our hope for the future." Whatever principles Rifkin used to draw these conclusions, the Precautionary Principle isn't among them.
That environmentalists are unprincipled about the Precautionary Principle should come as no surprise, since faithful and consistent application of the Principle is impossible. As legal scholar Cass Sunstein notes, "risks are on all sides of social situations. Any effort to be universally precautionary will be paralyzing, forbidding every imaginable step, including no step at all."
For example, many environmental activists believe the Precautionary Principle compels bans on genetically engineered food crops. But such a ban would itself run afoul of the Principle, by depriving the world's poor of cheaper and more nutritious food. Such "risk-risk tradeoffs" are part and parcel of all human endeavors.
Regulation can also create new "substitute risks" that offset some or all of the benefits of the regulation. The Food and Drug Administration wishes to ensure that no dangerous drugs enter the market. But safety reviews take time; the longer the drug approval process, the more people suffer or die awaiting new treatments.
Regulatory costs also create new risks by making goods and services more expensive, thus reducing people's effective income. Since higher incomes are associated with better health, expensive regulations can make us worse off overall, even if they work as intended.
Tradeoffs among risks and benefits are the norm in human affairs, and the Precautionary Principle provides no guidance on how to deal with them. Perhaps that's just the point. By selectively invoking the Precautionary Principle, environmentalists may appear superficially cautious while imposing huge, but hidden costs on humanity through bans on health-promoting technologies.
That the Caltech results haven't spurred environmentalists to scrap their dream of a hydrogen economy suggests that the "Precautionary Principle" is more of an Insincerity Principle. Rifkin rightly notes that any new technology, including hydrogen power, is likely to have unforeseen impacts. Hydrogen's future in the economy will depend on how its package of costs and benefits stacks up against alternatives, and that calculus will change with time as both environmental science and energy technology continue to progress. But talking about these types of tradeoffs brings us right back to traditional risk assessment--exactly what the Precautionary Principle is intended to preempt.
1. Tracey K. Tromp et al., "Potential Environmental Impact of a Hydrogen Economy on the Stratosphere," Science, 13 June 2003, 1740-42.
Jonathan Adler, "The Precautionary Principle's Challenge to Progress," home.earthlink.net/~jhadler/prec.html.
Ronald Bailey, "Precautionary Tale," Reason, April 1999, reason.com/9904/fe.rb.precautionary.shtml.
Indur M. Goklany, The Precautionary Principle: A Critical Appraisal of Environmental Risk Assessment (Washington, DC: Cato, 2001).
Kenneth Green, "Seeking Safety in A Dangerous World," Reason Public Policy Institute, August 1999, www.rppi.org/environment/ps261.html.
Cass R. Sunstein, "The Paralyzing Principle," Regulation, Winter 2002-2003, www.catoinstitute.com/pubs/regulation/regv25n4/v25n4-9.pdf.
Aaron Wildavsky, Searching for Safety (New Brunswick, NJ: Transaction Publishers, 1988).
Joel Schwartz is a visiting fellow at AEI.