Thursday, August 19, 2004

Not So Simple

Like other groups of highly educated individuals of superior intelligence, professional scientists tend to be more liberal than the American average—a fact documented in many places, for example, the Bell Curve. Whatever their political proclivities, however, scientist are not given to yelling and hooting. Indeed, as I can testify from many years of personal experience as a technical editor, it is very, very difficult to get a scientist to make an unguarded, unqualified statement, even when the facts warrant it. These folks have grown up in a system in which nobody has a right to an opinion, and every published utterance must be vetted in advance by well-informed critics who are often professional rivals. Meanwhile, the economic situation of scientist also encourages cautious speech. Those who best know what they are talking about work for businessmen and politicians who generally don’t know very much at all. Telling the truth in an asylum run by the patients requires continuous tact and, as the man said, abeunt studia in mores, i.e. you get used to it. All of which makes the current political activism of the science establishment all the more remarkable. The most recent issue of SCIENCE (13 August) is a case in point. The issue features a special section on the hydrogen economy that Bush has promoted as a pat answer to energy and environmental problems associated with global warming. The clear message of the issue is that the hydrogen initiative is politically useful but crucially flawed.

Hydrogen power may have a role in the fairly distant future, but it is hardly a panacea. Hydrogen has to be generated by processes that require energy and produce carbon dioxide. If we make hydrogen by burning coal, we’ll have to figure out how to somehow sequester the resulting CO2 to make net progress towards carbon emissions reduction. Carbon sequestration is a monumental technical problem. And producing hydrogen promises to be a very expensive proposition. Meanwhile, hydrogen presents many other technical challenges. To mention one simple but hard to solve problem: hydrogen is very light. Storing enough hydrogen to power a car for 300 miles of operation would require a fuel tank eight times larger than a normal gas tank even if the hydrogen were pressurized to 10,000 pounds per square inch. There are other options: liquefying the hydrogen or absorbing on in carbon nanotubes or hydrides but nobody knows if these techniques are practical or affordable.

Even if the hydrogen option pans out, it isn’t rational to pursue it in lieu of other measures against the looming problem of global warming. As Donald Kennedy wrote, “Our attention is deflected from the hard, even painful measures that would be needed to slow our business-as-usual carbon trajectory. Postponing action on emissions reduction is like refusing medication for a developing infection: It guarantees that greater costs will have to be paid for.”

Note: The articles in SCIENCE aren't available on line without a subscription.

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