I’m a fierce carbon tax advocate, as Grist readers know. But what most upset me about the interview with Stephen Chu in last Sunday’s New York Times magazine wasn’t the energy secretary’s disavowal of an Obama carbon tax:

Q: Many environmentalists believe that a permanent carbon tax would be the most efficient means of spurring carbon-reducing technologies.
A: Well, we’re not talking about a carbon tax. President Obama and I are not talking about a carbon tax.

Help Grist raise $25,000 by September 30 to further advance our climate reporting

Chu and biking colleagues.Chu (center) with cycling colleagues at the Lawrence Berkeley National Laboratory.We all know Secretary Chu has to toe the party line, which, for now, is cap-and-trade. No, what hurt was this:

Q: Is it true you don’t drive a car?
A: My wife does, but I no longer own a car. Let me just say that in most of my jobs, I mostly rode my bicycle.
Q: And now?
A: My security detail didn’t want me to be riding my bicycle or even taking the Metro. I have a security detail that drives me.
Q: How do you feel about adding carbon emissions to the air?
A: I don’t feel good about it.

Grist thanks its sponsors. Become one.

“I don’t feel good about it”? The guy is in agony over it! Chu is an avid, lifelong bicyclist — the interviewer didn’t have to ask, Chu volunteered that fact — and now he’s sealed up in a Chevy Tahoe. Ouch!

What followed was even worse:

Q: I guess the President wants to keep you alive.
A: My wife is in favor of that as well.

Double ouch. Chu knows — he must know — that all those years he was cycling to work, nothing kept him alive as well as bicycling.

Grist thanks its sponsors. Become one.

That’s right. Phone-addled SUVers may rule the roads, but Chu, like the rest of us getting around on two wheels, is extending his longevity every minute he spins the pedals. The cardiovascular exertion, the mental acuity, the sheer engagement with the world that cycling demands add more to the cyclist’s statistical life span than the risk of a fatal or disabling injury-accident takes away.

British researcher Mayer Hillman was the first to calculate, in the early 1990s, just how much the health benefits of regular cycling outweigh the actuarial loss of life from road accidents. In his breakthrough report for the British Medical Association, Cycling: Towards Health and Safety, Hillman found that even in Britain’s anti-cycling road environment, each minute of lost life expectancy from the elevated probability of crash injury or death to some cyclists was offset at least 10-fold by the increased longevity from improved health of other cyclists.

More recently, a team of epidemiologists who monitored the health of 30,000 Danish adults over a 15-year period found a 28% lower mortality rate among cycle commuters.

Let’s translate that Danish finding to the U.S. From standard life-expectancy tables, a 61-year-old non-cycling American adult, like Chu, has a 1.0% chance of dying in the next 12 months — meaning that among 130,000 such people, 1,300 will die. Whereas, according to the Danish study, if those same 130,000 61-year-olds were cycle commuters, 28% fewer of them — 364 less — would die. Yet in New York City, where I live and am one of an estimated 130,000 daily cyclists, “only” 20 of us are killed in crashes each year.

For relative oldsters like Chu (I’m five months older than the secretary, so I can call him that), we could double the cyclist deaths to 40, and still have 9 times less extra mortality attributable to cycling as avoided by it (40 vs. 364). And that’s not counting the crash risks from other ways of getting around – let alone the safety “dividend” each cyclist confers on others through the safety-in-numbers phenomenon (with more cyclists, the risk to each is diminished).

What to do? Simple. Mrs. Chu should march her husband into the Oval Office and say, “Mr. President, we ran the numbers, and sitting in that SUV is bad for Stephen’s life expectancy. Please let him ride his bike to work.” Mr. Obama, for good measure, can add a “carbon tax now” sticker to Chu’s helmet.