NPR science correspondents take questions from listeners on climate change — an excellent idea.
One question they answer I heard asked to Bill McKibben just two weeks ago, about the effect of population on global carbon emissions. McKibben made a strong point that NPR glosses over in their answer.
Most of the population growth in the world is occuring in the third world. Nations that emit a lot of carbon–such as ours–are growing relatively slowly. McKibben pointed out that in places like Tanzania, folks emit very little carbon; in fact, he said, the average American emits more in two days than most folks in Africa emit over the course of an entire year. So the real danger is not so much population growth, but that other peoples will emulate our way of life.
But here’s another contrarian question that comes up a lot:
And my question is what is the advantage to trading in my car and buying a hybrid, since someone else will be driving my car, and since there is a lot of energy expended in building a hybrid – a lot of carbon dioxide emissions, I would assume.
— Celeste Budwitt-Hunter of Houston —
Robert Siegel: Now, Jennifer, as you’ve told us, that factory that is making the hybrid back in Japan is using up a lot of energy and is sending up a lot of emissions. So how does the equation work out?
Jennifer Layke: Well, actually, from the perspective of a life cycle of emissions for an automobile, the majority of the emissions actually occur in the use phase, so it makes a big difference what you decide to drive.
So an average car in the United States, if you look at an average car for a sports utility vehicle, for example, you emit a ton of CO2 when you drive about 1,300 miles – that’s 1,300 miles; we drive about 12,000-14,000 miles a year. An average hybrid will emit one ton if you drive 6,000 miles, so it’s quite a significant difference in terms of your annual driving.
Kit Stolz 