Flying Offsets

Joe Romm claimed that the real name for carbon offsets is “carbon rip-offsets” because they are all rip-offs. But the high energy-to-weight and rapid-fueling requirements for aviation fuel means that there are currently no usable substitutes, and there is very little we can do to reduce the carbon emissions of flying other than to not fly. Isn’t there some way we can confidently mitigate our air travel emissions?

Ultimately, a true offset will either put carbon back into the ground in a long-lasting form such as coal, oil, or charcoal; or it will reduce the amount of carbon that would otherwise have been dug-up and burned. The first is hard to do, and the second is hard to verify. But M. Sanjayan suggested an approach that makes good sense to me: giving away energy efficient lighting on his trips. The bulbs offset carbon by reducing the energy used to provide light, increasing what I call “energy performance”; providing the same energy services but with less energy. He suggested CFL’s, but LEDs are now in mainstream production and offer an even better solution.

I wondered, how many LEDs would I have to buy and give away to offset a given flight? The amount of carbon dioxide produced in the generation of electricity varies around the world, but in the USA the EPA tells us we average about 0.55 kg per kWh. On a visit to my local hardware store this week, I found 60 watt replacement LEDs for $13. These use only 9.5 watts of electricity and produce the same light as a 60 watt incandescent bulb. They are rated to last 25,000 hours.

We see that over 25,000 hours, a 60 watt bulb will use 1,500 kWh of electricity and the 9.5 watt LED will use 238; a difference of 1,262 kWh. Using the U.S. average of 0.55 kg per kWh, this means that replacing a 60 watt incandescent bulb with this LED will reduce electric power carbon dioxide emissions by 694 kg.

How much carbon dioxide do I emit on a flight? Terrapass, a seller of “offsets”, provides a calculator to estimate this number. They indicate that for a Los Angeles / New York roundtrip, each passenger creates 873 kg of carbon dioxide emissions.

It looks like I can offset my carbon emissions from a round-trip cross-country flight by buying and giving away two 9.5 watt, 60 watt replacement, LEDs to someone who will use them to replace incandescents. A significant virtue of this approach is that it is verifiable to me: I know I bought the bulbs; I know I gave them to someone who installed them; and I know they will reduce electric power consumption while providing the recipient with the same energy service (lighting) that they previously enjoyed and saving on electric bills in the bargain. I don’t have to worry about whether the offset company is honest, or how much of my donation is actually going towards an offset, or whether it is really an offset. And, as Sanjayan says, it’s a fun way to make friends at your destination.