Living on a carbon budget means coming up with an accounting system for carbon impacts where no accounting conventions exist . . . yet. Recently I dealt with two personal carbon accounting riddles.
Two weeks ago, my brother-in-law’s sailboat ran into rocks off Barnegat, New Jersey and started sinking (he was asleep and his friends were steering). Fortunately, the Coast Guard quickly came to the rescue, no-one was hurt much, and the boat can be repaired. But when my shipwrecked brother-in-law landed at our house for a few days he donated the contents of his boat fridge, including about three pounds of hamburger and kebobs to our home fridge. Also, last weekend, a neighbor offered about a cord of seasoned but unsplit white oak firewood from a tree that fell down a year ago on her property, and I couldn’t pass it up.
The beef represents about 75 pounds of CO2E (it was grass fed, but that doesn’t make much difference). I am very skeptical of the rationalization “that plane was flying anyway”or “that cow was already dead” for zero counting of carbon impacts, and I like to err on the side of inclusion rather than avoidance. My general rule of thumb is that “if you pay for it, it’s yours” and “if you choose it when you had a choice, it’s yours” so that plane flight is always on my tab, and the methane laden beef farts are also on my tab when there is a choice of beef or chicken or tofu at the meeting room meal table. My other rule of thumb is “if they are not on someone else’s carbon tab, they are on yours.”
My brother-in-law doesn’t keep a carbon tab. Actually I don’t know anyone personally besides myself who does. If he did, he would probably beat my 4T/year budget, since he lives on a small sailboat year round and almost never flies (he was headed south for the winter when his boat hit the rocks). I didn’t choose to have my brother in law leave his spoilable provisions in my house (he has since rejoined his vessel in New Jersey). These cows have already farted their last, and unlike the act of burning fossil fuels to run a car, eating the beef doesn’t add any new emissions. It might even offset some anthropogenic methane emissions associated with an all-garbanzo bean diet. Since I limit the amount of meat I eat for health as well as environmental reasons, I will probably end up choosing or buying less beef on other occasions in the next month, so this shipwrecked beef minimally reduces overall demand for beef. I think I can eat the beef before it spoils as a carbon-free windfall.
Speaking of windfalls, the firewood is a simpler problem. I think it is fair to count small-scale biomass wood heat as carbon neutral, particularly when you are burning deadwood. Burning deadwood can’t exceed the natural regeneration (and carbon recycling) rate of the forest, and leaving the wood to rot instead means that at least some of the stored carbon would be emitted as methane gas. So my windfall wood heat also counts as a carbon freebie. But I am counting the two miles of driving the Prius to move the wood on my carbon budget — works out to less than a pound of CO2.