Part of a series where I try to calculate the carbon footprint of my life.
As noted earlier, I have committed to try living a 1.5° lifestyle, which means limiting my annual carbon footprint to the equivalent of 2.5 metric tonnes of carbon dioxide emissions. That works out to 6.85 kilograms per day.
There are a number of hot spots in our carbon emissions, where we get the biggest bang for the buck in our changes:
Focusing efforts to change lifestyles in relation to these areas would yield the most benefits: meat and dairy consumption, fossil-fuel based energy, car use and air travel. The three domains these footprints occur in – nutrition, housing, and mobility – tend to have the largest impact (approximately 75%) on total lifestyle carbon footprints.
Before I can really start this 2.5 tonne diet, I have to figure out what the emissions of each choice actually are. So let's start with local transportation. I live in a hundred year old "streetcar suburb" in midtown Toronto and am fortunate in having access to just about every form of transportation, so I have lots of choices. I also work mostly from home, so my commuting distances are pretty low, so transportation probably won't be nearly the problem for me that it would be for others.
UK activist Rosalind Readhead has done a lot of research for her scary 1 tonne diet, and points me to a number of sources quoted here. Most of the research has been done in Europe and is in metric measurements, and I apologize in advance to American readers who are not comfortable with metric but I am going to generally stick with them.
There are two kinds of emissions that we have to count to really get to our footprint: the operating emissions (how much carbon is produced actually doing something) and the embodied emissions, or what I call the upfront carbon emissions, that come from making the thing that's doing the work. Upfront emissions are hard to calculate accurately; you might be able to figure out how much carbon was emitted, but then you have to amortize them over the expected life of the thing, in this case a vehicle.
Take this analysis of the comparable emissions between a Tesla Model 3 with an American made battery, compared to conventional vehicles. The Carbon Brief (CB) people total up the upfront carbon emissions (UCE) of the basic car (dark blue), the battery (light blue), and the fuel cycle, "which includes oil production, transport, refining, and electricity generation." The Tesla is always better than the average Euro car. But the UCE calculations are based on the car being driven 150,000 km; as we have seen, a Tesla might last twice that. The UCE of the battery might be wildly over-estimated, and is dropping all the time. The average Euro car is also going to be way lower than the the average American car.
This is a fundamental problem with UCE calculations, and these should be taken as guidelines, a place to start. But generally I believe that the Tesla is better and the cars are worse than the Carbon Brief numbers indicate. And, after my recent math fiasco, everything I do with numbers should be checked twice.
Readhead pointed to a study by the European Cycling Federation (ECF) that came up with other numbers in a 2011 study quantifying the CO2 savings of cycling. Between the two, I will be using these numbers for my spreadsheet calculations:
The first thing that is obvious is that driving a conventional car, even the short 15km round trip to where I teach, is pretty disastrous, blowing more than half my daily budget. The average American daily commute of 16 miles or 25 km blows the whole thing, and that's driving a little Euro car. (I have not been able to find good data on American SUVs and pickups yet). I am glad I have an e-bike.
Next: the food that I eat.