Cars and Carbon

Barak Gila

March 2021

In America, driving is super convenient, and sometimes hard to avoid. Unfortunately, cars have a variety of costs that are externalized, borne not by the driver but by their local community and the environment as a whole. Incentives are good: if it were more expensive to drive and to park, more folks would seek out alternatives.

While there's no replacement for public policy change, I decided to partially align my own incentives. I'm donating to Project Vesta with the intention of offsetting the carbon emissions associated with my driving and flying retroactive to the start of 2020. I'm doing this because I think climate change is an important medium-term threat, and this may encourage me to drive less.

I start with an anti-car screed intended not to guilt-trip anyone (I have used and continue to use cars) but rather to inform you of their downsides and motivate my decision to try to reduce my driving with incentives. If you're not interested in being urbanist-pilled, feel free to skip ahead to the section about offsetting generally or through Project Vesta specifically.

Cars are more expensive than you think, and we're all paying the price.
What does it cost to drive to dinner downtown?
  • Narrowly, a 20 mile round-trip drive downtown in a 30 mpg compact SUV costs $2.40 if gas costs $3.60 per gallon.
  • Add around $2 for street parking, or more for garage parking, if you're lucky enough to live in a city that charges for parking.
  • The IRS, an organization not known for its generosity, allows deducting $0.56 per mile on taxes, much more than the $0.12 per mile gas costs as calculated above. That's because depreciation, maintenance, and insurance are also substantial costs of vehicle ownership. At that rate, you'd need to spend $11.20 plus parking for that 20-mile trip, a price point that might encourage you to take the train instead.
  • Of course, it's possible to achieve lower per-mile costs, for example with a fuel-efficient, cheap car, though the true cost is still much higher than the cost of fuel. However, depreciation, maintenance, and insurance are invisible, and they are somewhat fixed costs. In other words, once you own a car, you have strong incentives to use it because you're already paying for some insurance and depreciation regardless.
Chart of cost of car ownership

Fuel is only a fraction of the true cost of car ownership. Costs like depreciation and financing are invisible. source:

Unfortunately, the above doesn't include external costs of car ownership and usage. In America, we've designed our entire country around cars to the extent it's almost impossible to imagine any other way of doing things. Societal costs of car supremacy include negative impacts to our local community, and to the global environment.

Once you start interpreting the built environment as horrible hacks to facilitate the omnipresence of cars, it's impossible to unsee.
Our car culture is dangerous to to all of us, and particularly harms underrepresented groups and vulnerable demographics.
Align public and private incentives
Most of the above problems were governmental and they'll need public solutions.

We'll need public actions more radical than the Green New Deal (which focuses on jobs and public investment) to address them. As a start, I support carbon taxes, bus-only lanes on urban and suburban freeways combined with frequent, convenient service, following in Amsterdam's footsteps to transform our cities to prioritize everyone but cars, and then making it more expensive to use cars with congestion pricing and increased registration/per mile fees.

I'll start by changing my own incentives around driving and flying.

Just as plant-focused restaurants might open in a community with many vegans and vegetarians, I hope individual action can encourage a public policy change. I've already made some changes in my behavior since I learned more about urbanism (like getting around the Peninsula by biking and taking Caltrain, rather than always driving), but it's good to align my incentives along these lines.

Relatedly, I believe climate change is super important, and among the most important reason to reduce our car usage. So, I decided to start by partially offsetting the carbon emissions of my driving and flying. (I'm excluding non-carbon externalities, costs associated with car/plane manufacturing and disposal, and other indirect costs.)

Concretely, I'll pay to offset 0.3 kg of carbon emissions per car-mile, and 0.15 kg of carbon emissions per plane-mile.
  • The EPA calculates vehicle emissions as 9 kg of CO2 per gallon, and the average mpg of cars I use is 30 mpg. In theory, I'd divide the resulting 0.3 kg/mile emissions by the total number of people in the vehicle (excluding Uber drivers etc). In practice, this is annoying to do and I'm overestimating all trips as solo instead.
  • I'm using this calculator from the United Nations' ICAO for plane emissions. Longer flights are more efficient, so I'm averaging the 0.075 kg/plane-mile it outputs for SFO-MEL and the 0.225 kg/plane-mile for SFO-SLC.
Chart of CO2 per passenger-mile for different modes of transport

You may be surprised that cars generally emit more than planes. For full electric cars, emissions depend on the electricity source, but due to their batteries, electric car manufacturing emits 15-68 percent more CO2 than gas-powered car manufacturing. source:

Fight climate change with carbon capture
I decided to donate to Project Vesta, which uses olivine (a rock) placed on beaches to absorb carbon long-term, to offset my carbon emissions.

I briefly considered tree-planting organizations, but I'm concerned it's not as scalable or guaranteed. If the forest burns down, the sequestered carbon gets released, whereas the carbon absorbed from olivine eventually becomes limestone, and it's supposed to stay absorbed for millenia.

Climeworks is another organization I considered. Like Project Vesta, it's working on scaling a technology to directly capture carbon from the air. Also like Project Vesta, it's one of four organizations Stripe donated to in their first phase of climate action (to be honest, I mostly outsourced due diligence to Stripe). However, Project Vesta is a nonprofit, so it's twice as cheap for me to give to them. One downside is that while Climeworks directly attributes some removed carbon to your donation (at a price of $1.10/kg carbon), Project Vesta is a bit more exploratory. At this stage, most of their costs are from measuring their carbon and other ecological impacts of their technology. They quoted Stripe $0.075/kg, and quoted me $0.75/kg.


Project Vesta hopes that this rock, each kg of which can absorb 1 kg CO2 from the atmosphere, will be a key to addressing climate change. source:

$0.75/kg translates to $0.225/car-mile and $0.1125/plane-mile using the above numbers.

Retroactive to the beginning of 2020, I've driven around 10,000 miles and flown 15,000 miles. That comes out to $4000. I recently gave $10,000 to Project Vesta, which I'll budget as covering 2020 through all of 2021.

Call to action

Thanks for reading! Let me know of any errors, comments, and especially if I influenced your decision to donate to Project Vesta or anywhere else! You can also find me on Twitter @barakgila.

Thanks to Hansen and Neil for reviewing this piece.