Our Approach to Carbon Offsets

For the past year our family of four has been traveling around the world. And while we’ve been doing everything in our power to cut down the typical waste travelers produce, the fact of the matter is that we have had a huge negative impact on the climate with all of our plane flights.  So what, if anything, can be done about this?

Our Quick Take on Carbon Offsets.png

Here we lay out for you how we’re thinking about carbon offsets after doing some research on the subject.  We’ve always felt that talking about carbon offsets was like wading into murky water, so our hope is that by sharing what we’ve learned will make it a little clearer for you to wade through for yourself.  

Can we mitigate the environmental damage done by our flights?

The short answer, we think, is no, not really. It’s one thing to plant trees at ground level, it’s another to spew a noxious cocktail of airplane emissions at 30,000 feet. It’s like eating 3 big macs a day and then trying to exercise it off. Yeah, you can get calorie neutral, and exercise is great for you, but the free radicals and mixture of terrible fats you’ve introduced can’t be totally erased. So, the following discussion about offsetting carbon is like the exercise analogy- it’s what we can do to try to mitigate the damage already caused, but the effect will not be net neutral. This is why the first steps should always be to try to fly less and use other forms of transport and reduce your footprint, but alas, it’s too late for us to go back and erase what we’ve done.

Figuring out how much carbon you’ve created:

Using ourselves as an example, for our 13 flights around the world this past year, we have totaled about 8,000 pounds of CO2 for each passenger. That makes 32,000 pounds, or 16 tons of CO2. Multiply that by four family members and you get 64 tons. Holy crap!

I tried a variety of calculators and eventually decided this one through the International Civil Aviation Organization (ICAO) was best because of the level of detail it dug down into with regards to individual segments, airplane types used, etc. In addition, we used Atmosfair, which includes other factors such as ozone formation and contrails to get a bit more of a complete picture. If you use their analysis and include nitric oxide (NO) and other factors, the amount of CO2 equivalent triples- in our case to about 200 tons.  Wow.

Here is an example of the breakdown of our flight from San Francisco to Santiago, Chile (via Miami) on the Atmosfair website:

CO2 CalculationsSF-Miami-Santiago.png

How do programs that ‘offset carbon’ work?

Basically, you give money to an organization that has a carbon emission reduction program. These come in two flavors- they either capture and store carbon or do something that prevents emissions. “Capture and store” usually means planting trees or preventing them from getting cut down (like Cool Earth, who we talk about below).


“Preventing Emissions” is usually in the form of installation of solar or wind to prevent the use of dirtier fuels, almost always in the developing world. Atmosfair gives an example on their website of replacing diesel heating of water in settlements outside of Cape Town with solar water heaters.

Both approaches seem to have their benefits and we aren’t sure which is better.

How much does it cost to offset carbon?


This varies widely depending on where you look. Most sites that are dedicated to the idea of selling offsets (or asking for donations in a way that is tied to amount of carbon produced) use numbers in the $10-$20 per ton range. Gold Standard which is a pretty reputable source, sells carbon offsets for $13 per ton. Atmosfair ‘charges’ $23 Euro per ton, which is the highest we’ve found (and remember they count all the other nasty chemicals, not just carbon, so their calculated CO2 per flight is 3x as much).

As you can see from the calculation on our flight from San Francisco to Chile (which was over 12 hours of flying time) was 57 Euros each, or just over $66 USD, which, even though this is by far the highest estimate, still seems pretty dang cheap.

Who to donate to?

The idea of ‘buying’ offsets is kind of weird (unless you are a corporation in a cap and trade situation) because what are you actually buying? There are a ton of places where you can punch in your flight or carbon production info, give them a corresponding amount of money, and then they will offset through their programs. But since you and I aren’t trying to buy certified credits to Cap and Trade, we can broaden our search for great charities that do climate change work.

Having looked at a bunch of options, we decided to give money to Cool Earth this time around. Cool Earth is a UK based charity that protects vulnerable rainforest around the world through a system of micro-grants to local people. Cool Earth measures the amount of CO2 they directly protect at $1.34 per ton of carbon offset, which is 10 times more cost-effective than most charities, and if you count all the forest that they block off from deforestation that number comes down to $0.34 per ton of carbon. The article that ended up convincing us by laying out all of these numbers (which is from a very cool site that attempts to measure and compare the impact of different charities) is here.  Next time we might give to a solar hot water project (which has higher impact per dollar than solar photovoltaic or wind usually) or a climate action lobby group (which has a higher potential benefit but is also higher risk, because they may end up not changing any legislation).

So where does that leave us?

Because there is such a range in how you calculate both carbon production (do you include NO and other gases? Chemtrails?) and how much it costs to offset it (a crazy range of $0.34/ton to $27/ton).  Just covering the CO2 (64 tons) and using the cheapest numbers from Cool Earth ($0.34 per ton) you get an unbelievably low $22 total to offset everything; while using the higher Atmosfair CO2 equivalent (200 tons) and their much more expensive offset price ($27/ton) its a staggering $5,400. I think the most accurate for us would be to cover 200 tons of carbon at the Cool Earth rate of $1.34 per ton would bring us to $268 to offset the carbon produced by our family of 4 over the year around the world.

In the end we decided to give $1,000 to Cool Earth. Not because that number is what we think will perfectly offset our emissions, but because it is what we feel like we can afford right now. This brings us to the biggest piece of advice I would give about this process and what we’ve concluded - just give as much as you can to a charity that you think does good work. If calculating your footprint and donating enough to mitigate that works for you, then great. It would be even better to skip all the flights and still ‘offset’ as much as you can.


Any thoughts, questions, concerns?  Please don't hesitate to reach out!