(dithered images are better for mother nature)

Our 2019 Sustainability Report

Isabel Münter
Sanctuary Computer Inc
18 min readJul 29, 2020

In early 2020, we collectively decided that we’re going to refocus the studio on doing work that causes no major damage. Sanctuary team members find much more satisfaction by working on projects that “does little to no harm”, and our work is always better when the team is proud of the product.

This process starts by looking inward, and assessing the damage that we do in our day to day operations, simply by existing. Of course, the lion’s share of our responsibility comes from the products we help our clients release; and we’ll be doing our part to help guide new clients in the right direction, but at the same time, it’s our role to set an example and raise the bar for our peers.

As of today, Sanctuary Computer has pledged to offset 150% of our carbon emissions since our founding in 2015 (before the end of this year), effectively making us carbon negative.

Disclaimer #1: There’s debate around whether the terminology “carbon negative” is fair. The argument is that if we truly wanted to be carbon negative, we shouldn’t exist as a company in the first place, and we acknowledge that. We’ve decided to use this terminology however, because we think that every company should strive to pull more carbon out of the atmosphere than they emit — aiming for carbon neutrality is not sufficient.

Disclaimer #2: There are many carbon calculators online, but given their wildly varying results, we’ve instead decided (for most part) to manually calculate our carbon footprint, in pursuit of a more accurate result. This is our first time reporting on our sustainability data and we’ve done it to the best of our knowledge. If something doesn’t look right or you have suggestions on how we can improve, please get in touch!

In order to help communicate our motivations, and provide resources for others looking to do the same, please refer to our sustainability site here:

2019 — Our Footprint In a Nutshell

  • Sanctuary Computer grew from 9 to 15 people
  • We joined studios with XXIX (further growing our team to 19) in late December (their contribution is not accounted for in this report)
  • We went to ReactiveConf in Prague (our biggest carbon footprint), Likeminds, the Glass House, and a Ski Trip in upstate NY
  • Hugh flew to South East Asia a handful of times when working on The Light Phone II (another big carbon footprint for us)
  • We’re not usually a remote company (unless there’s a pandemic going on), so we continued to commute into our cozy Chinatown studio
admiring kay’s cat’s new bowtie

How we calculate studio emissions

In order to discover our carbon footprint, we used the Greenhouse Gas Protocol (GHG). If you’d like a deep dive into our research, we’re actively maintaining resources and an in depth breakdown of our process over here.

The GHG Protocol breaks your emissions into three “scopes”. Here’s ours:

Scope 1: Direct emissions from sources owned or controlled by the company

Sanctuary Computer does not produce any direct emissions (we don’t own a company vehicle, or have any onsite refrigeration, gas burning, or other such sources of direct emissions).

Scope 2: Indirect emissions from purchased electricity

Scope 2: Purchased & Consumed Electricity

We got our purchased and consumed electricity data from our provider Con Edison’s website where all of our historical data is stored. In 2019, we purchased and used 8,676 kWh electricity at our 2,500 square feet studio on Bowery, and we’re on the NYCW (NPCC NYC/Westchester) eGrid subregion.

In the table below, it states that on the NYCW (NPCC NYC/Westchester) eGrid the total CO2 emissions are 635.8 lb CO2/ MWh. That translates to 0.2884 kg CO2/ kWh. By multiplying 8,676 kWh (our purchase electricity) with 0.2884 (kg CO2/ kWh), our total electricity emissions is 2502.16 kg CO2. You can find our calculations here.

Source (p. 3): United States Environmental Protection Agency

👉 What have we learnt, and how can we do better?

Buy 100% Renewable Energy from our Con Edison. Our Bowery lease was up at the end of April, and we decided not to sign a new lease due to the pandemic. Once we find and move into a new studio space, we will be switching to 100% renewable energy with ConEd.

Scope 2: Emissions from Cloud Computing & Web Hosting

We have 2 classes of cloud computing — per-server based, or per-usage based. The emissions for each class are calculated differently.

👉 How did we convert to CO2e?

Unfortunately, none of cloud providers run on renewable energy (with a notable exception of Digital Ocean’s NYC1 region, which runs on Equinix. However, we’re treating it the same as non renewables for this study) — and some are usage based, meaning they don’t give information around the actual underlying servers running our code. As such, our estimates here start to become a little abstract — please reach out if you have a better way of conducting this study.

For now, here’s how we did it:

First — for a cloud server using non-green electricity, we assume 450 kg CO2e / year / server (source). This means we can calculate Digital Ocean & Heroku:

Digital Ocean:

  • 6x Cloud Servers = 2700 kg CO2
  • $1,375.35 spent
  • $1 emits 1.96 kg CO2

Heroku (including database servers):

  • 16x Cloud Servers = 7200 kg CO2
  • $3096.89 spent
  • $1 emits 2.325 kg CO2

Second — Vercel & AWS obfuscate server, or are usage based, meaning we can’t tell how many servers are being used under the hood. So! In order to calculate the emissions for the bare metal running these services, we use the most conservative figure above for dollars to CO2e — Heroku emits 2.325 kg CO2e for every dollar spent.

Amazon Web Services (Object Storage & CDN):

  • $550.02 spent x 2.325 = 1278.797 kg CO2

Vercel (Serverless Functions):

  • $38.08 spent x 2.325 = 88.54 kg CO2

Total CO2 Emitted: 11,263.29kg CO2e

👉 What have we learnt, and how can we do better?

Switch to a Renewable Energy Cloud Provider. Google Cloud & Azure both provide 100% green renewable energy options, and both providers offer all of the services that we require above. In addition, the math above is somewhat “handwavey”. By moving to a green energy cloud compute provider, we won’t need to apply as much guesswork any longer!

Scope 2: Emissions from Data Transfer at the Edge

In addition to hosting servers, we also facilitate the transfer of data to and from clients (like websites or apps), which is energy intensive. For the sake of this study, we’ve limited our data transfer analysis to data transfer at the edge.

Wholegrain Digital are leaders in this space, so we’ve decided to use the figures their Website Carbon calculator is based on:

Specifically, that’s:

  • 1.805kWh per GB transferred
  • 0.475 kg CO2e per kWh


The Cloudfront usage statistics only date back 3x months, so in order to get a yearly number for data transfer, we’re working against that sample set. That’s technically a big overestimation, because the lions share of this bandwidth actually spiked with the launch of a very popular project this year.

Source: Cloudfront Usage Reports

On average, we’re currently transferring 117.2805 GB of data via Cloudfront, or 42,807.3825 GB per year.


We only started adopting Vercel this year — so our bandwidth last year was virtually none. We have invoicing dates back years, so we were able to pull accurate metrics. In 2019, we used 7GB of data transfer.

Total CO2 Emitted:

👉 What have we learnt, and how can we do better?

Design our projects to be less data intensive. On average, our Studio Carbon Negative site emits 0.33g of CO2e on a cold-cache page load — according to Website Carbon, that’s cleaner than 78% of the page they’ve tested.

Additionally, that page runs on entirely renewable energy, meaning that the emissions are actually lower. There’s a lot we can do as creatives to build cleaner websites, and we’re excited to publish a technical teardown of our Studio Carbon Negative site later this year.

the sanctuary computer & human NYC ski trip, circa 2018

Scope 3: Indirect, upstream sources not owned or controlled by the company

Emissions from Manufacturing Laptops

Everyone at Sanctu works on a Mac, and Apple releases annual Environment Responsibility Reports as well as Product Environmental Reports for each of their products. This made it easy for us to figure out our carbon footprint from our laptops manufacturing and usage!

In our calculator, we’ve listed out each employee’s laptop model, their employed months at Sanctu in 2019, and their laptop’s embodied carbon. Employees at Sanctu either have a 13" MacBook Air (176 kg CO2 product life cycle emissions), 13" MacBook Pro (229 kg CO2 PLC emissions), or a 16" MacBook Pro (394 kg CO2 PLC emissions). We’re conservatively estimating that each laptop will last around 4 years on average (though in most cases longer).

Based on our calculations, the carbon embodied in our team’s work laptops (during 2019) made for a total of 839.19 kg CO2.

(A big, big thanks to Wholegrain Digital for leading the way here)

👉 What have we learnt, and how can we do better?

Owning your work laptop is eco friendly. Sanctuary’s employees use their personal laptops for work (and are offered to purchase them as a business expense pretax with their profit share). Given the nature of our work, and the fact that our coworkers own just one laptop for work and personal life is the most eco-friendly move.

Mobile Combustion Emissions

Sohee drives a Honda CRV 2007 to and from the ferry, which emits 404 grams per mile. Based on our calculations, this totaled 252 kg CO2 emissions in 2019.

Source: Fuel Economy

Employee Commuting

We first shared Wholegrain Digital’s Team Carbon Footprint with the Sanctu team to collect everyones commuting info. From there, we calculated each employee’s travel miles and number of trips per year that trip was taken.

We then estimated the CO2e per mile for the various transportation vehicles. The one mile CO2e is based on data from various sources, and in the case that sources provided different metrics (Xg CO2e per mile), we buffered and used the highercarbon emissions metric. Below we’ve linked the sources for each transportation option Sanctu’s employees use.

🚇 Subway

The New York City Subway, which is the most used form of transportation at Sanctu, emits 0.147 pounds (66.7 grams) CO2/ passenger mile.

Source: U.S. Department of Transportation Federal Transit Administration

Carbon emissions for subway commuting for all Sanctu employees in 2019 totals 964 kg CO2.

⛴️ Ferry

We’ve got two Sanctu people commuting into Chinatown on the ferry from New Jersey and Red Hook. The CO2e for a foot passenger on a ferry is 30.23 gram per mile (Source 1 (30.23 gram/ mile), source 2 (30 gram/ mile)).

Carbon emissions for ferry commuting in 2019 totals 228 kg CO2.


Other types of transportation options include walking and biking.

Carbon emissions for all Sanctu commuting in 2019 totals 1,194 kg CO2.

Electricity for Commuting

For electric scooters and bikes, we had to take a more direct approach to measuring the carbon emissions associated.

🛵 Electric Scooter

Figuring out the carbon footprint of electric scooters is a little difficult as most data evolves around shared dockless scooters. The actual ride on an electric scooter does not emit any carbon emissions, but the materials and manufacturing, the product transportation, and the charging does (source). The carbon footprint depends heavily on scooter longevity, and it is estimated that shared dockless scooters last for around six months, and emits around 202 grams of carbon emissions per mile. 5% of those 202 grams represent electricity for charging (whereas 43% of the 202 grams represent collecting and redistribution of the shared dockless scooters). The number we’ll be using for our calculation is therefore 10.1 gram/mile CO2e (202*0.05=10.1).

Sohee is the only one in the studio cool enough to ride around on an electric scooter, and she rides a Xiaomi m365 scooter. Sohee rode her scooter twice a day all year round, which means she rode 624 miles on her scooter in 2019. That results in Sohee emitting a total of 6.3 kg CO2 emissions on her electric scooter in 2019.

🚵‍♀️ Electric Bike

Joshie somehow owns more than one electric bike (hit him up for recommendations!), and Joshie rides one his electric bikes from Flatbush to Chinatown for 6.6 miles (and back again) for 5 months of the year, which results in 1,320 miles in 2019. Electric bikes have a lifecycle emissions rate of approximately 4.9 grams of CO2e per person miles (source), which means Joshie’s electric bike emitted 6.5 kg CO2 emissions in 2019.

Carbon emissions for Commuting Electricity in 2019 totals 12.8 kg CO2.

Business Travel (Ride Share, Van Rentals & Flights)

Business Travel includes ride shares, van rentals, and flights.

In 2019, Sanctu rented vans to go on our annual ski trip to Belleayre Mountain in Upstate NY, to Likeminds in Fishkill in Upstate NY, and to Philip Johnson’s Glass House in New Canaan, Connecticut. Hugh flew, solo or with one other coworker, to Nashville, San Francisco, and South East Asia a few to times for clients, and we also took the whole studio to ReactiveConf in Prague. Lastly, we also took some ride shares (though we mostly rely on subways).

Details on our van rentals, ride shares, and flights’ length, miles, and CO2 emissions can be found in our calculator under Scope 3.

🚌 Vans

For our social day or weekend trips, we usually rent two GMC Savana 15 passenger vans. It is estimated that a GMC Savana van emits 592 grams CO2 per mile, and we drove a total of 1,060 miles in vans. That totals 628 kg CO2 emissions in 2019.

Source: Fuel Economy

🚗 Car (Ride Shares)

A car emits around 404 grams CO2/ passenger mile. We are fully aware of the many variations of vehicle types, but as the majority of the car rides accounted for are from Uber, we’ll base our calculations on this number. Please see a note on Lyft versus Uber below.

Source: United States Environmental Protection Agency

We took 97 Uber rides in 2019 resulting in 679 miles. At 404 g CO2/ mile, the carbon emissions for ride sharing commuting in 2019 totals 274 kg CO2e.

👉 A note on our ride sharing trips

At Sanctuary, we use Lyft as our primary car service provider. Lyft is a great company in the sense that they offset all the carbon footprint their customers have emitted riding with Lyft drivers. As such, we have not included our Lyft miles and associated CO2 emissions in our total calculations as they’ve already been offset.

For any international travel, we use Uber (as Lyft is not as accessible abroad).

We’ve included our Uber miles in our total carbon footprint (under the “Business Travel” in Scope 3 in our calculator). This has been buffered as we haven’t adapted the carbon emissions to any shared Uber rides, and rides in hybrid or electric vehicles.

✈️ Flights

We’ve found substantial variance in given amount of CO2e per passenger mile for flights.

For instance, 108.86g CO2e per passenger mile (BlueSkyModel), 168.33g CO2e per passenger mile (CarbonIndependent), 221.66g CO2e without secondary effects per passenger mile for domestic flights (BBC, Gov.UK), and 170g CO2e without secondary effects per passenger mile for long haul flights (BBC, Gov.UK).

The numbers we will be using in here are for domestic flights 423.33g CO2e with secondary effects per passenger mile, and for long haul flights 325g CO2e with secondary effects per passenger mile (BBC, Gov.UK). We’ve decided to go with CO2e with secondary effects as these numbers are higher than any other we’ve found, and we want to ensure that our data is conservative.

Additionally, we’ve compared our manual calculations to results from online calculations, and our own calculations are a slightly higher, which we’re happy with as an additional buffer.

CO2e without secondary effects

Domestic flight: 221.66g = 1 mile (133g = 1 km)

Long haul flight: 170g = 1 mile (102g = 1 km)

CO2e with secondary effects

Domestic flight: 423.33g = 1 mile (254g = 1 km)

Long haul flight: 325g = 1 mile (195g = 1 km)

Source: BBC, Gov.UK

We calculated our flight miles (with layovers) with the Air Miles Calculator, and in 2019, Sanctu flew a total of 182,162 miles. This totals 60.7 metric tons of CO2 (or 60,667.77 kg), and is by far our biggest source of carbon emissions.

Office Materials, Team Meals, Snacks, Insurance & Activities

It is challenging manually estimating the carbon footprint of various office materials, team meals, snack purchases, insurance, activities, and hotel stays. In order to calculate our CO2 emissions within these categories, we’ve used this Carbon Footprint Calculator. We understand that this CO2 emissions result is a general calculation based on averages, and not fully accurate of our situation. If someone has a suggestion on a better approach, please reach out and let us know!

We collected our costs in the various categories from our Amazon and Instacart history and our accounting tool (QuickBooks), and categorized them in the calculator (see below). Our most harmful purchases were hotels, restaurants and bars, furniture for the studio, and telephone costs.

The total came to 15.38 metric tons CO2 emissions.

Source: Carbon Footprint

👉 What have we learnt, and how can we do better?

As for studio improvements (when we had one!), we made some smaller changes around the studio that are more aligned with our values, and the types of businesses we want to support. These include purchasing eco-friendly toilet paper and paper towels from PlantPaper, reusable cups from Stojo for our afternoon walks to get to-go coffee, and buying offsets from Project Wren for Sanctu’s employees’ birthdays.

Oh, and of course, fuck Amazon.

sohee fishing at likeminds (photo credit Meredith Jenks)

Our Total Carbon Footprint for 2019

Scope 1 (0%)


Scope 2 (38.98%)

Studio Electricity — 2,502.16 kg CO2e

Cloud Computing & Web Hosting — 11,263.29 kg CO2e

Data Transfer at the Edge — 36707.9812 kg CO2e

Total Scope 2 Emissions = 50,473.43 kg CO2e

Scope 3 (61.02%)

Laptops — 839.19 kg CO2e

Privately owned vehicles — 252.10 kg CO2e

Employee Commuting — 1,194 kg CO2e

Electricity for Commuting — 12.8 kg CO2e

Business Travel Vehicles — 902 kg CO2e

Business Travel Flights — 60,667 kg CO2e

Miscellaneous (Studio Materials, Meals, Hotels, Phone, and more) — 15,140.00 kg CO2e

Total Scope 3 Emissions = 79,007.48 kg CO2e

Backdating our Carbon Footprint to 2015

In order to backdate our carbon footprint to our time of founding (January 28th, 2015), we’ve decided to operate on an average carbon footprint per employee, per month, based on our 2019 emissions. While we’re not taking into account contractors who have come and went, this feels like an adequate approach, given 2019 easily had the most Business Travel & Web Hosting costs of any previous year, effectively meaning we’re over estimating that per-employee-month figure.

2015–2018: 192x Total Employee months

During 2019: 136x Total Employee Months

2019: 131,861.19 kg CO2e / 136 Employee Months

= 969.568 kg CO2e per Employee Month

2015–2018: 192 Employee Months * 969.568 kg CO2 per Employee Month

= 186,157.056 kg CO2e, 186.157 Metric Tons of CO2

Sanctuary Computer’s emissions from 2015–2018 are conservatively estimated as 186.157 metric tons of CO2e.

Carbon Offsetting our Prior Damage

The carbon credit market is a wild world. Between tree planting, machine drawdown, methane capture, carbon sequestration, wind & solar — it’s important to recognize that Carbon Offsets and RECs are not the same thing, and not all carbon products are created equal.

We’ve got a guide to navigating this weird world (and avoiding greenwashers) over here:

For 2019, we’ve chosen Carbon Sequestration as our primary offset instrument:

Carbon sequestration is name given to a process that stores carbon in the earth — we’re excited by the newly forming markets that connect farmers (practicing carbon rich farming methodologies) with carbon buyers.

We’ve decided to work with Nori (a platform that accredits carbon drawdown in a scientific fashion, and sells that sequestered carbon directly from farmers) and its verified partner Harborview Farms to offset 150% our of 2019 carbon emissions.

We’ve purchased 195 metric tons to ensure that we offset 150% of our 2019 carbon emissions, effectively making us carbon negative.

Nori charges $15 per metric ton of CO2e. As such, offsetting 150% of our 2019 cost us $2,925.00 (plus $438.75 in credit card fees)— please see below for proof of purchase:

And you can view that transaction on the Blockchain here.

For 2015–2018:

Working against Nori’s $15 per metric ton, we have allocated $4,188.53 to offset 150% of our carbon emissions date from 2015–2018. In order to spread our effect, we’ll be continuing to spend that budget over the next six months with projects we find compelling.

Please refer to our resources site for some of our favorite projects, and our reasoning behind why we back them:

You can follow us on Twitter, where we’ll be sharing those incremental purchases.

gettin it done

Our 2020 Sustainability Goals

Overall, we’re expecting our 2020 carbon footprint to be significantly lower than 2019 despite having more employees (welcome to the fam, XXIX!). This is in part due to the pandemic (less commuting, business travel, and snacks and meals as our office is currently in storage), and in part because we now have actionable data to make improvements!


  • Offering an innovators discount (10% off our standard pricing) for entrepreneurs working in sustainable farming, renewable energy, ocean cleanup, and other such industries.
  • Including sustainability in our rubric for taking on new clients, so that we can go into new client engagements after vetting their impact.
  • Helping founders introduce sustainability into their launch and marketing strategies.
  • Offering consultancy services in this space to clients and interested parties.
  • Offering to conduct LCA studies for clients with physical products.


  • Switching to using a 100% Green Host (Azure, Google Cloud, or an Equinix based provider).
  • Progressively offsetting our whole existence before the end of 2020.
  • Offering a bonus vacation day if an employee takes the train to and from their destination.
  • Breaking out book keeping categories for Secondary Carbon Footprint, to make that math easier in the future.

Let’s keep chatting!

This is all relative new to us, and we are by no means experts. We’re doing the best we can, and we will continue to be curious and learn as much as we can.

Please feel free to reach out if you’d like to chat more, or if you’d like help doing the same for your company! (isabel@sanctuary.computer & hugh@sanctuary.computer)


We haven’t made any corrections to the article or calculations yet, but if anyone finds misinformation or any miscalculations, please email us, and we’ll edit and list the corrections edits made here.

References & Resources:

Sanctuary Computer

Articles & Reports

Calculators & Tools

Companies We Like