Estimates from various sources on the environmental impact of digital communication
| Source |
Estimate / Claim |
Notes & Context |
Pawprint Eco
|
~ 0.3 g CO鈧俥 for a short text email |
Based on Mike Berners-Lee's "How Bad Are Bananas?" — higher for attachments or longer messages |
Carbon Literacy
|
Spam email ~ 0.03 g; short email ~ 0.3 g; long email (10 min write + 3 min read) ~ 17 g |
Gives a breakdown by email type and length |
Greenly
|
Storing 1 GB of data ~ 0.1 kWh/year (鈫� ~ 0.04 kg CO鈧俥/year in U.S. grid) |
They estimate ~ 0.1 kWh/year per GB of storage; scale depends heavily on electricity mix |
Stanford Magazine
|
3 to 7 kWh per GB (transfer + storage) |
"Saving & storing 100 GB per year 鈫� ~0.2 ton CO鈧�" under U.S. electricity mix assumptions |
Shift / AgainstData
|
Spam ~ 0.03 g; text email ~ 0.3 g; email with large attachment up to ~ 50 g |
They cite typical ranges and caveats about attachments & recipients |
+1Biosphere Sustainable
|
Sending: 4–50 g; Storing: ~ 10 g/year |
Says storing an email (i.e. keeping it alive on servers) causes about 10 g CO鈧� annually |
Scientific study on data storage
|
~ 1.73 g CO鈧� per GB (minimum scenario) |
From "Exploring the sustainability challenges 鈥�" — this is for data storage more broadly, not just emails |
"Green Algorithms"
|
Framework for estimating carbon cost of computation |
Useful methodology, though not specific to email storage per se |
"Chasing Carbon"
|
Emphasises uncertainty in estimating carbon of computing |
Highlights that estimating is "elusive" and depends on many factors |
