The carbon footprint of streaming, email, and AI — smaller than you've heard

Few footprint topics attract more bad numbers than digital ones. A viral 2020 claim put an hour of Netflix at 1.6 kg of CO₂; the real figure, after the IEA and Carbon Brief corrected the math, is closer to 36–55 grams — roughly 30 times lower. Digital footprints are real, but the honest version is much smaller than the scary version.

Sourced per-use numbers

Rough, order-of-magnitude figures (they vary with device, network, and grid):

• An hour of streaming video: ~36–55 g CO₂ on average — about the same as boiling a kettle a few times. Watching on a phone over Wi-Fi is far lower than a big TV; the screen is usually the biggest part, not the data.
• An email: ~0.3–4 g, depending on attachments. The famous “send fewer emails” advice saves grams.
• A single AI chatbot query: very roughly 2–5 g on current estimates — small per query, though it adds up at billions of queries and is rising as models grow.
• A year of typical home internet + streaming: tens of kilograms — real, but a rounding error next to a single flight.

Where the real concern is

The per-use numbers are small, but two things deserve genuine attention:

1. Data-centre growth. Data centres are roughly 1–1.5% of global electricity today, and AI is pushing that up quickly. (Crypto mining is a separate, country-scale draw — see Bitcoin’s footprint.) The systemic question — how fast that electricity decarbonises — matters far more than whether you send one less email.
2. Hardware, not data. Manufacturing the phone, laptop, or TV usually dwarfs the energy of using it. Keeping a device two years longer beats almost any usage tweak.

The honest framing

Turning off autoplay won’t save the climate, and “digital detox for the planet” mostly isn’t where the tonnes are. Your streaming year is measured in kilograms; your flights, car, and home heating are measured in tonnes. The useful digital move is buy less hardware and keep it longer — the using is cheap, the making is not. For everything else, the big four categories are where attention pays off.

Sources: International Energy Agency, “The carbon footprint of streaming video: fact-checking the headlines”; Carbon Brief analysis of streaming estimates; IEA data-centre electricity estimates.