Carbon intensity of global electricity

World · 2025 · life cycle · Ember

Producing 1 kWh of electricity emits 458 gCO2e on average worldwide in 2025, over its life cycle, according to Ember.

This is the default value for the calculations of the hub, the blog and the AI Impact Database when it is not known where the servers run.

See the source

The Earth seen from space, "Blue Marble", 2002. NASA, Visible Earth, public domain

Definition and scope

Greenhouse gas emissions of one kilowatt-hour of electricity produced worldwide in 2025, in life cycle assessment, according to Ember: the same source for all the countries of the map and the database.

What is included

The CO2 emitted by power plants
The construction of power plants and the extraction of fuels (life cycle)
The other greenhouse gases, in CO2 equivalent

What is excluded

Grid losses and consumption: this is the electricity produced
Renewable electricity purchase contracts (market-based)

How the value is obtained

Value published by Ember and reused by Our World in Data, over the life cycle. The AI Impact Database uses it because it takes a single source for all countries; the hub and the blog read it in the database to convert electricity into CO2e when the country of the servers is not known, which is the case for the large assistants.

Limits and uncertainties

An average: the servers of an assistant often run on grids that are more or less carbon-intensive than the average.
Life cycle: the IEA, which counts the CO2 of power plants alone, gives 435 g; the two values cannot be compared without saying so.
Each edition has its own method: a value must not be placed in a series with that of another edition.

The order of magnitude

All figures

458 gCO2e/kWh on a carbon intensity scale, with another reference figure and 10 values from the linked chart, brought to the same unit. Each tick multiplies by 10.