Developers working for Google have significantly misstated how much carbon two proposed AI datacentres will contribute to the UK’s total emissions in planning documents reviewed by the Guardian.

The tech company wants to build two huge datacentres – one 52-hectare (130 acre) project in Thurrock and another at an airfield in North Weald, both in Essex. To do so, developers are required to submit planning documents calculating how much carbon these projects will emit as a proportion of the UK’s total carbon footprint.

In both cases, they appear to have compared one year of the proposed datacentre’s emissions with the UK’s entire five-year carbon budget, understating the significance of their emissions by a factor of five, according to experts at the tech justice nonprofit Foxglove.