A data centre campus proposed for the green belt on London's eastern edge would produce more than a million tonnes of carbon dioxide a year, which the Guardian calculated as equivalent to the footprint of 27,000 flights from London to New York. The figure comes from the developer's own planning documents.
The scheme is the East Havering Data Centre Campus, proposed by Digital Reef at north Ockendon, east of Upminster and Cranham on the boundary between Havering and Thurrock. It covers 218 hectares of green belt and would hold fifteen warehouse-sized data halls within what the developer describes as an ecology park. Power would come from a 600 megawatt connection to the National Grid by way of the nearby Warley substation. If built it would be among the largest such campuses in Europe.
What the number does and does not tell you
Comparisons to flights are a common way to make emissions legible, and they are imprecise. A transatlantic flight's per-passenger footprint varies with aircraft, load factor and whether the calculation applies a multiplier for the extra warming effect of emissions released at altitude. Different reasonable methods give different answers, and the resulting flight count moves accordingly.
The underlying figure is the more useful one, and it is worth being clear about where it comes from: this is the developer's own disclosure in its environmental statement, not a campaigner's estimate. That cuts both ways. It is not an adversarial number, which makes it harder to dismiss. It also depends on assumptions about how the electricity supplying the site is generated, and Britain's grid is getting cleaner, so a figure calculated on today's generation mix will overstate emissions in later years if that trend holds.
Digital Reef has said that where on-site carbon targets cannot be met, the shortfall would be handled through a payment into the borough's carbon offset fund. Offsetting is contested on its own terms, and whether a cash contribution is an adequate answer to emissions of this scale is precisely what the planning process is meant to weigh.
Green belt, and who decides
The land is green belt, which in English planning law carries a strong presumption against development. The Campaign to Protect Rural England has said it is appalled by the scheme and described it as massive environmental damage. Local opposition has also focused on water: large data centres consume substantial volumes for cooling, and campaigners have raised abstraction from the River Mardyke.
Havering's cabinet has treated the project as a significant economic opportunity for the borough, which is the other half of the argument and not a trivial one. Havering is not a wealthy borough, and a project of this size brings construction work, business rates and a long-term ratepayer.
The route the scheme is taking matters as much as its contents. Rather than a conventional planning application, it is proceeding through a Local Development Order, a mechanism that allows a council to grant permission for a defined type of development in a defined area in advance. Consultation on the order ran earlier this year. An LDO is lawful and not unusual for employment sites, but it front-loads the decision and gives objectors a narrower target than a application-by-application process would.
The wider squeeze
This is one scheme, and the pressure behind it is general. UK data centre capacity is expanding quickly on the back of demand for AI computing, and the electricity implications are large enough that the National Grid has warned of a steep rise in demand from the sector over the coming decade.
The government has designated data centres as critical national infrastructure and has made it easier for large projects to be treated as nationally significant, which routes decisions to central government rather than local councils. East Havering is not taking that route, but the direction of policy is unmistakable, and it sets up a collision that will recur: national industrial strategy wants these buildings, national climate targets constrain what they may emit, and the land they want is often land that local plans protect.
Havering's decision will not settle any of that. It will, however, be an early and unusually well-documented test of how the three are weighed against each other.
