Those eco-warriors at the Wales Office have managed to cut their carbon emissions by an impressive 85 per cent during the last decade.
It sounds dramatic, and is not due, apparently, to the fact that the department handed over all its executive powers to the Welsh Assembly in 1999.
My mole in Gwydyr House, its Whitehall home, tells me: "I've been told that because we are such a small office, little things that we can do to reduce our footprint have a disproportionate impact."
It's true that the Wales Office didn't even have a state-subsidised airline to cancel. Secretary of State Peter Hain has long-believed in a red-green agenda, although the impact of his rooftop solar panels is rather undermined by his preference for cooking on an Aga and a fondness for Formula1.
Perhaps junior Minister Wayne David got a warm hand-knitted sweater for Christmas that allowed him to turn down the office thermostat?
Possibly, although this photograph suggests Mr Hain got there first. The Wales Office says: "We've done two things: moved to the Whitehall Distribution System for our heating (a centralised heating system for buildings in Whitehall), and turned off the heating at weekends and other periods when the office was closed."
You may wonder why the building was heated while empty anyway, but I'm not bright enough to answer that one.