Most MPs are happy to sound off about the problems of climate change. But few are willing to alter their lifestyles to actually tackle it.
One Labour minister, however, has taken the warnings about carbon emissions literally, selling his conventional constituency home to build one of the greenest houses in Britain.
Alan Simpson has raised £200,000 to convert a derelict lace mill into a state-of-the-art energy-saving residence which produces its own electricity and stores and recycles "grey water" from baths, showers and gutters. The eco-house has its own generator, a miniature wind turbine, and a roof studded with solar panels.
The outside walls are rendered with recycled volcanic rock and insulated with crushed wood; the internal walls are made of recycled cardboard.
Because it is so energy efficient, the house produces 50 per cent more energy than it uses. When he moves in next month, the MP for Nottingham South will not have to pay monthly electricity bills, but will receive cash back. "The house is so efficient it feeds into the national grid," he said.
"Everyone is going to have to reduce their carbon footprint on the planet. I am hoping that my house will be part of a new approach to living.
"The real challenge would be to take what is happening in my home and make other affordable houses like it - and then the development of sustainable energy systems for whole cities."
The small industrial building, in Nottingham's historic Lace Market, was derelict when the MP for Nottingham South spotted it. Its only inhabitants for the past 40 years had been hundreds of pigeons. After months of adaptation, the Victorian mill has been transformed.
Its in-built ventilation is based on a Babylonian cooling system developed 4,000 years ago. And in a nod to the wattle and daub insulation methods of bygone days, the walls are lined with straw. Low-flush lavatories were imported from Italy, while hi-tech windows let ultra-violet light in but not out.
A "grey water" recycling unit ensures that no water is wasted, but cleans, stores and reuses it. Clothes will be washed in an energy-efficient washing machine with the contents of baths, gutters and showers. Even the washing-up water will be recycled while the potato peelings will be composted. The self-generating power shower requires no electricity at all.
The stair treads are recycled from old wood, the floor matting is composed of recycled materials, and glass panels on each floor mean that artificial light is needed only after dark. A wind turbine onthe side of the house will generate power while the solar-panelled roof constantly absorbs energy from the sun.
This week the finishing touches will be put to the tubular cardboard walls. But many of the lace mill's original features, including the Victorian brickwork and wood floors, have been retained during the conversion.
The Nottingham architect Julian Marsh, who designed the eco-residence in consultation with Mr Simpson, said the aim was to integrate "green technology and modern design".
"We have tried to reuse timber, we have reused all the brickwork and slates and we have worked with the shape of the existing building to create a clean, modern interior," he said.