Written question asked by Lord Avebury (Liberal Democrat), in the House of Lords. It was answered by Lord Rooker (Labour) on Thursday, 8 February 2007.

Single/Double Summer Time

Question: What assessment they have made of the estimate by University of Cambridge scientists, reported in Nature on 25 January, that moving the clocks forward to give an extra hour of daylight in the evening could save around £485 million per year and reduce carbon dioxide emissions by 170,000 tonnes.

Answer: The saving in carbon dioxide emissions reported in Nature is equivalent to about 0.03 per cent of UK carbon dioxide emissions in 2005. However, research undertaken in 2005 by the Building Research Establishment on behalf of Defra found that, while moving the clock forward one hour throughout the year to align the UK with Central European Time would realise some savings in carbon dioxide emissions from domestic lighting and non-domestic cooling, those savings would be more than offset by increases in non-domestic lighting and cooling. The BRE estimates do not take account of any additional savings from reductions in peak demand leading to greater electricity generating efficiency. We have not analysed the overall financial costs and benefits that could result from the change. Work by the Transport Research Laboratory, commissioned by the Department for Transport and published in 1998, suggested that there could be a net saving of over 400 people killed or seriously injured per year, although as the total number of road accident casualties has fallen significantly since 1998, any casualty reductions arising from the change are also likely to have fallen. All those estimates are subject to considerable uncertainty, as the Nature article points out. Any changes to the UK time-zone would need to take full account of the effect on society as a whole.

Secondary information