asked Her Majesty's Government:

Whether they can demonstrate with proven statistics that the current use of Greenwich Mean Time and British Summer Time produces better conditions in winter for athletes in training and for the reduction of obesity in children than would the lighter afternoons and evenings which would be created by single/double summer time. [HL972]

The Government are not aware of any proven statistics which show that the use of Greenwich Mean Time plus one hour produces better conditions in winter for athletes in training and for the reduction of childhood obesity than by a move to single/double summer time.

However, changing to single/double summer time would create lighter evenings throughout the year and increase the opportunities for outdoor sport and recreation.

asked Her Majesty's Government:

Whether they can demonstrate with proven statistics from the national grid that the current use of Greenwich Mean Time and British Summer Time during the winter months generates less carbon emissions than would be generated if the country switched to the lighter afternoons and evenings regime of single/double summer time. [HL973]

Work undertaken by the Building Research Establishment for Defra indicates that putting clocks in the UK forward an additional one hour in winter and summer (ie summer time in winter and double summer time in summer to match Central European Time) would lead to a net increase in carbon dioxide emissions corresponding to around 1 per cent of total UK emissions of carbon dioxide, as a result of increased energy consumption in UK buildings for lighting, space heating and cooling. The study also shows that a switch to British Summer Time all the year round would increase emissions by just under 0.5 per cent. The study was based on modelling patterns of energy use in the UK building stock. The Government have not commissioned any study on this subject based on national grid statistics.