Energy companies should be forced to insulate every empty loft and cavity wall in the UK within four years. That was the call this week from the independent Committee on Climate Change (CCC), which says the move would cut national carbon emissions.  In the UK, 10m lofts remain unlagged and 8m houses with cavity walls have yet to be insulated.  according to a CCC report, the number of professional installations of loft and cavity wall insulation fell by 30% between 2009 and 2010.  Friends of the Earth says: "Forcing energy companies to carry out all the necessary energy efficiency improvements is an attractive idea."