pbr A new scheme to drive down carbon emissions from big businesses and organisations has gone live, amid concerns some companies are not clear on what they need to do to meet the requirements.br ppbr The Carbon Reduction Commitment (CRC) will require businesses, Government departments and public sector organisations such as hospitals which use more than around £500,000 a year of energy to buy "allowances" to cover their carbon emissions.br ppbr The scheme, which will require around 5,000 organisations in the UK to participate, will rate them in a league table on the efforts they are making to be more energy efficient - with the top businesses rewarded and the worst penalised.br ppbr Hilton Hotels, the National Theatre, London Fire Brigade and Guy's and St Thomas' NHS Foundation Trust are among the organisations which will fall under the CRC.br ppbr It is one of two schemes launched today to reduce emissions in the UK, alongside the "feed-in tariffs" initiative which will pay people a fixed amount for electricity they generate from small-scale renewable power such as solar panels or wind turbines.br ppbr But a survey of businesses by npower found almost half (49 per cent) do not understand what is required to buy carbon allowances, while 44 per cent believe the level of advice on the CRC has been inadequate.