CRUNCH time for the Kyoto protocol is fast approaching. 2012 marks the end of the two-year period during which rich nations must prove that they have cut emissions from 1990 levels. That may be an impossible task.
The problem lies with error bars. in Laxenburg, Austria, has calculated that countries can only report their emissions to within 5 to 10 per cent of what they actually emitted (Climatic Change, DOI: ). This is because there is no direct way of measuring how much carbon dioxide, say, a country emits.
鈥淐ountries can only report their emissions at best to within 5 to 10 per cent of what they actually emitted鈥�
Advertisement
Instead, nations must estimate their emissions indirectly, by totting up the amount of coal and oil that was burned to power their industry and transport sectors, for instance. Each of these estimates necessarily comes with big uncertainties.
Yet the European Union, which promised the biggest cuts by 2012, must reduce its emissions by 8 per cent relative to 1990 levels. That鈥檚 less than the error bars, so it will be near impossible to say whether it, or any other nation, have met their commitments.
鈥淭he significant uncertainty in greenhouse gas emissions needs to be tackled,鈥� says of Royal Holloway, University of London, who coordinates the EU鈥檚 methane monitoring programme.
