 Romer said that he was optimistic that measures will be taken in time to avert climate catastrophe.Romer compared the angst and lack of political will in imposing a carbon tax to the initial angst surrounding the chlorofluorocarbon (CFC) ban and the positive impact it had on restoring the depleted ozone layer.In giving the Nobel to Nordhaus and Romer, the Royal Swedish Academy of Sciences cited Nordhaus as saying "the most efficient remedy for problems caused by greenhouse gases is a global scheme of universally imposed carbon taxes".