Speculation and warnings of catastrophic climate change are not unprecedented. In 2001 the ''Guardian'' noted that some 70s headlines shouted, "Brace yourself for another ice age". In 1971 the journal ''Science'' reported that the subsequent cooling effect resulting from a possible eightfold increased from atmospheric aerosol concentrations, "if sustained over a period of several years - is believed to be sufficient to trigger an ice age." <ref>Reported by Alison George in ''Breaking the ice'', The Guardian, Thursday 28 June 2001</ref> | Speculation and warnings of catastrophic climate change are not unprecedented. In 2001 the ''Guardian'' noted that some 70s headlines shouted, "Brace yourself for another ice age". In 1971 the journal ''Science'' reported that the subsequent cooling effect resulting from a possible eightfold increased from atmospheric aerosol concentrations, "if sustained over a period of several years - is believed to be sufficient to trigger an ice age." <ref>Reported by Alison George in ''Breaking the ice'', The Guardian, Thursday 28 June 2001</ref> |