Hydroflurocarbons (HFCs) were initially developed to help cure the hole in the Ozone layer by replacing other gases that were causing the problem.
But the new chemicals have an unwanted side effect: they are powerful greenhouse gases, some have thousands of times more warming potential than carbon dioxide.
Greenpeace estimate that the amount of HFC in a typical domestic fridge is the carbon equivalent of driving a medium sized car from London to Moscow. While they only account for 2% of all greenhouse gases at present, HFCs are set to grow rapidly making up 20% by 2050.