To help counter these effects, in 2012 the various Chamonix-Mont Blanc authorities introduced a climate and energy action plan, committing the region to a 22% reduction in its greenhouse gas emissions by 2020. The plan included proposals to improve air quality by banning those lorries from using the Mont Blanc Tunnel which were deemed to be the most polluting and which, at times, had reduced air quality to levels more usually associated with the streets of Paris.