A joint proposal by the US, Canada, and Mexico seeks an 85 percent reduction in hydroflurocarbon use worldwide in an effort to uphold a declaration signed by more than 90 countries in November 2010. The North American proposal calls on developed countries to initiate the phaseout in 2015, leading to an 85 percent reduction below unspecified baseline levels by 2033. Developing countries would initiate their phaseout in 2017, leading to an 85 percent reduction by 2043.