I have heard arguments about Great Lakes pollution with regard to maintaining pipeline 5 across the Straits of Mackinac, but I have not heard any about the absolute necessity of cutting off the oil flow forever. Escalating climate change demands we keep fossil fuels in the ground — science tells us so. Piping dirty Canadian oil to refineries in the southern United States only prolongs our dependence on petroleum. It is time to stop pumping, piping and processing this dangerous product. The welfare of the planet demands it.