CanWest News Service: The Canadian Football League announced plans in November to make the Grey Cup a "carbon neutral" event. The following month, Aeroplan unveiled a venture that would allow its members to neutralize the environmental impact of their jetliner travel. And when Hollywood attends the Oscars next month, the awards show will declare its presenters have a carbon footprint of zero. In each case, the move toward environmentalism is largely accomplished by the purchasing of "carbon …