Apr 10, 2007 — A Vermont activist has sparked a national protest over global warming set for this Saturday, with more than 1300 events planned in all 50 states. Late last summer, environmentalist and writer Bill McKibben helped lead a five-day walk across Vermont to demand action on global warming. On Saturday, thousands are expected to take part in rallies to demand that Congress enact curbs on carbon emissions that would cut global warming pollution 80% by 2050. The campaign, organized by McKibben and some of his students at Middlebury College, has won widespread support from a wide variety of environmental, student, and religious groups. McKibben told Todd Moe that Saturday's event will be the largest grassroots environmental protest since Earth Day 1970.