To the Editor:April 22 marks the 50th observance of Earth Day. Each of us can celebrate by reducing our driving, use of electric energy, and consumption of animals. That’s right!Last fall Oxford University's prestigious Food Climate Research Network and Germany's Heinrich Bolle Foundation concluded that solving the global warming catastrophe requires a massive shift to a plant-based diet. A 2010 United Nations report blamed animal agriculture for 70 percent of global freshwater use, 38 percent of land use, and 19 percent of greenhouse gas emissions. Carbon dioxide is emitted by burning forests to create animal pastures and by operating farm machinery to grow animal feed. The more damaging methane and nitrous oxide are released from digestive tracts of cattle and from animal waste cesspools, respectively.Moreover, meat and dairy production dumps more animal waste, crop debris, fertilizers, pesticides, and other pollutants into our waterways than all other human activities combined. It is the driving force behind wildlife habitat destruction.In an environmentally sustainable world, meat and dairy products in our diet must be replaced by vegetables, fruits, and grains, just as fossil fuels are replaced by wind, solar, and other pollution-free energy sources. Let's celebrate the 50th observance of Earth Day at our supermarket. Montana PendergrassMilford, Pa.