By Kirk Miller The sustainability think tank Global Footprint Network has marked July 28 as Earth Overshoot Day, the day when “humanity has exhausted Earth’s budget for the year.” And by budget, they mean the biological resources that the planet can regenerate during the entire year. “For the rest of the year, we are maintaining our ecological deficit by drawing down local resource stocks and accumulating carbon dioxide in the atmosphere,” they write. “We are operating in overshoot.” When measured in 1971, this day would have arrived in late December. July 28 is the soonest this overshoot esti…