Seed Magazine: In 2000, as the green shoots of spring cracked through winter`s icy grip on the northern hemisphere, a letter from the Nobel laureate Paul Crutzen and his colleague Eugene Stoermer appeared in the news bulletin of the International Geosphere-Biosphere Programme. In it, Crutzen and Stoermer made the case that the Holocene, the geological epoch that had held sway on Earth for the past 12,000 years, was at an end. In its place, with a start date pegged to the late 18th century commercialization …