Experts at the Global Footprint Network calculate that 19 December 1987 was the first time that humanity used up a year's allotment of the earth's resources before a year finished. Each year, this date is moving earlier. Today we pass the threshold of the planet's capacity, equalling a need for 1.3 planets to sustainably support our current consumption.

Global Footprint Network won the Skoll Award in 2007 for their work developing a metric to evaluate the impact of lifestyles around the world on the environment that supports us. The calculations used by Global Footprint are published in a detailed paper National Footprint and Biocapacity Accounts: The Underlying Calculation Method (http://www.footprintnetwork.org/download.php?id=5).

"Humanity is living off its ecological credit card," according to Dr. Mathis Wackernagel, Executive Director of Global Footprint Network. "Just as spending more money than you have in the bank leads to financial debt, ecological overshoot, or using more resources than the planet can renew in a year, accumulates an ecological debt. This can go on for a short time, but ultimately it leads to a build up of waste and the depletion of the very resources on which the human economy depends."

According to the Global Footprint Network: "One of the most significant consequences of our global overshoot is climate change, but collapsing fisheries, deforestation, and topsoil loss around the world are also indicative of our mounting ecological debt." To see more details and specific examples of the depletion of the planet by human activity, check out Ecological Debt Day.

(By Christine Lepisto, Tree Hugger, 06/10/2007)