day of observance.
For 2014, August 19th represents the day on which mankind has consumed a full year's worth of renewable, natural resources. That also means that, for the rest of the year, we'll be dipping into nature's resource reserves, "eating our seed corn" if you will. That ensures that Earth Overshoot Day, 2015 will fall well prior to August 19.
Just a few years ago Earth Overshoot Day fell in October, the ninth month. Now it's arriving in the seventh month. You can do the math and see where this is headed. Here's a chart tracing the advance of Earth Overshoot Day.
Overshoot impacts take several forms. Deforestation is one, desertification (the exhaustion of farmland and its transformation into barren desert) is another. The emptying of aquifers is a manifestation of overshoot. So too is the collapse of global fisheries through overfishing. Another form of overshoot is the accumulation of pollution and other contaminants in our air, soil and water which reflects that we're outpacing nature's capacity to clean our environment.
Here's another way to visualize overshoot in the context of the planet's maximum carrying capacity and our excess consumption. Overshoot causes carrying capacity to decline so that the ecological deficit steadily grows.