This is the concept behind Earth Overshoot Day, the day that international sustainability think-tank The Global Footprint Network calculates we’ve used up all the resources our ecosystem can replenish within a 12-month period. In order to come up with this number, the planet’s biocapacity (in global hectares) is divided by humanity’s ecological footprint, or demand on the ecosystem, for 2017. The ratio is then multiplied by 365 to come up with the calendar day we go into debt.
Related: 9 Little Things You Can Do To Fight Climate Change Every Single Day
The most important element of the equation is biocapacity: all biologically productive land and water that can regenerate resources and absorb human waste—an area that’s shrinking every year. Of course, the measure of biocapacity, which is based on data from the United Nations and other scientific research, can only be approximated. Earth Overshoot Day is a close estimate, not an exact calendar date, that is meant to increase awareness of a fast-approaching ecological collapse if we don’t start living within our means. For 2017, we hit our calculated overshoot by August 2.
Here's what you need to know about Earth Overshoot Day—and how we can get out of debt.
1. We’ve been in global overshoot since the 1970s. And it’s just getting bigger and bigger—like the national debt, except way more serious.
2. If we keep eating up resources at our current rate, the Global Footprint Network predicts it will take the equivalent of two planets to support us by 2030—doubling our earth debt.
3. Fifteen years ago, Earth Overshoot Day was in early October. It has been getting steadily earlier every year.
4. You can calculate your personal carbon footprint, and see how many planet Earths would be needed to sustain all of humanity if everyone had the same lifestyle as you.
Each year, more than 2 million people check their personal carbon footprint with this tool. Just try not to cry at the results—let them motivate you to make some small changes, instead.
5. But it's not all bad news! Here's a few things that you can do right now to help.
The Global Footprint Network has launched a campaign to work together to #movethedate of Earth Overshoot Day. There's a new pledge launched each week, and you can take one on as it fits your lifestyle. Every little bit helps, and these are little things you can easily take on to help the planet. You can see all of the #movethedate pledges here, and sign up for the one that fits you. Some of the easy pledges you can take on:
+ Try a new vegetarian recipe. We've got tons of delicious (and easy) ones for you to try.
+ Bike to work or to visit friends. Here's an easy guide to getting started, from a cycling professional.
+ Tackle your food waste. Here are 18 food scraps you're throwing away that you can actually eat.
Remember, even the smallest efforts can give us a start in getting out of debt, and there's no better time to begin than today.