Earth Overshoot Day Guess-the-Date Contest

Earth Overshoot Day is the date when we have used more from nature than the planet can replenish this year. Can you guess the date for 2021? HINT: pandemic-related lockdowns, borders’ shutdowns, travel restrictions, curfews, and the like, which have been implemented around the world for the past 12 months, are still having an impact on humanity’s Ecological Footprint in 2021.

Explore the open data platform and use other information available on this website (hints here and there) to calculate your best estimate for Earth Overshoot Day 2021. You may find this page on how we calculated the date of Earth Overshoot Day 2020 useful also.

Our hope is that participants gain a better understanding of what Earth Overshoot Day is all about. And we want them to learn why solutions to #MoveTheDate are crucial to achieving sustainability, as defined by humanity’s ability to live within the means of our one planet. To help you with this activity, we have created a Lesson Plan, ideal for grades 6-8, but adaptable for other grade levels.

May 22, 2021 (International Day for Biological Diversity) is the deadline to submit your calculation methodology and result below.

The winner, as well as the date of Earth Overshoot Day 2021, will be announced on June 5.

  • Accepted file types: xls, xlsx, doc, docx, pdf.
What can you learn from the 2020 winning contest entry?

Hear from Keegan, William, Ronak and Rohan, and their math and science teachers, about their Guess-the-Date Contest experience in 2019.

“Earth Overshoot Day is a great opportunity to run some algebra and learn about what that hard-stop date means.”

Everybody knows that taking anything faster than it is being put back doesn’t work, argues Jaimie Cloud, the founder and president of the Cloud Institute for Sustainability Education in New York City. Although obvious with regard to personal finances, this equation is not on most people’s minds when it comes to managing our natural capital. So everyone needs to learn how to do the math, she adds. Watch her full interview with Laurel Hanscom, Global Footprint Network CEO, recorded on the eve of Earth Overshoot Day 2018.