In 2015, Earth Overshoot Day fell on August 13. However, every year Global Footprint Network improves its methodology and updates data to release a new edition of its National Footprint Accounts, which are used to calculate Earth Overshoot Day. Consequently, it is inaccurate to simply look at media accounts from previous years to determine past Earth Overshoot Days. Instead, a true apples-to-apples comparison of Earth Overshoot Days can only be made within the same edition of the National Footprint Accounts. Consistent time trends for the world and most nations are shown here.
The 2016 edition of the National Footprint Accounts includes 21 improvements over the 2015 edition, including some better data points. The most influential change involves improvement in carbon Footprint accounting.
The dates of past Earth Overshoot Days, as calculated with the National Footprint Accounts 2016 Edition, are: