Earth Overshoot Day marks the day in a given year when humanity’s demand for ecological resources and services exceeds the Earth's ability to regenerate and supply them. Earth Overshoot Day is organized and reported by the Global Footprint Network, a non-profit international think tank.

Since the early 1970s, demand for ecosystems has continued to outstrip supply. To determine Earth Overshoot Day each year, Global Footprint Network calculates the number of days that the Earth's biocapacity, the amount of ecological resources it can produce each year, will meet humanity’s ecological footprint. The remaining days are considered “overshoots”, when demand exceeds supply.

In 2020, policies such as the lockdown for COVID-19 pandemic containment caused a temporary drop in carbon dioxide emissions, which by the end of the year were reported to be 5.8% lower than 2019 emissions. Meanwhile, recent estimates show that carbon footprint in 2021 is expected to rise by 6.6 percent. On the other hand, the environmental carrying capacity of the world's forests in 2020 was estimated to have decreased by 0.5% due to deforestation and forest degradation, estimated at 1.1 million hectares in Brazil alone. The Global Footprint Network assessed the changes in greenhouse gas emissions and forest carrying capacity from January 1, 2021, and concluded that the global environmental footprint would be 4.6% higher than in 2020.

In response, Earth Overshoot Day in 2021 has been moved back to 2019 levels, to July 29, three months earlier than last year's August 22 in 2020. It is also estimated that as of 2020, humans will be consuming the equivalent of 1.7 Earths worth of resources in 2021, where it was estimated that we were exploiting the equivalent of 1.6 Earths.

A recent study involving NASA reported that the ability of tropical forests, also known as “the lungs of the world”, to absorb greenhouse gases is weakening due to deforestation and degradation. The biggest cause of deforestation is said to be the change in land use due to agriculture. The current state of agriculture has exceeded the limits of the earth's ecological carrying capacity, and it has been pointed out that one of the causes of this is the "externalization" of social costs such as environmental and health hazards associated with food. In other words, behind the current food gluttony that is causing Earth Overshoot is the fact that the price we pay for food does not reflect the cost of health and environment. Conversely, for much of the world, healthy food is too expensive to afford.

In 2021, the United Nations Food Systems Summit and other international events are planned to discuss the sustainable food system, and this is an opportunity to review the food we enjoy in relation to the global environment, climate change and health.

Contributor: IIYAMA Miyuki (Director, Information Program)