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August 20 is Earth Overshoot Day !

August 20, 2013, 12:01 AM Geneva, Switzerland August 20 is Earth Overshoot Day, the approximate date humanity’s annual demand on nature exceeds what Earth can renew in a year. In just 7 months and 20 days, we have demanded a level of ecological resources and services — from food and raw materials to sequestering carbon dioxide from fossil fuel emissions — equivalent to what Earth can regenerate for all of 2013.

Humanity has exhausted nature’s budget for the year.

For the rest of the year, we are operating in overshoot. We will maintain our ecological deficit by depleting stocks of fish, trees and other resources, and accumulating waste such as carbon dioxide in the atmosphere and oceans. As our level of consumption, or “spending,” grows, the interest we are paying on this mounting ecological debt — shrinking forests, biodiversity loss, fisheries collapse, food shortages, degraded land productivity and the build-up of carbon dioxide in our atmosphere and oceans — not only burdens the environment but also undermines our economies. Climate change — a result of greenhouse gases being emitted faster than they can be absorbed by forests and oceans — is the most widespread impact of ecological overspending.

In 1961, humanity used only about two-thirds of Earth’s available ecological resources. Back then, most countries had ecological reserves. Yet both global demand and population are increasing. In the early 1970s, increased carbon emissions and human demand for resources began outstripping what the planet could renewably produce.

We went into ecological overshoot.

In 8 Months, Humanity Exhausts Earth's Budget for the Year

Just as a bank statement tracks income against expenditures, Global Footprint Network measures humanity’s demand for and supply of natural resources and ecological services. And the data is sobering. Global Footprint Network estimates that in approximately eight months, we demand more renewable resources and C02 sequestration than what the planet can provide for an entire year.

In 1993, Earth Overshoot Day—the approximate date our resource consumption for a given year exceeds the planet’s ability to replenish—fell on October 21. In 2003, Overshoot Day was on September 22. Given current trends in consumption, one thing is clear: Earth Overshoot Day arrives a few days earlier each year.

Earth Overshoot Day, a concept originally developed by Global Footprint Network partner and U.K. think tank new economics foundation, is the annual marker of when we begin living beyond our means in a given year. While only a rough estimate of time and resource trends, Earth Overshoot Day is as close as science can be to measuring the gap between our demand for ecological resources and services, and how much the planet can provide.

The Cost of Ecological Overspending

Throughout most of history, humanity has used nature’s resources to build cities and roads, to provide food and create products, and to absorb our carbon dioxide at a rate that was well within Earth’s budget. But in the mid-1970s, we crossed a critical threshold: Human consumption began outstripping what the planet could reproduce.

According to Global Footprint Network’s calculations, our demand for renewable ecological resources and the services they provide is now equivalent to that of more than 1.5 Earths. The data shows us on track to require the resources of two planets well before mid-century.

The fact that we are using, or “spending,” our natural capital faster than it can replenish is similar to having expenditures that continuously exceed income. In planetary terms, the costs of our ecological overspending are becoming more evident by the day. Climate change—a result of greenhouse gases being emitted faster than they can be absorbed by forests and oceans—is the most obvious and arguably pressing result. But there are others—shrinking forests, species loss, fisheries collapse, higher commodity prices and civil unrest, to name a few. The environmental and economic crises we are experiencing are symptoms of looming catastrophe. Humanity is simply using more than what the planet can provide.

Methodology and Projections

In 2011, Earth Overshoot Day came a few weeks later than it did in 2010. Does this mean we reduced global overshoot? The answer, unfortunately, is no.

Earth Overshoot Day is an estimate, not an exact date. It’s not possible to determine with 100 percent accuracy the day we bust our ecological budget. Adjustments of the date that we go into overshoot are due to revised calculations, not ecological advances on the part of humanity. Based on current assumptions, Global Footprint Network data now suggests that since 2001, Earth Overshoot Day has been moving three days earlier each year.

As Global Footprint Network methodology changes, projections will continue to shift. But every scientific model used to account for human demand and nature’s supply shows a consistent trend: We are well over budget, and that debt is compounding. It is an ecological debt, and the interest we are paying on that mounting debt—food shortages, soil erosion, and the build-up of CO₂ in our atmosphere—comes with devastating human and monetary costs.


Click here for the 2013 press release.

Click here to learn more about Earth Overshoot Day, and how it has changed over time.