EARTH OVERSHOOT DAY OF 2011 WAS ON SEPTEMBER 27
In 10 months, humanity has exhausted nature’s budget for the year.
Ecological Debt Day, also known as “Earth Overshoot Day”, is the calendar date in which the total resources consumed by humanity will exceed the capacity for the Earth to generate those resources that year. Each year it is calculated by dividing the world biocapacity, the number of natural resources generated by the earth that year, divided by the world Ecological Footprint, humanity’s consumption of the Earth’s natural resources for that year, and multiplied by 365, the number of days in one Gregorian calendar year; expressed as:
[worldbiocapacity / worldEcologicalFootprint] x 365 = EcologicalDebtDay
When viewed through an economic perspective, Ecological Debt Day/Earth Overshoot Day represents the day in which humanity enters deficit spending, scientifically termed “overshoot”. In recent years this issue has gained notoriety as it appears to represent a trend rather than a freak occurrence.
ECOLOGICAL FOOTPRINT
The ecological footprint is a measure of human demand on the Earth's ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet's ecological capacity to regenerate. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to mitigate associated waste. Using this assessment, it is possible to estimate how much of the Earth (or how many planet Earths) it would take to support humanity if everybody followed a given lifestyle.
For 2006, humanity's total ecological footprint was estimated at 1.4 planet Earths – in other words, humanity uses ecological services 1.4 times as fast as Earth can renew them. Every year, this number is recalculated — with a three year lag due to the time it takes for the UN to collect and publish all the underlying statistics.
If everyone lived the lifestyle of the average American we would need 5 planets.
Our current global situation is that since the 1970s, humanity has been in ecological overshoot with annual demand on resources exceeding what Earth can regenerate each year.
It now takes the Earth one year and six months to regenerate what we use in a year.
By measuring the Footprint of a population—an individual, city, business, nation, or all of humanity—we can assess our pressure on the planet, which helps us manage our ecological assets more wisely and take personal and collective action in support of a world where humanity lives within the Earth’s bounds.
Conceived in 1990 by Mathis Wackernagel and William Rees at the University of British Columbia, the Ecological Footprint is now in wide use by scientists, businesses, governments, agencies, individuals, and institutions working to monitor ecological resource use and advance sustainable development.
Today humanity uses the equivalent of 1.5 planets to provide the resources we use and absorb our waste. This means it now takes the Earth one year and six months to regenerate what we use in a year.
Moderate UN scenarios suggest that if current population and consumption trends continue, by the 2030s, we will need the equivalent of two Earths to support us. And of course, we only have one.
Turning resources into waste faster than waste can be turned back into resources puts us in global ecological overshoot, depleting the very resources on which human life and biodiversity depend.
The result is collapsing fisheries, diminishing forest cover, depletion of fresh water systems, and the build up of carbon dioxide emissions, which creates problems like global climate change. These are just a few of the most noticeable effects of overshoot.
Overshoot also contributes to resource conflicts and wars, mass migrations, famine, disease and other human tragedies—and tends to have a disproportionate impact on the poor, who cannot buy their way out of the problem by getting resources from somewhere else.
Individuals and institutions worldwide must begin to recognize ecological limits. We must begin to make ecological limits central to our decision-making and use human ingenuity to find new ways to live, within the Earth’s bounds.
This means investing in technology and infrastructure that will allow us to operate in a resource-constrained world. It means taking individual action, and creating the public demand for businesses and policy makers to participate.
Earth Overshoot Day (based on a concept devised by UK-based new economics foundation), helps conceptualize the degree to which we are over-budget in our use of nature. While meant as an estimate more than an exact date, Earth Overshoot Day helps conceptualize the size of the gap between a sustainable level of ecological demand and how much is currently required to support human activities globally. Of course, we only have one Earth.
The fact that we are using (or “spending” natural capital) faster than it can replenish is similar to having expenditures that continually exceed income.
In planetary terms, the results of our ecological overspending are becoming more clear by the day. Climate change – a result of carbon being emitted faster than it can be reabsorbed by the forests and seas – is the most obvious and arguably pressing result. But there are others as well: shrinking forests, species loss, fisheries collapse and freshwater stress to name a few. The environmental crises we are experiencing are all symptoms of an overall trend—humanity is simply using more than the planet can provide.
Next chapter: Our Human Development Initiative
Sustainable human development will occur when all humans can have fulfilling lives without degrading the planet. This, we believe, is the ultimate goal. Two leading indicators have identified how we can get there.
