of UK think tankNew Economics Foundation originally developed the concept of Earth Overshoot Day. Global Footprint Network, a partner organization of New Economics Foundation, launches a campaign every year for EOD to raise awareness of Earth's limited resources. Global Footprint Network measures humanity's demand for and supply of natural resources and ecological services. Global Footprint Network estimates that in less than eight months, we demand more renewable resources and CO2 sequestration than what the planet can provide for an entire year. According to Global Footprint Network, throughout most of history, humanity has used nature's resources to build cities and roads, to provide food and create products, and to release carbon dioxide at a rate that was well within Earth's budget. But by the early 1970s, that critical threshold had been crossed: Human consumption began outstripping what the planet could reproduce. According to their model, our demand for resources 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-21st century. They state that the costs of resource depletion are becoming more evident. Climate change — a result of greenhouse gases being emitted — is the most obvious result and widespread effects. Other cited effects include: deforestation, species loss, fisheries collapse, monetary inflation and civil unrest. Global Footprint Network maintains that the ecological footprint model illustrates the gap between human demand and regeneration. According to them, demand is now exceeding what the planet renews. They admit that the accounting can be improved, and more details added, believing that in its current applications to countries the accounts typically underestimate human demand as not all aspects are measured. They also claim to overestimate biocapacity because it is ambiguous to determine how much of current yields are enabled by reduced future yield. Mathis Wackernagel, founder and president of the Global Footprint Network, states that depletion of crop land could be included in the Ecological Footprint accounts informing EOD, but that would "require data sets that do not exist within the UN data set". Thus, they claim ecological footprint accounts are metrics that merely define minimal conditions for sustainability, and that humans are likely worse for the planet than their model predicts.
Criticism
The Breakthrough Institute regards the idea of Earth Overshoot Day and how many earths we consume as "a nice publicity stunt". According to United Nations data, forests and fisheries are, as a whole, regenerating faster than they are depleted, while cropland and pasture use is equal to what is available. Hence, EOD does a poor job at measuring water and land mismanagement and only highlights the excess of carbon dioxide that humanity releases above what the ecosystem can absorb. In other words, the additional equivalent number of Earths that humanity requires is equivalent to a land area that, if filled with carbon sinks like forests, would balance carbon dioxide emissions.
