The Ecological Footprint tracks humanity’s demands on the biosphere by comparing the renewable resources people are consuming against the Earth’s regenerative capacity, or biocapacity: the area of land actually available to produce renewable resources and absorb CO2 emissions. Both the Ecological Footprint and biocapacity are expressed in a common unit called a global hectare, in which one gha represents a biologically productive hectare with world average productivity. The Ecological Footprint shows a consistent trend of overconsumption (Figure 3). In 2008, the Earth’s total biocapacity was 12.0 billion gha, or 1.8 gha per person, while humanity’s Ecological Footprint was 18.2 billion gha, or 2.7 gha per person. The amount of forest land needed to sequester carbon emissions is the largest component of the Ecological Footprint (55 per cent). This discrepancy means that we are in an ecological overshoot situation: it is taking 1.5 years for the Earth to fully regenerate the renewable resources that people are using in a single year.