The human ecological footprint has outgrown itself, according to a report by the United Nations Environment Programme (UNEP). The 550-page report was five years in the making. It details how the human ecological footprint is 21.9 hectares (or 54.11 acres) per person, whereas the Earth’s biological capacity is only 15.7 hectares (or 38.79 acres) per person.
The report describes how 1.8 billion people will suffer from water scarcity by 2025; how modern agriculture is exploiting the land more intensively, planting more crops on the same amount of land, resulting in its degradation; and how more than 2 million people die each year due to indoor and outdoor air pollution.
Neville Ash of the UNEP World Conservation Monitoring Centre told New Scientist magazine that population growth—we’re now at 6.7 billion people and estimated to grow to 8 or 10 billion by 2050—is a large part of the problem. However, he says the main culprit is unsustainable consumption. The report’s authors say energy efficiency is the key to sustainability.