Flux continu

Over the past 50 years, humans have extracted the Earth’s groundwater stocks at a steep rate, largely to fuel global agro-economic development. Given society’s growing reliance on groundwater, we explore ‘peak water limits’ to investigate whether, when and where humanity might reach peak groundwater extraction. Using an integrated global model of the coupled human–Earth system, we simulate groundwater withdrawals across 235 water basins under 900 future scenarios of global change over the twenty-first century. Here we find that global non-renewable groundwater withdrawals exhibit a distinct peak-and-decline signature, comparable to historical observations of other depletable resources (for example, minerals), in nearly all (98%) scenarios, peaking on average at 625 km3 yr−1 around mid-century, followed by a decline through 2100. The peak and decline occur in about one-third (82) of basins, including 21 that may have already peaked, exposing about half (44%) of the global population to groundwater stress. Most

Freshwater is a fundamental resource in our world, even more than crude oil. Without freshwater, it would be impossible to maintain the current agricultural production that manages to feed nearly 8 billion human beings. Most of the world's agriculture, nowadays, is based on irrigation. It means that production depends on water that has been stored somewhere, naturally or artificially. And once you start depending on a limited stock of resources, you face a problem. Even renewable, if you exploit it faster than it renews itself, you will eventually run out of it. It is the phenomenon called "overexploitation"