The world is “walking blindly down a dangerous path,” warned UN Secretary-General António Guterres. “Unsustainable water use, pollution and uncontrolled global warming are sucking away mankind’s livelihood drop by drop.”

The report came just ahead of the three-day UN water conference that begins Wednesday. Around 6,500 participants are expected to attend, including 20 heads of state and government, dozens of ministers and hundreds of representatives from business and civil society. Germany is represented by Federal Environment Minister Steffi Lemke (Greens). Guterres wants the summit to develop an ambitious program with concrete proposals for action.

So far there is no international treaty on the subject and no UN water organization. The last water conference of a similar size was held in Argentina in 1997.