Section 2.1: What is sustainability?
Section 2.2: Connections between humans & the natural environment
Section 2.3: Earth and its limits
Section 2.4: Major global (un)sustainability trends
2.4.3 Species extinction and biodiversity loss
2.4.5 Decline of natural resources
Section 2.5: Climate change – the facts
Section 2.6: Welcome to the Anthropocene – It’s all about humans
Water is a renewable resource that sustains life on earth and provides vital services to humans. About 70% of the earth surface is covered by water of which less than 3% is freshwater, making it a very scarce resource. About two thirds of this freshwater is inaccessible, locked away in glaciers, ice, and snow.
The exponential growth in human population since the 1800s has intensified competition for freshwater. For many of us, access to freshwater comes easily, and we do not consider it being a scarce resource. However, about 1.1 billion people globally lack ready access to freshwater, and 2.7 billion people experience water stress at least one month a year. The stark reality of such a water shortage is highlighted in this article: “Zimbabwe water shortage”
Water conflict is now a reality and is the root of many political tensions and development disputes. You can explore the interactive map on this website (http://worldwater.org/water-conflict/) to see just how often such conflicts occur.
The current rates of inefficient global water consumption is estimated to cause water shortages to two-thirds of the world population within the next 10 years.

Supplementary Resources
United Nations Environmental Programme – Supporting the Sustainable Development Goals and water
World Water Council “Water Crisis”
2015 Guardian Article “Why fresh water will cause the next global crisis”