Ecosystems

Even under the most optimistic scenarios of coordinated global action to cut climate pollution, we face an era of rapid and accelerating climate change. Dams and other river infrastructure projects have been, and in most cases still are, designed based on the now obsolete assumption that future river flow patterns will be like those of the past.

The recently released Millennium Ecosystem Assessment, a UN–sponsored analysis of the overall health of the planet, reveals the extent to which humanity’s destruction of the natural world is threatening our ability to thrive on the planet. The report – the largest–ever assessment of environmental changes and their impacts on human well–being – reveals the rapid and accelerating degradation to ecosystems that are essential to life on Earth.

Land and water are ecologically linked in a natural system called a watershed. From the smallest droplet to the mightiest river, water works to shape the land, taking with it sediment and dissolved materials that drain to watercourses and, in most cases, eventually to the sea.