Environmental Impact, Concept and Measurement of

Environments on Earth are always changing, and living systems evolve within them. For most of their history, human beings did the same. But in the last two centuries, humans have become the planet's dominant species, changing and impoverishing the environment for all life on Earth and even decimating humans' own cultural diversity. Contemporary cultural worldviews that have severed humans' ancient connections with the natural world, along with consumption and population growth, have deepened this impoverishment. Understanding, measuring, and managing human environmental impacts – the most important of which is the impoverishment of living systems – is the 21st century's greatest challenge.