Ecological Footprint

The Ecological Footprint is a measure of human demand on the Earth’s ecosystems. It compares human demand with planet Earth’s ecological capacity to regenerate. It represents the amount of biologically productive land and sea area needed to regenerate the resources a human population consumes and to absorb and render harmless the corresponding waste. Using this assessment, it is possible to estimate how much of the Earth (or how many planet Earths) it would take to support humanity if everybody lived a given lifestyle.
Wikipedia

Globally, people are using about 25% more natural resources than the planet can replace. In the UK, we’re consuming three times our fair share of the planet’s natural resources.
World Wildlife Fund

In other words, if the whole world used resources at the same rate as the UK we would need three planets to sustain our way of life!

In reality we have only one planet and it’s a living one. We must all make it our business to keep it that way.