The variety of life on Earth is immense. Over 10 million species are thought to share our planet.
This range of living things is called biodiversity. It means the number of different species, and also the variation within species.
High biodiversity is important for healthy ecosystems.
Number of different species
Variety within species
Vital for healthy sustainable ecosystems
Each species performs a different role, and the variety of species helps buffer against change.
But global biodiversity is decreasing rapidly.
Global biodiversity is falling
Estimated reduction of 50 - 75% by 2100
And this could affect our own survival, because biodiversity is vital in a number of ways.
Firstly, all our food, many medicines, and materials come from living things.
Reducing diversity will threaten our future resources.
Secondly, loss of species affects the other life-support services they provide.
Different species pollinate plants, filter and purify water, restore soil, protect land from erosion, and cleanse the atmosphere.
Reducing biodiversity threatens the health of ecosystems, and so the whole environment.
Professor Emeritus E.O. Wilson, Harvard University - "We need every species. We need a great diversity of species. We need every species because when you start decreasing the numbers of species, you start reducing the stability of the area."
Because all living things are so interdependent, loss of biodiversity can undermine whole ecosystems.
So we need to conserve biodiversity, for our own survival.
And many believe we have a moral responsibility - of stewardship - to protect the diversity of life on Earth.