It is the variety of life on Earth, in all its forms and all its interactions.
If that sounds bewilderingly broad, that’s because it is.
Biodiversity is the most complex feature of our planet and it is the most vital. “Without biodiversity,
there is no future for humanity,” says Prof David Macdonald, at Oxford University.
The term was coined in 1985 – a contraction of “biological diversity” –
but the huge global biodiversity losses now becoming apparent represent a crisis equalling – or quite possibly surpassing – climate change.
More formally, biodiversity is comprised of several levels, starting with genes, then individual species,
then communities of creatures and finally entire ecosystems, such as forests or coral reefs, where life interplays with the physical environment.
These myriad interactions have made Earth habitable for billions of years.
A more philosophical way of viewing biodiversity is this:
it represents the knowledge learned by evolving species over millions of years about how to survive through the vastly varying environmental conditions Earth has experienced.
Seen like that, experts warn, humanity is currently “burning the library of life”.