What is Biodiversity?

For National Biodiversity Day, many organisations have posted on-line features and films about what biodiversity is and what it means for humankind and the planet. They are much better at defining the problems and solutions than I am. The Natural History Museum in London, for example, produced the following simple explanation and video. At a time when the natural world around us is clearly and rapidly changing, I think it important to notice what is happening right here, right now, and consider the ways in which we can take responsibility for promoting biodiversity on our own doorstep, even if the means available to us as individuals may seem to be small and insignificant considering the enormity of the problem.

What is biodiversity?