How would you feel about a world where the seas were almost empty, the skies silent of wildlife, and there weren't even enough bugs to pollinate our crops? That's a vision of Britain predicted by some if our rich mixture of wildlife continues to shrink - from butterflies and bumblebees to skylarks and red squirrels. So far in 2010 the UK has missed two international targets aimed at halting the decline in some of our best-loved native species. As Panorama finds, there's more at stake than simply protecting the beauty of nature - the future of our food supply could be under threat.