A walk in the park - and so much more!

Antony Funnell: This week on Future Tense, some good news about the environment.Marc Hockings: The growth in protected areas over the last 50 or 60 years, has been spectacular, so we think that the first of what people would commonly recognise as protected areas (the Yellowstone National Park was declared only in the late 1800s) then we've seen an almost exponential growth in protected areas since that time, and it shows no sign of slowing down at this stage.