Pete Smith is very down to earth. Not least because he’s interested in soil and the vital role it plays in helping us to feed the world, mitigate climate change and maintain a rich diversity of species on planet earth. He was born in a pub and failed the 11+ exam (designed to identify bright children just like him) but he became a distinguished professor nonetheless. Tackling climate change in isolation is a mistake, he says. We need to consider all the challenges facing humanity and identify strategies that deliver benefits on all fronts: food security, bio-diversity and human development goals. He tells Jim Al-Khalili about his life and work and the urgent need for our degraded peat bogs to be restored. Peat bogs that have been drained (for grazing or to plant trees) add to our carbon emissions. Healthy peat bogs, however, are carbon sinks. Producer: Anna Buckley