David Beerling is a Royal Society University Research Fellow and Honorary Reader in the Department of Animal and Plant Sciences at the University of Sheffield. He is holder of a 2001 Philip Leverhulme Prize for his work in the earth sciences. Ian Woodward is Professor of Plant Ecology in the Department of Animal and Plant Sciences at the University of Sheffield. He is author of Climate and Plant Distribution (1987) and co-editor Of Plant Functional Types (1997).