Introducing 'treeconomics': how street trees can save our cities

As a fight over 11 lime trees in Sheffield escalates, activists in cities all over the world are making the case for urban trees - to cut pollution, increase land value and even make you feel younger

Rustlings Road is aptly named. The street in Sheffield is lined with mature lime trees. Their whispering leaves are brilliant green in spring, then cast cool, dappled shade in summer and turn bright yellow in the autumn. But Sheffield city council wants to prune the street, and a dispute about 11 lime trees has turned into a citywide campaign, with more than 10,000 people urging the council to halt its roadside felling. I has also sparked a broader debate about what 36,000 street trees bring to a place that claims to be the most wooded industrial city in western Europe.

This tussle shows how urban trees are both treasured and in jeopardy like never before - beset by disease and spurious insurance claims, and too readily felled by cash-strapped local authorities which only see their potential cost rather than their contribution to climate, public health and even the wealth of a city. Ever since Roger Ulrich discovered in 1984 that hospital patients appear to recover more quickly from surgery in rooms with green views, a growing body of scientific evidence has demonstrated the health - and wealth - benefits of trees in cities.