Our systems are failing. Old models - for education, healthcare, government, food production, energy supply - are creaking under the weight of modern challenges. As the world's population heads towards 10 billion, it is clear we need new approaches.

From Brazilian favelas and rural India to one of the toughest housing estates in Britain, acclaimed writer and futurist Mark Stevenson set out to find remarkable innovators who are pioneering new ways to make our world more sustainable and democratise access to resources and knowledge.

He explains how patients are helping each other find the best treatments by using the medical equivalent of a dating website; how rural farmers are exceeding the yields of the Green Revolution with techniques inspired by a Jesuit priest; how a community has made itself completely independent from the big energy suppliers by turning bark that used to just rot on the forest floor into electricity; and how urban farming and a community-run food system has turned a city on the brink of collapse into a food capital.

He paints an enthralling picture of what can be done to address the world's most pressing dilemmas and offers a much-needed dose of down-to-earth optimism.