This is a book about how we should address the great, and interconnected, global challenges of the twenty-first century.Our task, Sachs argues, is to achieve truly sustainable development, by which he means finding a global course which enables the world to benefit from the spread of prosperity while ensuring that we don't destroy the eco-systems which keep us alive and our place in nature which helps sustain our values.How do we move forward together, benefitting from our increasing technological mastery, avoiding the terrible dangers of climate change, mass famines, violent conflicts, population explosions in some parts of the world and collapses in others, and world-wide pandemic diseases?In answering these questions, Sachs shows that there are different ways of managing the world's technology, resources and politics from those currently being followed, and that it should be possible to adopt policies which reflect long-term and co-operative thinking instead of, as currently, disregard for others and ever-increasing barriers to solving the problems which we collectively face.It is a book which appeals equally to both head and heart, and one which no globally thinking person can ignore.