Global estimates of wilderness reserves have declined rapidly over the last 300 years, largely due to human population growth and demand for food and resources. And human population, now at seven billion people looks set to rise further still to nine billion or more by 2100. Sustainability and resilience are not just words that apply to resources, but to the whole planet including wilderness. Our concluding chapter makes cogent and clear arguments in favour of wilderness protection and rewilding as one means of maintaining a healthy global ecosystem, contrary to some of the ideas of the green modernist movement that puts people at the centre and which believes that technology and human ingenuity will come to the rescue. While some of the policy mechanisms to do this are already in place (e.g. REDD+) we suggest that these require better and stricter application informed by mapping campaigns. Despite wilderness being a largely fuzzy concept, lines on maps are needed to protect natural ecosystems and their wildlife. We conclude with a review of the chapters in the book and how they, together, address these concerns, before making some predications as to future developments.