Responses to climate change must now focus on reducing greenhouse gas emissions enough to avoid runaway impacts (avoiding the unmanageable) and on addressing the impacts that are already with us (managing the unavoidable). Managing natural ecosystems as carbon sinks and resources for adaptation is increasingly recognised as a necessary, efficient and relatively cost-effective strategy. The Stern Review on the Economics of Climate Change recommended that governments develop policies for climate sensitive public goods including natural resource protection, coastal protection and emergency preparedness. The worlds protected area network already helps mitigate and adapt to climate change. Protected areas store 15 per cent of terrestrial carbon and supply ecosystem services for disaster reduction, water supply, food and public health, all of which enable community-based adaptation. Many natural and managed ecosystems can help reduce climate change impacts. But protected areas have advantages over other approaches to natural ecosystem management in terms of legal and governance clarity, capacity and effectiveness. In many cases protection is the only way of keeping carbon locked in and ecosystem services running smoothly. Without the investment made in protected areas systems worldwide, the situation would be even worse. Increasing investment through a partnership of governments, communities, indigenous peoples, non-governmental organisations and the private sector would ensure greater protection of these essential services. Evidence suggests that protected areas work: even since this report was completed, a new World Bank review shows how tropical protected areas, especially those conserved by indigenous peoples, lose less forest than other management systems. But these co-benefits for climate, biodiversity and society are often missed or ignored. This book clearly articulates for the first time how protected areas contribute significantly to reducing impacts of climate change and what is needed for them to achieve even more. As we enter an unprecedented scale of negotiations about climate and biodiversity it is important that these messages reach policy makers loud and clear and are translated into effective policies and funding mechanisms.