An exercise of interdisciplinarity at the crossroads of humans and the environment--this could be one definition of human ecology, as it is demonstrated within this book. Examples of different branches of human ecology are shown as feasible alternatives to understand the interactions of human culture and behaviour with the natural environment from all parts of the world. Current trends, ranging from climate change to ecological knowledge and environmental co-management are deeply exploited, using a diversified array of empirical case studies. Theoretical aspects are included and examined in every case, including the evolution of culture, values and webs of information within cultures. The central theme approaches and reveals the social, cultural, economic, and ecological processes which link human beings to their environment. From a mixture of practice and theory we emerge with alternatives to mitigate and prevent the accelerating negative changes currently witnessed on our planet, where increasingly fewer people are safe. More importantly, this book provides examples showing how those whose lives are deeply rooted on a direct natural resource dependency are the first to be affected by the global trend of environmental degradation. Small-scale fishers, farmers and herders from the tropics and from cold regions have their livelihood affected by global changes, regional politics and cultural exchanges. Whether and how they will survive, adapt, or embody such changes is not known and this is one more reason to include and involve local groups when searching for sustainable solutions. In a changing world, exploring current threats and impacts of human actions on the environment is a necessity, but bringing about alternatives, some of them already part of traditional human practices, is urgent and can turn to be a promising solution. Anthropology, sociology, and ecology come together in this book, where the unifying goal of theorizing and practising interdisciplinarity in human ecology is shown by, closely tracking examples of current trends and developments. This book is a harvest from the XV International Meeting of the Society for Human Ecology, engaging over 200 people from 27 countries from all continents, held in Rio de Janeiro, Brazil, October 4-7, 2007, organized by A. Begossi and P. Lopes, with the support of the Fisheries and Food Institute (FIFO) and the State University of Campinas (UNICAMP). This volume ends by indicating several lines of thought and of analyses on current subjects, as follows: sustainability in different cultural contexts and perspectives, methods towards approaching sustainable systems, and current global concerns. Those include agriculture in tropical areas (slash-and-burn practices), climate change, and nature and human behavioural patterns, among others.