What will Earth's population be in 2015? When will oil, coal, and other fossil fuels run out? How can we improve everyone's health? This book looks at how waste and pollution can overwhelm natural processes, at the benefits and limitations of the 3Rs of reduction, reuse, and recycling, and the action being taken at local and global levels. This series explains the pressure that population growth and unsustainable development are putting on the planet's resources and the environment. There's particular emphasis on challenging readers to think 'What would you do?', case studies and ideas for further research, and advice on how to think critically about these complex subjects.