Human population growth and increased consumption are placing major stresses on the environment and society. The human population has grown from 200 million in 1 AD to over 6 billion today, driven by improved nutrition, sanitation, and medicine. This growth and increased affluence have caused unsustainable levels of resource consumption and pollution. Technology and engineering will be central to monitoring environmental problems, developing sustainable solutions, and predicting the uncertain future over the next 50 years.