Professor Stephen Hawking thinks the human species will have to populate a new planet within 100 years if it is to survive. With climate change, pollution, deforestation, pandemics and population growth, our own planet is becoming increasingly precarious. Planet Earth has been home to humankind for over 200,000 years, but with a population of 7.5 billion and counting and limited resources, this planet might not support us forever. In this... see more