The global population is higher than the Earth can sustain, argues the Director of the British Antarctic Survey in the first of a series of environmental opinion pieces on the BBC News website entitled The Green Room.
There are already too many people living on Planet Earth, according to one of most influential science advisors in the US government. Nina Fedoroff told the BBC One Planet programme that humans had exceeded the Earth's "limits of sustainability".
Over the next week the BBC News website will be looking at the issues raised by the growth in the world's population. But how are these changes affecting people's daily lives? BBC News speaks to seven people from around the world to hear their stories.