Alok Jha is a self-described water obsessive, a scientist and communicator; he's made an art form of unpacking some of the most complex questions of our age. A fascination with water has taken him literally to the ends of the earth. A journey to Antarctica in 2013 came close to an unfortunate end. He joins a long list of remarkable science communicators, who try to make the incomprehensible sound simple. He and his wife recently had their first child, and somewhere in between all of this, he's penned the Water Book. 

Sheila Watt-Cloutier is an independent advocate on Inuit human rights. When she was growing up, she wanted to be a nurse and then a doctor, but that didn't pan out very well because she wasn't very good at chemistry, physics, or mathematics.

Watt-Cloutier lives in Iqaluit on Baffin Island in the Canadian Arctic. If the Arctic is the world's barometer, says Sheila, then the Inuit are the mercury, and she has campaigned tirelessly to get this message out, to explain to the world that climate change is not just an environmental concern, but very much a human one too. It is work that has made a mark globally and saw her nominated for the Nobel Peace Prize.