This week, Barack Obama made history, becoming the first US president ever to visit the Arctic Circle. His three-day trip to Alaska was aimed at pushing world leaders to take action at the upcoming climate conference in Paris. Global warming is already taking its toll on the world's glaciers. Next, we head to an Inuit village threatened by flooding from melting ice. Finally, we head to Los Angeles, the latest city to throw its hat into the ring in a bid to host the 2024 Olympic Games.