The highest summit of Mount Kilimanjaro was once completely covered in ice. But since 1912, more than 80% of the mountain’s ice cover has melted, disappearing at an even faster rate in recent decades. Photographer Yann Arthus-Bertrand’s aerial photographs show how climate change has impacted the environment. He says, "It’s too late to be pessimistic — really too late. We have to be a part of the solution."

Watch his talk for more stunning photos »