Yale Environment 360: For 25 years, photographer Peter Essick has traveled the world for National Geographic magazine, with many of his recent assignments focusing on the causes and consequences of climate change. In a Yale Environment 360 photo essay, we present a gallery of images Essick took while on assignment in Antarctica, Greenland, and other far-flung locales. The photographer says that what most struck him was the dedication of the scientists who have committed themselves to documenting the effects of global...