In just 25 years, dozens of places will be too warm to host the winter Olympics

By Laura Paddison, Samuel Hart, CNN (CNN) — Jessie Diggins is an endurance athlete. The Olympic cross-country skier describes the intensity of suffering her sport can inflict as a “pain cave.” It doesn’t frighten her; she’s used to digging deep, she can control the pain. What does terrify her, however, is how rapidly her sport