至少25人死亡！美国22个州宣布进入紧急状态 超1.3万架次航班被取消！

Core Points - A severe winter storm sweeping across much of the United States since January 23 has resulted in at least 25 fatalities [1] - The storm has led to widespread power outages, affecting nearly 700,000 users as of January 26 [4] - Over 22 states have declared a state of emergency, with more than 13,000 flights canceled due to weather impacts [4] Group 1: Storm Impact - The winter storm has brought significant snowfall, sleet, and low temperatures, with predictions of snowfall exceeding 305 millimeters in severely affected areas [4] - The storm's intensity and scope are described as the most severe of the winter season, with temperatures in states like North Dakota and Minnesota dropping below -45 degrees Celsius [4] - Officials warn that severe cold and ice could lead to serious transportation and power disruptions in affected regions [4] Group 2: Climate Context - The storm is attributed to the expansion of the polar vortex, which can occasionally move south into the U.S. due to climate change [5] - Some experts argue that while global warming is occurring, extreme cold events will still happen, albeit less frequently [5] - Climate scientists indicate that the increase in extreme cold events in the eastern U.S. is linked to warming in the Arctic, which affects climate system fluctuations [5]