Broad swathes of the US have been affected by heavy snowfall, ice, freezing temperatures, and high winds as a major weather system hit the country over the weekend. Disruptions spilled into the week, as Storm Blair continued to sweep eastwards on Monday.
Some 60M Americans faced weather alerts across 30 states, from Kansas and the south to the East Coast.
Forecasters say these winter storms have been caused by what's known as a polar vortex — a swirl of ultra-cold air that typically stays penned above the north pole — straying down into North America. Studies suggest this is caused by global warming and rising temperatures in the Arctic. More must be done to counter the severe and increasingly dangerous effects of climate change.
While some suggest that the straying of polar vortexes is caused by global warming, nothing is conclusive. The phenomenon has only been studied since the 1950s and the available data is simply not enough to substantiate a clear judgement. Weather systems are remarkably complex, and the most reliably effective course of action is to ensure that infrastructure is robust enough to survive the unexpected.