Yes, climate change can supercharge a winter storm. Here’s how.
A massive freezing storm is developing across the United States, stretching from the southwest to the northeast and plunging much of the country into a deep freeze until early next week. The Weather Channel warns that more than 230 million people, or two-thirds of the country’s population, could be affected by the system, which produces heavy snowfall and “catastrophic” ice accumulations. The Northern Plains could see wind chills below -50 degrees Fahrenheit, according to the National Weather Service. It also warns of widespread travel and electricity disruptions, which will make the situation even more dangerous for people who cannot heat their homes.
If you feel like you’re at the North Pole right now, that’s because you kind of are. Swirling above the Arctic is a mass of very cold air known as the polar vortex. This is surrounded, and usually trapped, by a strong wind called a jet stream, which is located at a lower level in the atmosphere. This separates cold Arctic air from warmer southern air.
Things are changing in the North, however, where warming is four times faster than the rest of the planet, a phenomenon known as Arctic amplification. Decreasing sea ice exposes darker waters, which absorb more solar energy than ice. Warming in the region therefore leads to even greater warming, and so on. Indeed, Arctic sea ice has reached record levels. So today there is less of a temperature contrast between the Arctic and warmer southern regions than before. “When this happens, the jet stream tends to meander a lot, allowing very cold air to descend southward,” said Ayumi Fujisaki-Manome, an earth scientist at the University of Michigan.
Research suggests the jet stream has weakened in recent times, making it wobblier. This could increase the likelihood of weather phenomena such as those we are currently experiencing, although it remains an active topic of research within the scientific community. “The problem is it’s really hard to show whether this is happening or not,” said Jacob Chalif, who studies the phenomenon at Dartmouth College. “The amplification in the Arctic really started in the ’90s, and we only have really solid records of the jet stream going back to 1979.”
That only leaves researchers with about a decade to use as a baseline, Chalif added, whereas in an ideal world they would still have many years to determine trends. So last year, Chalif led a study using machine learning to analyze climate records going back to 1901. The team found that before 1979, there were many years when the jet stream became wavy, and sometimes it was even more pronounced than it is today. “In other words, the impact of climate change on the jet stream, I think, remains unclear,” Chalif said. “I don’t think we’re sure yet about making the jet stream more wavy.”
However, climate change is increasing these types of storms in general. The research group Climate Central notes that right now the waters of the Gulf of Mexico and the Pacific off Baja California are exceptionally warm, and this is made much more likely due to humanity’s carbon emissions. This loads the atmosphere with extra moisture, which collides with the system moving down from the Arctic to supercharge the storm. Additionally, as the atmosphere warms, the more moisture it can hold and the more precipitation can result from extreme weather events.
So when President Donald Trump sees this polar vortex unfolding and asks in an article on X: “WHAT HAPPENED TO GLOBAL WARMING??? The answer is that climate change is largely a factor in the brutal conditions that 230 million Americans could experience in the days to come. “Judging climate change by a cold storm is like judging a baseball season by a single inning,” Kaitlyn Trudeau, senior research associate for climate science at Climate Central, said in a statement. “But climate change is having a tangible impact on this storm.”
