While Rush Limbaugh, Sarah Palin, Donald Trump, Jim DeMint and other famous climate change-deniers have a laugh over their triumph over global warming, the rest of us are freezing and wondering what's going on.
People asked the same question two years ago when most of the US was crushed under the deepest snow seen in decades.
The quick, easy answers to those who think it can't be cold and snowy if the planet is warming are: "weather is not climate"; and climate change is a world-wide phenomenon, not a local one - it's summer in the Southern Hemisphere right now and Australia is withering in 120 degree heat.
But the reality is much deeper than these superficial observations.
“As the Earth gets warmer and more moisture gets absorbed into the atmosphere, we are steadily loading the dice in favor of more extreme storms in all seasons, capable of causing greater impacts on society,” said Jeff Masters, director of meteorology for Weather Underground, back in 2011. “If the climate continues to warm, we should expect an increase in heavy snow events for a few decades, until the climate grows so warm that we pass the point where it’s too warm for it to snow heavily.”
Scientists point to a warmer Arctic - with much less ice - that's pushing cold down our way rather than staying up north. Due to decades of melting ice (because of human-caused greenhouse gas emissions), the Arctic ice cap is much smaller and is surrounded by warmer water.
Less sea ice and more warmer water means there's more moisture - and heat - in the atmosphere, which can modify how air circulates there, says Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colorado.
A significantly warmer Arctic means there's less temperature differential between north and south, which weakens west-to-east winds, resulting in a "wavier" jet stream, posits Jennifer Francis, who studies the relationship between the Arctic and global climate patterns at Rutgers University’s Institute of Marine and Coastal Science.
While the jet stream used to sit consistently below the Arctic - keeping cold air north of it and warmer air south, it's now "wavier," allowing cold air to push way south.
This winter's brutal cold isn't just a US phenomenon. Winter storms are also pounding the UK and Europe had historically cold, snowy winters over the past few years. Meanwhile, Scandinavia is enjoying an unusually warm winter. That shows the wavy pattern of the jet stream, says Francis.
Kevin Trenberth, senior climate scientist at the National Center for Atmospheric Research thinks the jet stream is changing more because of moisture and heat in the air than temperature differential, but while scientists haven't sorted out the exact reasons for the change, they agree on this:
"Research suggests the air around the Arctic is becoming less and less stable in the winter, and cold Arctic air is able to break through to the United States, Canada and Northern Europe," says the Union of Concerned Scientists.
“This kind of pattern is going to be more likely. Extremes on both ends are a symptom of climate change. Wild, unusual temperatures of both sides, both warmer and colder,” Francis says.
“The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question,” says Trenberth. “All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.”
"This is just the beginning," of what life with the impacts of climate change will look like, warns Jeff Masters.
Read our article, Scientists Say Climate Change Makes Major Snowstorms More Likely.
For a simple explanation of the key points, read Wonk Blog.
Read more to understand how climate change works: