When it’s unseasonably warm, people I meet everywhere in the Aspen area — on the streets, in the gondola, at parties, at the grocery store — tell me about how they agree that global warming is indeed real. But when it’s cold, a different chorus seems to take over.
As temperatures drop, a very predictable response resonates through the Elk Mountains: “Global warming can’t be real if it’s this cold.”
This is both anecdotal and a classic mix-up. “Weather” is what one experiences when one steps outside. “Climate” is the long-term pattern playing out over decades and centuries. Conflating the two is one of the fastest ways to show a scientist that you have no idea what climate change actually is.
During just one of the multiple winter storms this year, more than 200 million Americans — from Texas through the Midwest into the Northeast and Mid-Atlantic — have navigated heavy snow, freezing rain and bitter Arctic air. States of emergency were declared across dozens of states, flights were canceled by the thousands and, at the height of this storm, more than one million customers were without power.
The impacts have been especially disruptive in places that don’t usually see this kind of winter weather. A friend in Washington, D.C., told me he was stranded for 10 days because his car was frozen in 7 inches of ice. That particular storm was linked to multiple deaths and disrupted daily life across a huge portion of the country. This is serious, dangerous weather — and acknowledging this does not in any way undermine climate science.
Here’s the part that often gets lost: The global warming our planet is absolutely experiencing does not mean that we won’t have any cold days. Rather, it means that the planet’s average temperature is rising, over time. And by that measure, the evidence is solid and undisputed.
Over the past century, Earth has warmed steadily, decade by decade. Each of the last 10 decades, in fact, has been warmer than the one before it, with the fastest warming happening over the past 50 years. This data shows up everywhere — cities and rural areas, land and oceans, across the globe. Taken together, the conclusion is unavoidable: The planet is significantly hotter today than it was 100 years ago, and the trend is accelerating.
And yes — counterintuitively — a warmer planet can actually help produce certain kinds of extreme cold and heavy snowfall. Scientists have found that the poles are warming faster than the mid-latitudes, which weakens the temperature contrast that drives the jet stream. When that jet stream becomes wobbly and more unstable, it’s easier for Arctic air to spill farther south than usual. That’s how you end up with intense cold snaps and powerful winter storms in places that aren’t built for them.
Add more moisture to the mix, and things escalate quickly. Since the 1970s, there’s been a clear increase in water vapor near Earth’s surface, closely tracking rising global temperatures. Warmer air holds more moisture, which means storms have more fuel. Sometimes that fuel falls as rain. Sometimes it falls as feet of snow.
This is especially true for major coastal winter storms, which thrive on the contrast between cold air over land and warmer, moisture-rich air over the ocean. As ocean temperatures rise, they supply even more heat and moisture to these systems, boosting snowfall totals and storm intensity.
So when a lay-person points to a snowstorm and declares it “proof” that global warming isn’t real, what they’re actually doing is focusing on a single moment while ignoring decades of data. Climate change doesn’t mean fewer extremes — it means more instability. And the storms currently happening all around the world are exactly what climate instability looks like.
Is there something you can do about it? Yes, you can support organizations working to alleviate the causes of climate pollution; proudly talk about your own carbon-abatement strategies; get your facts straight regarding the proven science and — especially for my fellow Coloradans — enjoy a good powder day — when that atmospheric river blesses us with some fresh snow.
Jacquelyn Francis is the founder and executive director of Climate Curve, a local nonprofit. Visit climatecurve.org for more information.