By David Ayer
All of us working in EDN’s Washington, D.C., office last week felt first-hand what climate change is already doing to our planet. In DC on Thursday, January 31, the wind chill factor dipped below zero. Like many others in the United States, we saw record low temperatures, then the weather completely reversed for us and the temperature reached 74 degrees Fahrenheit (23.3 Celsius) less than a week later — in what was the hottest recorded day on that date in DC.
The reason behind this recent cold snap in the United States and similar cold weather events: fluctuations in what is called the polar vortex. Polar vortexes are the two wide areas of swirling cold air above the north and south poles, which are generally kept in place by a strong jet stream. However, due to global climate change, the jet stream has started to fluctuate, allowing for events like last week’s extreme cold snap. And that is how you get the record-setting temperatures all of us were hiding from on that frigid Thursday.
The fact that climate change is having an impact on species populations can at times be a hard concept to grasp, with phenomena like coral bleaching and minute temperature changes in the ocean seeming like abstract ideas. But every once in a while, we can take a second to notice that there are impacts happening right before our very eyes.
Human beings can, given the resources, stay safe by staying inside, wearing layers, and cranking up the heat. But what happens to the rest of the species on Earth that don’t have homes and offices to hide in?
Animals and plants aren’t as prepared for the temperature to drop so precipitously. While animals from this region are accustomed to cold weather, these extreme dips of low temperature can be more deadly. Sometimes, harsh weather can be beneficial for animal populations. The old, diseased, and disabled are the first to die; the survivors who go on to breed after the weather will be stronger, healthier, and more adapted to extreme conditions. But when the temperatures reach extremes — at numbers that are nowhere near the normal operating conditions — the story can be different. Even the strongest animals and other outdoor species may not be able to weather the conditions. Some populations may have already been stressed by another threat; without the genetic diversity that comes with larger populations, these species may not have individuals that are able to survive the extreme conditions.
It is too soon to tell what the final impact of the polar vortex will be on the wildlife that experienced it. We know it was too cold for some animals. Polar bears have evolved to live on the North Pole and red pandas can withstand frigid temperatures on the Himalayan mountains, but both stayed indoors at the Pittsburgh zoo during this recent cold snap. The species that range from the middle of the United States to the east coast are not from the poles or the Himalayas, and most did not have the option of going inside.
As for local flora and fauna, we can also look at previous cold snaps to see impacts. There is a well-documented history of animals and plants struggling in unexpected extreme cold weather events. This is especially true of species that have more recently spread into the area, as a result of our warming climate or because their previous habitat was encroached upon by humans. The Virginia Opossum is a good example of this. They are able to handle the cold of a typical winter, but are not adapted to the extreme cold seen in polar vortex events. The most vulnerable part is the opossum’s bare tail; many opossums lose their tails when it gets unusually cold.
It may be a few more weeks or months before we can determine the full impact of this most recent cold snap. What we do know is that, just like humans, animals and plants have a threshold of temperatures in which they can survive. If our actions are causing temperatures to unexpectedly plummet below their threshold, we may have to consider changing our behavior for the benefit of all life on Earth, including our own.