Anyone living in the eastern United States has probably noticed how unusually warm it’s been this February. And it’s not just your imagination. There’s even a good way to visualize this.
The US Geological Survey has a neat set of maps, updated daily, showing how early spring has arrived in each state this year — an index based on plant events, like leaves appearing on trees and flowers blooming. In a swath of the country from San Antonio to New York City, spring arrived two to three weeks earlier than usual. In Washington, DC, spring arrived 22 days early:
Note that there could still be more frigid weather in the weeks ahead. The warmth we’re seeing now could merely be a “false spring,” only to be followed by a cold snap or frost. But what plants are doing right now is basically consistent with what they do in the onset of spring. And they’re doing it weeks earlier than normal.
On one level, this isn’t terribly surprising. As the USGS points out, scientists have known for some time that “climate change is variably advancing the onset of spring across the United States.” It’s one of the (many, many) indicators of a warming planet. “These findings are consistent with the fact that the instrumental record shows that 2016 was the hottest year ever recorded for the globe, and that it was the third record-breaking year in a row,” USGS notes.
Why does this matter? On one level, it’s just plain nice to have spring weather in February. But as the agency points out, these early spring onsets can have all sorts of wide-ranging impacts on human health and agriculture — both positive and negative:
For example, changes in the timing of spring can affect human health, bringing early-season disease-carriers such as ticks and mosquitos, and an earlier, longer and more vigorous pollen season. And while a longer growing season can result in increased yields for some crops, it is risky because of the higher likelihood of plant damage caused by late frosts or summer drought.
The early spring can also have unpredictable effects on wildlife. Some species will benefit; others will lose out:
Even something as seemingly simple and beautiful as flowers blooming earlier can disrupt the critically important link between wildflowers and the arrival of birds, bees, and butterflies that feed on and pollinate the flowers. Such changes may prove beneficial to some plants and animals, including some harmful invasive ones, but may be detrimental to others. Changes in seasons can affect economically and culturally important outdoor recreation activities, including affecting the timing of hunting and fishing seasons.
Back in 2014, Elizabeth Grossman wrote an excellent piece for Ensia on the weird disruptive effects of early springs. A series of “false spring” events in the Sierra Nevadas in the 1980s and 1990s, for instance, destroyed an entire population of Edith’s checkerspot butterflies — because it desynchronized when the butterflies emerged and when the flowers they rely on for food started blooming. One big question, Grossman writes, is whether species can adapt to these increasingly common early spring events — so far, some species have adjusted, but not all.
Now, the churlish thing to do would be to point out that these early springs are also harbingers of much more drastic changes to come — global warming, melting ice caps, flooded coastal cities, hellish heat waves, droughts, and much more. But eh, that can wait for another day. May as well enjoy things for now.
Me enjoying this weather but knowing our Earth is danger pic.twitter.com/Jy6bINvZ6C— breanna (@bre_lliant) February 19, 2017
Further reading: Robinson Meyer had a good piece on this: “Should you enjoy the warm winters of climate change?”