Weather

Warm start to November follows trend of warming in recent decades

The rest of this week continues the trend of milder-than-average weather. Highs this afternoon and again on Friday could near 70 in many places. It doesn’t reach 70 degrees very often in November. On this day, it’s only hit 70 eight other times, and interestingly, we haven’t reached that mark this century. You’d need to go back to 1999 to find a 70-degree reading on November 3rd.

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Today is of course just one day. If we take a broader inspection of November, it’s clear New England is warming up. Last year we had to wait until November before many areas even saw a frost. Portland, Maine didn’t get a frost in October for the first time in officially recorded history.

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Last night I ran some numbers and produced a few charts showing how Novembers are warming. You can discuss the causes of the warming and even argue them, but the numbers themselves don’t lie.

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Sometimes I think I’d like to live 1,000 years to see what it all looks like in the future. What’s interesting to me about the increasingly warmer Novembers is what implications to plants this may have if the trend continues. While temperatures can become warm, the amount of light won’t change. If the trend of warming of three-tenths of one degree every 10 years continued, in a thousand years, November’s average temperature would be about the same at July’s is today. Of course, there are many other factors at play, and while it’s plausible this trend continues, perhaps through a combination of less man-made C02 and a shift in the present underlying warming trend, it doesn’t.

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For the sake of the post, let’s explore a much warmer fall and winter three centuries from now. In the future, even far-northern areas would be able to grow crops all winter. Currently, I can winter over spinach by simply covering it with row cover and plastic. This is true even after last February, the coldest recorded. While it would take 10 centuries for November to be like July, it would take about a third as long for November’s temperatures to resemble October.

Biologists continue to study the impacts of warming in the short-term, but a thousand years from now, if the trajectory we are on continued, the flora and fauna that would exist in this part of the country would likely be vastly different.

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Light is critical, but temperature is a bigger player. The pattern of ultra violet light is for all intents and purposes constant. We know how much solar radiation reaches the top of the Earth’s atmosphere on any given day. This isn’t likely to change, even in the year 3215.

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We continue to lose not only minutes of possible sunlight, but also the strength of that light, which weakens each 24-hour cycle. Even though this is going to be a warm week, the rate of growth is not what it is during the 15-hours of daylight in late spring. Grass, kale, and other greens still grow, albeit a lot slower.

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We can sort of see the future. A peak into a much warmer New England is just a plane flight away. If you’ve been to Paris or London in the winter they have similar amounts of light, but the lack of cold means a very different landscape in a very different world.

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