Lingering juncos

Normally by this time of year the juncos have all headed north, but I’ve noticed that the last few years they’ve remained around here a bit longer each time. Not the juncos which wintered here — they left about two weeks ago just as the first wave of phoebes arrived — but migrants from somewhat farther south.

This phenomenon of later springs (and snowier winters) has been increasingly evident for some years now and is not limited to birds. Several years ago the alfalfa in our fields would have been 12 to 16 inches tall by now, yet this year it has barely greened up, continuing the trend of later growth.

Similarly, the bloom dates for our fruit trees have retarded by at least two weeks. This has been a consistent trend since 2004, with R-squared >70% for you statistics junkies.

I strongly suspect we have returned to a generation-long cooling trend as driven by the Pacific Decadal Oscillation. In my life as a farmer and gardener I’ve now experienced both the cool cycle of my youth — remember all the talk about the “coming ice age” back in the 1970s? — and the warm cycle of my younger adulthood. May I live long enough to see another warm cycle.

Of course we might not get one. We’re due for another multi-generation cold spell the last of which came in the late 17th century and was linked with a near absence of sunspots known as the Maunder Minimum. These things come along every three centuries or so and are not particularly fun, effectively shifting local climates to something like 500 to 1000 miles farther north.

One such cycle in the 14th century led not only to the plague and widespread famine — one result of which was the rise of militant Islam — but a cycle earlier to feudalism in Europe as peasants attempted to survive, and in the 4th and 5th centuries to the fall of both the Roman Empire and the Han Dynasty in China.

Serious stuff, and given that the current sunspot cycle is much later and weaker than expected … not particularly comforting. A few juncos and one spring do not make for a cycle, but they do seem to be somewhat like one dot in pointillist painting, and perhaps a harbinger of colder seasons to come.

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