Late aspen, early melting

 

Despite the best efforts of many concerned friends, I remain something of an agnostic on whether climate change is caused by humans or is part of a natural cycle. After all, on my daily walks with the dog along the Arkansas River, I can gaze across our wide valley and stare up the narrow valley of the North Fork -- where there was a big glacier a few thousand years ago which melted long before there was an industrial civilization to spew carbon dioxide and other greenhouse gases.

That said, those outings with the dog also provide some evidence of warming. We used to figure that the changing aspen would peak around September 15. For some years, though, it's been coming later in September. Here it is the 22nd, a week after the traditional peak, and the gold is just starting to show on the hillsides; the peak may come in another week.

Does that indicate a warming climate? Hard to say. The botanists tell us that the chemical changes that make the leaves turn yellow are not a result of temperature, but instead by the declining hours of sunshine as the days shorten in the fall. Temperature, and thus global warming, shouldn't be a factor.

But another local spectacle might be a result of climate change. On a 14,157-foot peak west of Salida, there is a seasonal snow formation called "the Angel of Shavano" that emerges as the winter snowpack melts.

Generally, it doesn't look all that cherubic. I've always though the Angel looked more like Woody Woodpecker, and my kids said it resembled the Grinch.

At any rate, old guidebooks up into the 1930s said the Angel was at its best around Independence Day. These days, it's pretty well melted by July 4, and reaches its peak around Memorial Day -- five weeks earlier.

That appears to be solid evidence of a warming climate.

And I'd like to know -- is there anything like this happening where you live?