What's particularly odd is that the past several years have brought us peaks in late October, or else double peaks, with the final one around October 24. Fall colors had apparently shifted 10 days later than our traditional Columbus Day weekend long-term average peak, to match the extended growing season of recent years. Yet another manifestation of global warming, we figured.
So why do we now get an early foliage peak? With mild temperatures and ample rainfall except for a two-week dry spell in August, and no insect plagues this year, surely the trees can't be very stressed. Is this merely the first of another double peak - with the remaining green maples and oaks not destined to turn for weeks to come? Who knows?
Paul Huth, Mohonk's famous naturalist (did you see the major story about him and the Mohonk station gathering meteorological and other data for a century, in the September 16 New York Times?) said last Monday that the trees are doing the same thing there. He's not sure what's going on either, and thinks it might be due to that dry spell five or six weeks ago. Less-healthy trees or those on thinner soil are perhaps manifesting the stress that they got then. If so, we're observing, in effect, a huge laboratory "slide" where weak trees are being color-stained. One thing's for sure: It's quite unusual.
It's tempting to tie it in with the odd sunspot cycles that we've had of late. Sol has been unusually quiet during the sunspot minimum that has now persisted for three years. Lack of spots correlates with cooler weather here on Earth; we've known this for a long time.
The new 2009 edition of the Old Farmer's Almanac even predicts, in a major article, that this "quiet sun" period will continue for at least another decade or two, with the sunspot maximum due in 2011 or 2012 below normal, like the last one. They present graphs showing that worldwide temperatures march in lockstep with the sun's output, and use it to make the dramatic and probably unmerited prediction that we're in for an extended period of global cooling.
Although I'm the Astronomy editor of that publication, I was not asked my opinion prior to publication of that article. Seems to me that the explosive, runaway CO2 buildup in our atmosphere will ultimately prevail and make us much warmer, not cooler - even though worldwide temperatures have only gone up a paltry one degree Fahrenheit in the last century. Perhaps this currently quiet sun will deliver a global warming reprieve for some years, followed by...well, no one knows for sure.
We're like audience members in a grand, fascinating and rather disquieting play - whether we look around, or gaze up at the heavens.