The End of Fall Colors?

Maybe, via nc links:

That’s partly why the specter of declining foliage tourism is so worrisome to New England scientists and tourism leaders these days. Both climatologists and phenologists—who study the effects of seasonal changes on plants and animals—are becoming increasingly concerned about the effect of rising temperatures on Thoreau’s spectacular “autumnal tints.”

First, our signature crisp fall air seems to be turning less, er, crispy. The Union of Concerned Scientists has found that northeast temperatures have been rising by about 0.5 degrees Fahrenheit per decade since 1970, with winter temperatures rising at a rate more than double that. The group says that regional temperatures could rise another three degrees within the next 30 years, and up to 12 degrees by 2099.

This warming is already producing a constellation of region-specific effects, including a longer growing season and compromised sap production. Forest aesthetics are not immune. The New England Climate Coalition predicted a few years ago that if temperatures continue to climb unabated, “the fall foliage for which the region is famous will disappear as birch, maple, and spruce species migrate north or die out altogether.” New Hampshire’s Department of Environmental Services warned in 2008 that the state’s hardwood trees could move north by up to 300 miles. In Maine, scientists have enlisted citizens to document the effects of climate change by monitoring their own backyards.

Not only will the current forests simply move north. The colors themselves could fade. The chemicals that create yellow, gold, and orange colors lie dormant within tree leaves all year long. In the spring and summer, the green color—chlorophyll—overwhelms them. Then in autumn, the greens fade in response to shortening days and the underlying colors become visible to the naked eye. Under most conditions, those yellows and pale oranges will emerge in the fall no matter what. The chemical that produces red leaves, anthocyanin, is different. That color must be produced each year by a precise, yet not fully understood, combination of sugar, temperature, and light.

This may be a minor impact of global warming/climate change, I'm more concerned about food production.