Air Date: Week of November 11, 2005

Fall foliage has faded in recent years. Host Steve Curwood turns to scientist Barry Rock at the University of New Hampshire to learn why.

Transcript

CURWOOD: It’s Living on Earth. I’m Steve Curwood. I live in northern New England, where usually by this time of year there’s been a spectacular show of changing colors of leaves. But not this year. In fact, things look, well, someplace between sort of light brown and dark brown in much of the area.

So to find out what’s going on I thought we would connect with Barry Rock. He’s a professor at the University of New Hampshire in the Complex Systems Research Center there. He’s also a botanist and a biologist, who’s been living in New Hampshire for years, and he too says the foliage just isn’t what it used to be. Hello there, professor.

ROCK: Hello Steve, how are you?

CURWOOD: Good, but I’m really disappointed by this foliage. And can you help me explain this? What is going on? Why are the trees just sort of turning brown this year?

ROCK: What’s going on here is that we’re simply having warmer falls than we’re used to, and those warm falls have really prevented the spectacular color displays that we come to expect.

CURWOOD: So what exactly makes for good color change in leaves? It should be colder, I guess. What else?

ROCK: One factor, change in day length, always happens. It’s like clockwork. And the leaves go from green to some other color. But where the weather comes in is when it’s cold, especially if we’ve had a frost or two. That really sharpens the color, because it essentially destroys the chlorophyll quickly and then those other yellow and orange pigments come screaming through. And that hasn’t happened this fall.

CURWOOD: So what are the weather factors that have all come together here, then, to make this lack of a show?

ROCK: Well, we’re in a current global warming period, and when you look at the globally warmest years it looks like 2005 is probably going to be No. 2. Those are all falls in which we’ve not had spectacular color.

I don’t want to frighten our listeners, but at the University of New Hampshire we’ve been working with some climate models that project one hundred years into the future. And one of them projects a warming over the next one hundred years of six degrees Fahrenheit. The second one projects a warming of 10 degrees Fahrenheit.

Our listeners are probably thinking six degrees, 10 degrees, what’s the big deal? Tomorrow’s going to be six to 10 degrees different than today. But these are annual average temperatures, and, to put this into perspective, if we look at the 30-year average temperature of Boston, 1961 through 1990, and you add six degrees to that, you get the current 30-year average temperature for Richmond, VA. And if you add 10 degrees to that, that’s the 30-year average temperature for Atlanta, GA.

I think the bottom line is if the climate models are at all close – and we’re coming to have more and more faith in these models as the days go by – then New England will change in very fundamental ways. We won’t have our ski seasons, we won’t have our maple syrup – we won’t have our maples. If things continue the way they are going now – so-called business as usual scenario, and we keep burning fossil fuels – we’re going to be saying goodbye to our beautiful fall foliage displays.

CURWOOD: So next year or the year after or the year after, there probably will be at least some time when all the colors come back. There’ll be a great year. What are the things to look for, say that summer—the spring or summer—that would point to maybe a great year for color?

ROCK: Well, what you’re looking for is a good growing season, some frosts that come maybe middle of September. And that’s when you want to make your reservations to show up on Columbus Day weekend. The fall color displays will be spectacular. You just have to hope it doesn’t rain because it’s a wet blanket so to speak, if you will.

CURWOOD: Barry Rock is a professor at the University of New Hampshire in the Complex Systems Research Center. Thank you so much, professor.

ROCK: Thank you Steve, it’s been a pleasure.