Transcript for the Piece Audio version of Climate Change: Affecting The Seasons?

Reporter: Robert Frederick
You might occasionally burn leaves or brush in your backyard, or even light up a campfire. But there are places in the world where people are burning things for months at a time, and no, it’s not by accident.

Interviewee: Ben Santer
slash-and-burn agriculture, clearing forests, burning in the Congo and in the Amazon fire up at certain times of year

Reporter: Robert Frederick
Ben Santer is a climate scientist who works at Lawrence Livermore National Lab in California. It’s not just forests burning for months at a time.

Interviewee: Ben Santer
Sulfate pollution — another thing with a lot of seasonality in the production of sulfur dioxide.

Reporter: Robert Frederick
by burning sulfur. Sulfur dioxide is used for preserving foods, including raisins, apricots, and prunes — keeping them from getting discolored. But it’s primarily for the production of sulfuric acid, which is important for a number of manufacturing purposes. But, Ben says, it all comes at a cost.

Interviewee: Ben Santer
There’s this rich information there that indicates that we’re seeing profound changes in seasonality.

Reporter: Robert Frederick
Because when we do things at certain times of year — like burn forests or produce sulfur dioxide — it may be that we’re affecting the natural cycle.

Interviewee: Ben Santer
On the timing of maximum temperatures, on the timing of stream flow, for example — runoff from snow-fed river basins with more runoff arriving earlier in the year — changes in the location of species, the timing of bird migration, flowering, and there’s this rich evidence from the biological world this stuff is happening.

Reporter: Robert Frederick
So Ben and his colleagues are starting to ask:

Interviewee: Ben Santer
Can we in some statistical sense really detect and attribute changes in seasonality to human activities?

Host: Robert Frederick
The observations are there. There’s data to move forward, but, Ben says this work is only just beginning.

Interviewee: Ben Santer
We just haven’t looked at that question from the physical sciences side of things.

Host: Robert Frederick
So while the balance of evidence gathered over decades suggests that our activities are having an effect on global climate, scientists are only just beginning to ask whether we’re affecting the timing of the seasons, too. I’m Robert Frederick.