Tuesday, September 2, 2008

Climate Change in California

From my Series on Global Warming in California
(aired Fall 2006)

To many Californians, the Sierra Nevada is a special, even sacred place. It helped inspire the American preservation movement. Today, millions of people flock to its national parks, perhaps lured by the idea of wild nature, untrammeled by man. But as humans alter the world’s atmosphere, changes are a foot in Sierra parks. KPCC’s Ilsa Setziol hiked to treeline in Yosemite to bring us the second report in our series on global warming in California.

SETZIOL: Natural forces sculpted the land we know as Yosemite, over millions of years, into some of the planet’s most dramatic scenery. Glaciers cut into granite; snow-fed rivers carved out canyons. The glaciers have retreated, but snow fields continue to shape the Sierra. On a Summer day, Jan Van Wagtendonk of the U.S. Geological Survey leads me up Parker Pass on the eastside of the park.
(creek sound, with birds)

WAGTENDONK: Look at all the lupine and onions there along the stream.
It’s still spring up here. Here it is midAugust andtheflowers are in full bloom. ..It’s nice to be able to come up here and experience spring all over again.

SETZIOL: Fed by slowly melting snowfields, creeks here rush and gurgle in the summer. They water meadows, and sustain amphibians, and other animals through the dry season.

There’s a lot of uncertainty about what will happen with human-induced climate change. But one of the surest projections is loss of snow. Climate researchers say by the middle of this century the Sierra snow pack could decrease by roughly a third. Jan Van Wagtendonk says that could be a big problem.

WAGTENDONK: Much of the vegetation … depends on that snow melt. Mostly in the upper montane zone, for metering out of the water, through early summer, allows the red fir forest to sustain themselves. If all that shifts to rain and the rain goes downhill in the wintertime, they’ll be much less water available.

(sound of walking)
SETZIOL: As we climb from 9 to 10 to 11,000 feet, we discuss global warming projections for Western forests: larger fires…the possibility of new diseases moving up the mountains as they warm…stress on animals.

WAGTENDONK: the mountain yellow-legged frog would be affected dramatically if the streams dry up sooner.

SETZIOL: Then the forest falls away, and we emerge onto a pass between rocky peaks. Twisted vegetation, stunted by wind and cold, clings to thin soil. Reclining under a vast blue sky, snowfields bask in the sun.

WAGTENDONK: I never cease to be amazed. Always in awe of the grandeur.
(call of nutcracker)

SETZIOL: A trio of Clark’s nutcrackers perches in some white bark pines.

SETZIOL: so he’s gleening the seeds.
WAGTENDONK: out of the cone. He’s cleaning the pitch off his bark.

(bird sound under)
SETZIOL: The bird and the tree depend on each other. The nutcracker lives off the pine’s seeds. To store them for winter, the bird caches them in the ground, planting some seeds that otherwise would have remained locked in cones, or eaten by squirrels. Van Wagtendonk says global warming threatens both species in the Sierra.

WAGTENDONK: The white bark pine is very sensitive to summer heat. If the climate continued to be too warm over long extended period of time, they would be squeezed of the top. The way the white bark pine goes will be the way the Clark’s Nutcracker will have to go.

SETZIOL: Along with polar animals, species that live on the tops of mountains are most at risk from warming. Scientists are already documenting changes. (Although it’s unclear how much of current warming can be attributed to human activities instead of natural variability.) Jim Patten of UC Berkeley discovered some Sierra mammals have moved their ranges upslope more than a thousand feet in the last century. It’s a harbinger of how nature will respond to human-induced warming. A cute little cousin of the rabbit, the American pika, is losing ground. Scientists think it’s because it can’t tolerate warmer summers.

PATTEN: If it is indeed responding directly to temperature. That is an animal that’s going to get pushed off the crest of the Sierras. You get up to 14,000 feet and there’s no place to go. They’ll go extinct in the Sierras, and they’ll go extinct through out most of their range in the lower 48 in the US.

SETZIOL: Also at risk says Jim Patten: the alpine chipmunk.

PATTEN: It’s limited to the central sierra, it doesn’t occur outside the Yosemite, Sequoia Kings area. And so once it’s gone. It’s extinct forever.

(wind sound)
SETZIOL: At the top of Parker Pass the wind careens through gaps in the granite. Jan Van Wagendonk of the US Geological Survey rests at the lip of a turquoise lake.

WAGTENDONK: We’re at parker pass lake, a glacial tarn. Right at the point where the glaciers came through this area…And the snow is still here. Beautiful, beautiful day.

SETZIOL: Reluctantly, we turn to go. Van Wagtendonk tells me Yosemite’s climate has shifted cooler, warmer, drier, over hundreds of thousands of years. So, I ask him…why worry about global warming?

WAGTENDONK: I don’t want to be responsible for it. No! These ecosystems evolved over time without our intervention, we don’t want to make it worse for them one way or another.

SETZIOL: We descend. Past the chattering nutcrackers…down into the rustling pines…along the edges of meadows…and across creeks of steady, flowing, waters from above.
(bird and creek sound)

From Yosemite National Park, Ilsa Setziol, 89.3, KPCC

Find the audio and the rest of the series on the KPCC News Specials page.

Recommended Reading: The Weather Makers: How Man Is Changing the Climate and What It Means for Life on Earth by Tim Flannery (Atlantic Montly Press)

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