OlCharlie, who dwells at 4000' and has a personal interest in climate on the
mountain.
So he tries to keep us posted. Also he seems to think that the local paper
the Fresno Bee is one of the most reliable reporters on Sierra mountain
climate forecasts. see attached.
Here on the sea shore...i was recently talking with a professor of marine
biology and asked about the oceans ph going acid and was it really
happening? She acknowledged it was happening.
The implication is the oceans are dieing.
I then inquired could this be reversed...she didn't know how.... but maybe
it was possible.
We then talked or actually she did about how everything could return to a
balance for the oceans in hundreds of thousands of years..if not millions.
And I'm sure you also will find that a great comfort..
----- Original Message -----
From: olcharlie
To: larry lewis
Sent: Sunday, March 30, 2008 10:23 AM
Subject: climate change and the sierra's
Moving to cooler ground
Beloved fixtures of the Sierra may be forced up, or out, as the climate
warms.
By Mark Grossi / The Fresno Bee
03/29/08 22:24:00
The 2,000-year-old giant sequoias east of Fresno have survived warm spells
lasting centuries, but in just 100 years, global warming could snuff them
out -- along with many Sierra Nevada species.
Why? The current episode of climate change is moving faster than any warm-up
detected in the past 500,000 years, many scientists say. Many say car
exhaust and other global-warming emissions from human activities may be the
reason.
The rising temperatures probably will shorten the Sierra's long, snowy
winters and force mass uphill migrations by sequoias, Sierra bighorn sheep,
dusky woodrats, rabbitlike pikas and mountain yellow-legged frogs,
scientists say.
The warming could mean oblivion for those that can't cope.
"I avoid being an alarmist," said Nathan Stephenson, a U.S. Geological
Survey research ecologist at the agency's Sequoia National Park field
station. "But there's a chance sequoias won't survive at all if they can't
find the right soil conditions at higher elevations."
The bighorn sheep, another mountain icon, might be forced to move uphill
away from predators, perhaps marooning themselves on alpine islands away
from their food sources, according to scientists.
No one knows what will become of the small, hearty shrubs and animals above
11,000 feet if the Sierra's small glaciers disappear. Glacial ice has
dripped precious water into an arid alpine landscape for thousands of
summers, but it may last only a few more decades, scientists say.
The warming also probably will force pines and firs to move uphill, along
with vast communities of shrubs, herbs and grasses that support wildlife and
help purify California's air.
The San Joaquin Valley's poor air quality would suffer further if a warm-up
weakens many millions of mature trees, which then would become prone to
wildfires and insect infestations. Smoke from fires would foul the air, and
decimated forests would not filter pollution.
Another way the Sierra changes would affect people: With less snow, there
would be more precipitation in the form of rain. State officials may have to
consider expanding reservoirs to store more water.
"These changes are tied to the life cycle of nature, something that affects
all of us," said Lara Kueppers, an ecosystems scientist at the University of
California at Merced. "There are a lot of reasons to care about what
happens."
International visitors probably would notice a difference. They flock to see
giant sequoias and Yosemite Falls, which probably would begin peaking
earlier each spring in Yosemite National Park.
In the central and southern Sierra, tourists pump millions of dollars into
local economies, particularly around Yosemite, Sequoia and Kings Canyon
national parks. Yosemite alone has 3.5 million visitors a year.
In Sequoia National Park, four of the five largest trees in the world -- all
sequoias -- live in Giant Forest.
The world's largest tree is the General Sherman, 103 feet in circumference
at its base and more than 2,300 years old. The Sherman and the other giants
live in the Earth's last 75 natural groves of giant sequoias, most of which
are in the southern Sierra, perched above the Valley.
With widespread root systems, the old giants can tap water sources in many
directions during dry times. Their thick, cinnamon-colored bark offers
protection from fire, allowing them to live up to 3,000 years.
Birds, mammals, insects and other creatures make these massive trees the
center of their lives. For instance, a Douglas squirrel eats sequoia cones,
and the weasel-like pine marten preys on squirrels.
But as warming increases, the natural community will be strained. Sequoias
would lose their damp, cool habitat between 5,000 and 8,000 feet. The big
trees prefer deep, sandy soil at the edge of damp meadows or near streams.
Young sequoias would be forced to grow at higher, cooler elevations. But
above 8,500 feet, the soils become more shallow, and there are fewer wet
meadows or stream bottoms to provide the water they need.
The species has hung on during past warm-ups, relying on the moisture that
remained during more gradual shifts in climate, tree-ring analysis and other
evidence show. A more radical change could drain them of resilience and dry
up their water sources.
Sierra trees, in general, already are suffering from rising temperatures and
less precipitation, according to a study done by USGS ecologist Phillip van
Mantgem and Stephenson.
Fir and pine trees are dying at almost double the rate they did 20 years
ago, Stephenson said.
"My big concern is that we'll get caught off-guard as this warm-up
continues, and a lot of trees will die very quickly," he said. "What kind of
surprises will we get?"
John Wehausen is asking the same question about the bighorn sheep on the
east side of the Sierra. He is a researcher based at the University of
California White Mountain Research Station in Bishop, where he has studied
bighorns for three decades.
Wehausen's work helped to bring the sheep back from the edge of extinction.
In 1995, predators and disease had left only 100 in the Sierra. By 2006, the
population had quadrupled. But Wehausen wonders whether global warming will
wipe them out anyway.
The agile animals detect hunters such as the mountain lion with keen
eyesight. The sheep need a clear view, usually at 10,000 to 13,000 feet in
elevation, which is above the tree line.
Though they can feed at higher elevations, the sheep prefer to eat more
nutritious grasses and shrubs several thousand feet lower. They must balance
the danger of moving downhill among predators with the desire for better
food.
If trees and predators move higher, the sheep will lose some of their clear
views. Will the change also wipe out their high-elevation feeding areas?
Will they be forced downslope toward predators? Researchers don't know.
"The population is already vulnerable," Wehausen said. "We're very
concerned."
Wehausen, Stephenson and other scientists say the complexity of climate
change and the Sierra ecosystem makes it hard to predict the effects.
Will human activities speed it up? That question can lead to angry debate.
But nobody doubts that people contribute warming gases, such as carbon
dioxide, from cars, power plants and factories.
Nature already provides plenty of factors to analyze, including the oceans,
the sun, the rotation of the Earth and subtle climate cycles often spanning
thousands of years.
Scientists have learned about past warm-ups by studying geologic sediments,
growth rings in trees, pollen in layers from lake bottoms and cores from the
ocean floor and massive ice sheets in Antarctica and Greenland.
They say the planet has warmed and cooled hundreds of times over the last
million years. Indeed, climate change is not at all unusual, though some
warm-ups are longer than others.
For example, there was a warming period that spanned 35 to 40 centuries
following the last Ice Age. It moved quickly at the start, but the warming
might have taken several hundred years to peak.
The change now is moving much faster. The 1980s and 1990s were the warmest
decades in four centuries, says the National Academies of Science. The
average temperature has climbed about 1.5 degrees Fahrenheit worldwide in
the last 130 years, according to NASA's Goddard Institute for Space Studies.
Last year, the Intergovernmental Panel on Climate Change -- a U.N. network
of 2,000 scientists and more than 100 governments -- issued a report saying
that global warming already has begun changing life on Earth.
The panel said most of the warming since 1950 is "very likely" due to
human-related emissions from cars, power plants and other activities.
The panel's scientists estimate the temperature will climb 2.5 to 10 degrees
in the next century. That kind of warm-up would be more than 10 times faster
than any previously detected warm-up in the last 10,000 years, scientists
say.
"The speed and the magnitude are off the map," said Leslie Chow, a USGS
research wildlife biologist in the Yosemite field station.
Yosemite is hallowed ground for biologists to observe changes due to
warming. The park and its natural inhabitants have been left undisturbed for
the last century, protected from mining, logging and many other commercial
activities.
Ninety years ago, biologist Joseph Grinnell thoroughly surveyed the park for
wildlife. Between 2003 and 2005, biologist James Patton of the University of
California at Berkeley repeated Grinnell's survey.
Patton's work showed the piñon mouse and the dusky-footed woodrat have moved
to higher elevations in Yosemite -- the mouse 3,000 feet higher and the
woodrat 1,500 feet higher. About 60% of the creatures in the survey had
moved upslope.
Patton said he has studied animals in California for 40 years, and he has
never seen similar changes.
"I was surprised," he said. "I had no reason to believe that I would find
this much movement."
Patton said the movement is not necessarily related to the warming climate.
But he said he could make a connection, especially in light of other
warming-related phenomenon -- such as the melting glaciers.
Yosemite's glaciers are melting, says Hassan Basagic, a Portland State
University research assistant. The park's Lyell Glacier at the Sierra crest
has dwindled dramatically, said Basagic, who has been studying several
hundred Sierra glaciers for a number of years.
Sierra glaciers are tiny compared to those in Alaska, which are remnants of
the Ice Age that ended 10,000 to 12,000 years ago. The California glaciers
have been around for about 3,200 years, according to studies by glacial
geologists Douglas H. Clark and Niki Bowerman of Western Washington
University.
Basagic said the Sierra glaciers are tucked in granite bowls, called
cirques, protecting them from sunshine. He compares the glaciers with
photographs of the way they looked early in the 1900s.
To Basagic and others, the shrinking glaciers are strong evidence of
warming. If they go quickly, as experts expect, other changes won't be far
behind.
"On the whole, I would say glaciers already have lost about 50% of their
surface area," he said. "There won't be much of them left over the next few
decades if things keep going this way."
The reporter can be reached at mgrossi@fresnobee.com or (559)441-6316
