1. Next discussion group: Energy Shortages and You, will be held at the Central Avenue
Bakery, 174 Central Avenue, PG, on February 16, from 6:30 to 8:30 PM. The meeting is
free and the public is invited.
Global Warming--
A Few Facts You Should Know
Figure 1: Global temperature record as shown in the Wall Street Journal 10/26/05
That Earth’s climate is changing and that humans are causing most of the change, is not
controversial among climate scientists.
After decades of improving climate modeling and measurement, a broad and deep consensus
has emerged among climate scientists. I could hardly say it better than Naomi Oreskes did in an
essay on the subject in Science Magazine (Science, Vol 306, Issue 5702, 1686 , 3 December 2004):
Policy-makers and the media, particularly in the United States, frequently assert that climate
science is highly uncertain. Some have used this as an argument against adopting strong
measures to reduce greenhouse gas emissions. For example, while discussing a major U.S.
Environmental Protection Agency report on the risks of climate change, then-EPA administrator
Christine Whitman argued, quot;As [the report] went through review, there was less consensus on
the science and conclusions on climate changequot;. Some corporations whose revenues might be
adversely affected by controls on carbon dioxide emissions have also alleged major
Newsletter Editor—Mark Folsom. For more information call Mark, 831 648 1543

2. uncertainties in the science. Such statements suggest that there might be substantive
disagreement in the scientific community about the reality of anthropogenic climate change. This
is not the case.
The scientific consensus is clearly expressed in the reports of the Intergovernmental Panel on
Climate Change (IPCC).
…In its most recent assessment, IPCC states unequivocally that the consensus of scientific
opinion is that Earth's climate is being affected by human activities: quot;Human activities ... are
modifying the concentration of atmospheric constituents ... that absorb or scatter radiant energy.
... [M]ost of the observed warming over the last 50 years is likely to have been due to the
increase in greenhouse gas concentrationsquot;.
IPCC is not alone in its conclusions. In recent years, all major scientific bodies in the United
States whose members' expertise bears directly on the matter have issued similar statements.
For example, the National Academy of Sciences report, Climate Change Science: An Analysis
of Some Key Questions, begins: quot;Greenhouse gases are accumulating in Earth's atmosphere as
a result of human activities, causing surface air temperatures and subsurface ocean
temperatures to risequot;. The report explicitly asks whether the IPCC assessment is a fair summary
of professional scientific thinking, and answers yes: quot;The IPCC's conclusion that most of the
observed warming of the last 50 years is likely to have been due to the increase in greenhouse
gas concentrations accurately reflects the current thinking of the scientific community on this
issuequot;.
Others agree. The American Meteorological Society, the American Geophysical Union, and the
American Association for the Advancement of Science (AAAS) all have issued statements in
recent years concluding that the evidence for human modification of climate is compelling.
She also cites a study in which 928 abstracts of recent scientific papers were analyzed to
determine whether they disagreed with the consensus position—none did. In short, all the noise
you might be hearing from politicians and others, about the uncertainty or controversy in the
science, is either misinformed—or intended to misinform you.
Earth’s climate has changed abruptly and dramatically in the past.
Ice cores from glaciers and many other kinds of physical records have, in recent years,
convinced scientists (paleoclimatologists) that Earth’s climate has repeatedly gone through
large changes in remarkably short times. Changes of a magnitude that could substantially
disrupt our agriculture and economy have happened in less than a decade and stayed around for
centuries. The abstract from a review article in Science summarizes the situation fairly well
(Science 28 March 2003: Vol. 299. no. 5615, pp. 2005 – 2010):
Large, abrupt, and widespread climate changes with major impacts have occurred repeatedly in
the past, when the Earth system was forced across thresholds. Although abrupt climate changes
can occur for many reasons, it is conceivable that human forcing of climate change is increasing
the probability of large, abrupt events. Were such an event to recur, the economic and
ecological impacts could be large and potentially serious. Unpredictability exhibited near climate
thresholds in simple models shows that some uncertainty will always be associated with
projections…
Even though the projections of climatologists may seem tame and relatively predictable, it is
known that the Earth sometimes has amplified small forcing inputs into very big climate
Newsletter Editor—Mark Folsom. For more information call Mark, 831 648 1543

3. changes, and we don’t have any certain way of knowing when we might be approaching a
threshold where climate will suddenly flip to a different and potentially very unpleasant state.
There are signs that we may be crossing an important threshold.
One of the most alarming possibilities in this situation is that we could warm the atmosphere or
the oceans to the point where large natural stores of greenhouse gases could be released, adding
to those produced as a byproduct of our burning of fossil fuels. For instance, it is now well
known that there are vast stores of methane (which is many times more potent a greenhouse gas
than carbon dioxide) locked up in methane hydrates (a solid solution or “ice” of methane and
water) under deep, cold ocean water. Warming that deep water would release much of the
locked-up methane and lead to warming far beyond that currently projected by the best climate
models.
Though that deep-water warming could take considerable time, a more immediate threat is just
coming to light—the permafrost of the arctic portions of the northern continents is thawing—
and releasing gases. The following story introduces one possible way the Earth could amplify
the warming (NewScientist.com news service, 11 August 2005, Fred Pearce):
Climate warning as Siberia melts
THE world's largest frozen peat bog is melting. An area stretching for a million square
kilometres across the permafrost of western Siberia is turning into a mass of shallow lakes as
the ground melts, according to Russian researchers just back from the region.
The sudden melting of a bog the size of France and Germany combined could unleash
billions of tonnes of methane, a potent greenhouse gas, into the atmosphere.
The news of the dramatic transformation of one of the world's least visited landscapes comes
from Sergei Kirpotin, a botanist at Tomsk State University, Russia, and Judith Marquand at the
University of Oxford.
Kirpotin describes an quot;ecological landslide that is probably irreversible and is
undoubtedly connected to climatic warmingquot;. He says that the entire western Siberian sub-Arctic
region has begun to melt, and this quot;has all happened in the last three or four yearsquot;.
What was until recently a featureless expanse of frozen peat is turning into a watery
landscape of lakes, some more than a kilometre across. Kirpotin suspects that some unknown
critical threshold has been crossed, triggering the melting.
Western Siberia has warmed faster than almost anywhere else on the planet, with an
increase in average temperatures of some 3 °C in the last 40 years. The warming is believed to
be a combination of man-made climate change, a cyclical change in atmospheric circulation
known as the Arctic oscillation, plus feedbacks caused by melting ice, which exposes bare
ground and ocean. These absorb more solar heat than white ice and snow.
So—we’re already finding surprises that can make climate change faster and more severe than
expected. Here’s another—it appears that warming of the surface of the ocean is suppressing
the upwelling of nutrients from the cold deeper waters—and reducing the growth of plankton,
which are the base of the ocean’s food chain. That means that there may be a fairly large die-
off in our oceans, but also that a major sink for carbon dioxide (the most important greenhouse
gas) may be weakened—resulting in a still faster accumulation of the stuff in the atmosphere.
There’s evidence that the accumulation of carbon dioxide is accelerating:
(Published on Sunday, January 15, 2006 by the lndependent/UK)
Global Warming to Speed Up as Carbon Levels Show Sharp Rise
by Geoffrey Lean
Newsletter Editor—Mark Folsom. For more information call Mark, 831 648 1543

4. Global warming is set to accelerate alarmingly because of a sharp jump in the amount
of carbon dioxide in the atmosphere.
Preliminary figures, exclusively obtained by The Independent on Sunday, show that
levels of the gas - the main cause of climate change - have risen abruptly in the past four years.
Scientists fear that warming is entering a new phase, and may accelerate further.
…
The climb in carbon dioxide content showed up in readings from the US government's
National Oceanic and Atmospheric Administration, taken at the summit of Mauna Loa, Hawaii.
The measurements have been taken regularly since 1958 in the 11,400ft peak's pristine
conditions, 2,000 miles from the nearest landmass and protected by unusual climatic conditions
from the pollution of Hawaii, two miles below.
Through most of the past half-century, levels of the gas rose by an average of 1.3 parts
per million a year; in the late 1990s, this figure rose to 1.6 ppm, and again to 2ppm in 2002 and
2003. But unpublished figures for the first 10 months of this year show a rise of 2.2ppm.
Scientists believe this may be the first evidence that climate change is starting to
produce itself, as rising temperatures so alter natural systems that the Earth itself releases more
gas, driving the thermometer ever higher.
Warming is already harming us and other life on Earth.
• Some scientists believe that hurricanes and other tropical storms are becoming more
violent as a result of warmer ocean water.
• Coral reefs are under stress worldwide.
• The arctic ice is thinning and shrinking rapidly.
• Populations of animals in California coastal waters are changing rapidly.
• Tropical diseases are spreading into temperate zones.
• Mountain snowpacks are shrinking, making summer water supplies more erratic.
• Virtually all the spruce trees on Alaska’s Kenai Peninsula are dead.
• The majority of the pinion pines in New Mexico are recently dead.
• Sea levels are rising rapidly.
• Wildlife in the Farallon Islands is suffering starvation.
• Droughts and floods are becoming more severe.
• Personally, I’m feeling dismayed and alarmed—shouldn’t we be doing something?
We can do a lot to slow this process—you can help.
Some sources of good information:
Intergovernmental Panel on Climate Change http://www.ipcc.ch/
Real Climate http://www.realclimate.org/
Energy Bulletin http://www.energybulletin.net/index.php
The Oil Drum http://www.theoildrum.com/ (takes a little digging)
Cool It http://www.cool-it.us/index.php?refer=&task=carbon
Newsletter Editor—Mark Folsom. For more information call Mark, 831 648 1543