Global warming, was RE: marxism-digest V1 #5242 #1

Mark Jones markjones011 at
Mon Dec 9 08:21:53 MST 2002

Jose G. Perez wrote:
> 1. Runaway warming is simply not, not, I repeat NOT accepted by anyone I'm
> aware of who is professionally involved in studying climate change.

Oh really?

What climatologists and paleoclimatologists are prepared to say in public,
and the fears they express privately, are often 2 different things. As a
group they have been attacked, intimidated and rubbished for scare-mongering
by US-led fossil fuel, governmental and corporate and media interests, who
have done all they can to destroy the credibility of the IPCC. Some
climatologists I know personally experience deep private anguish because
they feel caught between the Scylla of being portrayed and attacked as
'alarmist', 'ultimatistic' etc, and the Charybdis of feeling they are part
of a professional trahison des clercs, too craven to tell the truth as it
really is.

Here is some potted history, which shows just how wrong, repeat wrong, you
are, Jose.



(06/01/1992) Scientists fear a coalescing pattern of positive global warming
feedbacks could cause "runaway" global warming, threatening the entire basis
for life on Earth. Scientific consensus on global warming was formalized in
May 1990 in an assessment by the Intergovernmental Panel on Climate Change
(IPCC). Its authoritative early warning set most of the world's governments
negotiating for a Global Climate Convention in February 1991. Amid rapid
advances in scientific research, the IPCC was asked to prepare an updated
report by January 1992.

When climate scientists gathered in Guangzhou, China, to complete the second
IPCC report, the political scrutiny was intense. Some governments (like
Germany and Austria) looked for confirmation that their policies of cutting
carbon dioxide emissions - the gas is modern civilization's major
contributor to global warming - were sound. Foot-dragging governments (like
the United States and Saudi Arabia) sought evidence for their arguments that
uncertainties about global warming permit delays in efforts to cut
greenhouse gas emissions.

The central question the 300-plus scientists who collaborated on the 1992
IPCC report had to tackle was whether the "early warning" in the 1990 report
could be confirmed. The scientists, from 44 governments, concluded that it
could. However, the subsequent February session of the climate negotiations
in New York City ended in deadlock, primarily because the United States
refused to concede the need for setting targets and deadlines for limiting
carbon dioxide emissions.

Foot-dragging governments, by definition, advocate go-slow approaches to
global warming issues. They argue that the science is uncertain, and that
global warming is an unproved process. This view is a travesty of the
science behind global warming. Climate models on which future warming
estimates are based attempt to simulate a complex interactive system. They
are not perfect, but they give us a clear warning that business-as-usual
emissions of greenhouse gases means taking an appalling gamble with the
environmental security of the generations to come.

Many experts' concerns go beyond the ecologically dangerous rates of warming
now forecast by all the world's climate modeling centers. Many scientists
ask if the abundance of greenhouse gases might lead to a worst-case scenario
with runaway warming in the next century. How close are we to a
self-sustaining warming that would be beyond human control? Recently,
Greenpeace collected scientists' gut feelings (something that would never
find their way into an institutional document).

In a poll of 400 climate scientists conducted by Greenpeace International
during January and February 1992, almost half (45 percent) said that a
runaway greenhouse effect is possible if action is not taken to cut
greenhouse gas emissions. And more than one in ten of those polled believe
that such a scenario is probable. The poll included all scientists involved
in the 1990 study of the Intergovernmental Panel on Climate Change, and
others who have published on issues relevant to climate change in Science or
Nature during 1991.

The worst-case hypothesis is viewed as a serious consideration by many of
the world's best climate scientists, but they have been unable to
successfully communicate that to policy-makers. Meanwhile, best-case
advocates have become regular fixtures in the global media simply by
advocating the minority view - rejected in the IPCC's reports - that natural
climatic dampening mechanisms will suppress the heat-trapping abilities of
the greenhouse gases.

A feedback is a natural component of the climate system that is activated by
other system components. The extent to which climate models can simulate and
predict reality depends on their ability to simulate these feedbacks. In a
warming world, negative feedbacks can act to suppress warming. (An example
might be the formation, in a warming atmosphere, of cloud types that reflect
more solar radiation back into space than other types.) Positive feedbacks
amplify the warming - the release of now-trapped greenhouse gases from
melting tundra in the far north would be an example.

The feedbacks generated by water vapor and clouds are incorporated in all
modern global circulation models. Water vapor concentrations are generally
projected to increase in a warming atmosphere: a positive feedback. Clouds,
according to the IPCC, can provide positive or negative feedbacks, and it is
in simulating clouds that most of the current variance in climate models is
found. The ice-albedo feedback (the reflection of solar radiation back to
the atmosphere by ice) is also included in global circulation models. In
most, it is positive: a warmer world will involve shrinking ice cover,
lowering albedo, and reflecting less solar radiation. But many feedbacks,
especially biological feedbacks, are simply omitted from climate models
because they are too difficult to quantify, given the extent of our
ignorance of the climate system.

A minority of world-class atmospheric scientists subscribe to the best-case
analysis of feedback interactions. They suggest that the human-enhanced
greenhouse effect is a non-problem. Advocates of this view do not question
the buildup of greenhouse gases in the atmosphere, unprecedented since
humans first appeared on earth, which is measured and proven. Neither do
they question the heat-trapping capacity of the gases, which is based on
simple physics. Rather, the best-case advocates ask policy-makers to place
faith in the expectation that negative feedbacks will work to cool the

According to Richard Lindzen of MIT, for instance, a warming troposphere
will not produce more water vapor in the way anticipated by global warming
models. Instead, water vapor will be wrung from the lower atmosphere by the
increased vigor of atmospheric circulation. Lindzen and other advocates of
this view ask policy-makers to commit the environmental security of future
generations to a theoretical negative feedback concept which has been
rejected by a majority of their peers.

Global warming risk assessment is complex, unlike risk assessment associated
with the ozone depletion problem. Ozone depletion is represented by one main
variable: chlorine and bromine from halocarbons. The higher these chemical
concentrations, the lower the ozone concentrations. It is a proven process,
and the thinning ozone layer can be measured. Measurements in recent years,
in fact, have shown that atmospheric scientists have consistently
underestimated the pace and extent of ozone depletion. What if the
scientific community's underestimation of ozone depletion proves to apply to
global warming as well? Bad as the broad-consensus, best-estimate IPCC
prognosis is, what might the worst-case analysis of global warming be?

The main worry is that a coalescing pattern of positive feedbacks might be
awakened and continue unchecked by negative feedbacks. Some of nature's
carbon reservoirs are so huge that they could become involved, in principle,
in a runaway greenhouse effect. The world would simply go on warming,
placing a viable future for human and animal life on the planet at risk.

Consider the following: the world warms at the accelerated rates predicted
by the IPCC, and concentrations of carbon dioxide and other greenhouse gases
continue building up in the atmosphere. As the oceans warm, they are not
able to absorb as much carbon dioxide from the atmosphere as they do today.
This is a safe bet; the IPCC warns that this will be a positive feedback,
since carbon dioxide is less soluble in warmer water. [ECES note: This has
already begun to happen - see (09/03/2001) Researchers find sharp drop in
amount of carbon dioxide being absorbed by northern Pacific Ocean over past
15 years.]

Luck is not with us; a "plankton multiplier" effect begins. This is a drop
in net productivity (the creation of biomass by photosynthesis) in the
phytoplankton. It results from a reduced deep ocean nutrient supply to the
stabler-than-normal upper levels. Therefore, one of the two major carbon
dioxide "sinks" suffers a drop in its capacity to absorb carbon dioxide.
(Many scientists believe the plankton multiplier appeared suddenly at the
end of the last ice age, boosting average temperatures in the North Atlantic
region by as much as five degrees centigrade within as little as a century.)

This time, the effect worsens. Increased fluxes of ultraviolet radiation
penetrating the depleted ozone layer above the highly productive waters of
the Antarctic and sub-Arctic have seriously weakened the phytoplankton, thus
further shrinking the ocean's capacity for carbon dioxide absorption and
allowing more of the gas to accumulate, by default, in the atmosphere. This
is a major fear, now that ozone-depletion has been found to extend into the
spring, when phytoplankton bloom.

By now, ecosystems are responding to warming temperatures with increases in
soil and plant respiration in excess of normal photosynthesis, causing
further carbon dioxide accumulation in the atmosphere and boosting
temperatures above currently predicted rates. This excess respiration, like
all the foregoing feedbacks, was flagged as a positive feedback by the IPCC
in its 1990 report.

As temperatures rise, the tundra begins to melt faster than expected. More
carbon dioxide and now huge quantities of methane, a more potent greenhouse
gas, are emitted from the spreading wetlands and the increased oxidation of
organic matter. However, much depends on the behavior of water tables, for
flooded soils are capable of releasing 100 times more methane than dry
soils. [ECES note: widespread melting of Arctic tundra and permafrost has
indeed begun - see a number of the articles at Global Warming: Arctic.]

Now the reorganization of global cloud cover also works against us, creating
a new positive feedback factor. More high-altitude (noctilucent) clouds form
than do at the present time. They contain ice crystal distributions that
trap more heat in the atmosphere. According to the IPCC, this feedback could
go either way in a warming atmosphere, as much depends on the physics of ice
in clouds. In the worst-case analysis, luck is not with us. [ECES note: In
1993, scientists began reporting the unprecedented appearance of noctilucent
clouds - formerly only seen above 40 degrees latitude - as far south as
Colorado and Utah. See this article below.]

Meanwhile, profound aridity has begun to develop at many latitudes. Though
one might expect that vegetation would prosper from the carbon dioxide
"fertilization effect," in fact it suffers because of other factors such as
decreasing soil moisture, increasing forest fires, multiplying plant pests,
and increased exposure to ultraviolet-B radiation. Hence, land plants are
less able than expected to absorb carbon dioxide from the atmosphere. Even
higher concentrations of the gas build up, driving temperature levels higher
than previously projected.

By now, today's children are in their 50s and 60s, some of them the
policy-makers of the day. Some regions, as would be expected from the
variability of climate, have warmed only slightly. Most, however, are
suffering profound ecological trauma. Warming effects are such that the
"short-term winners" - areas where the climate has become more temperate and
crop yields have risen - are now deteriorating as a result of a drastically
blighted world economy. Cuts in greenhouse gas emissions have long since
been internationally implemented, but they are still not deep enough to
stabilize atmospheric concentrations. Net economic savings from
energy-saving measures and enhanced energy independence have been lost in
the bill for environmental damage.

Bad luck continues. Tropospheric chemistry has started to work against
humankind. The hydroxl reservoir (the atmosphere's cleansing agent,
oxidizing a host of polluting gases), has come under stress from excess
quantities of methane, hydrochlorofluorocarbons, hydrofluorocarbons, carbon
monoxide, and nitrogen oxides in the atmosphere. The quantities of these
gases increase by default, as do their lifetimes, boosting global warming
still further. [ECES note: In May 2001, scientists reported that hydroxl
levels declined 10 to 24 percent between 1979 and 2000. See this article in
Pollution: Air for more.]

Meanwhile, the pollution assault continues. Still more carbon monoxide and
nitrogen oxides are emitted by the ever-expanding global automobile fleet.
These gases are precursors for tropospheric ozone, a powerful greenhouse

By now, the Arctic is appreciably warmer. The ice around the fringes of the
ice cap is beginning to retreat, reducing the Arctic's albedo and providing
more positive feedback. The Arctic ocean warms still further and the ice cap
begins to show signs of thinning. At this stage, one of the worst feedbacks
is awakened. On the Arctic continental shelf, submarine methane hydrates
start to destabilize. Methane hydrates are ice-like solids comprising a
network of water crystals with methane gas trapped under pressure.
Geologists have shown that an unspecified but apparently huge quantity of
methane is isolated from the atmosphere in these hydrates. Warming can
destabilize them under the permafrost and in shallow high latitude seas.

The measurements of the World Climate Monitoring System detect unprecedented
acceleration of atmospheric methane concentrations. In emergency session the
United Nations votes sweeping measures for worldwide greenhouse-gas
reductions. But it is too late. A runaway greenhouse effect has been

The point is not that a worst-case scenario will happen, but that it could
happen. Consider some of the reservoirs in the planet's carbon cycle. The
pre-industrial atmosphere contained around 580 billion tons of carbon for
thousands of years. Now it contains 750 billion tons. The coal and oil
reserves waiting to be burned total 4,000 billion more tons of carbon. We
cannot afford to burn more than a small fraction of this, yet oil and coal
companies are looking for still more.

Carbon in soils amounts to 1,500 billion tons, a good proportion of it at
risk of positive feedback. Nearly 90 billion tons is exchanged each year
between the atmospheric reservoir and the 39,000 billion-ton reservoir in
the oceans. Approximately 100 billion tons of carbon circulates between the
atmosphere and the approximately 750 billion-ton reservoir in land plants.
Almost a quarter of all atmospheric carbon is cycled down into the
terrestrial and marine biota each year. Even small changes in this quantity
could have huge implications for atmospheric concentrations.

Though not yet addressed in the IPCC science-advisory process, the
worst-case scenario is central to formulating a policy response. In
evaluating military threats throughout history, policy response has been
predicated on a worst-case analysis. The standard military yardstick must
also apply to environmental security.

The Japanese government's report, "Action Program to Arrest Global Warming,"
released in October 1990, refers on its first page to the potential
magnitude of the stakes. "It is essential," it says, "to steadily promote
feasible measures so that damage from global warming may not become
prominent and give birth to irreversible situations." The tension here
between the "feasible" and the "irreversible" is clear, and it reflects the
fact that 13 ministries and agencies are represented by the committee
planning the Japanese government's response to climate change.

What seems "feasible" to the Ministry of International Trade and Industry is
not very far outside the present energy-industrial status quo. In contrast,
what seems "irreversible" to scientists of Japan's environment agency is
made clear in several of its publications. For example, the April 1991
report from Japan's Advisory Panel on Environment and Culture notes
"expansionism consists of damaging the environment without replenishing it.
If we refuse this definition of expansionism, we run the risk of creating a
crisis which will not stop with the ruin of one country, but will cause the
destruction of the entire planet and every living thing on it." Worst-case
analyses can creep into the language of governments, not just the language
of environmentalists.

But such examples are far fewer than the instances of governmental rhetoric
stressing the difficulties and economic costs involved in cutting emissions.
Unfortunately, policy-makers see the risks of responding to the threat of
climate change as equal to, or even greater than, simply waiting to see what
happens in a business-as-usual world. A sad potential epitaph for humankind
thus emerges: "We wanted to save the world. But our leaders told us it would
be too expensive."

The Intergovernmental Panel on Climate Change (IPCC) did not deal with the
influence of biological feedbacks on global warming in its 1992 report. One
sentence in the report read, "Biological feedbacks have not yet been taken
into account in simulations of climate change." Unfortunately, the
implications of this omission, one way or the other, were not elaborated for
the edification of policy-makers.

This was not the case two years ago, when the 1990 IPCC report was finalized
in Windsor, England. There, several eminent ecologists and paleoecologists
contributed. The section on confidence in simulated models included the

"Because natural sources and sinks of greenhouse gases are sensitive to a
change in climate, they may substantially modify future concentrations [of
greenhouse gases]. ... It appears likely that, as climate warms, these
feedbacks will lead to an overall increase rather than a decrease in natural
greenhouse gas abundances. For this reason, climate change is likely to be
greater than the estimates we have given." In other words, the panel's "best
estimate" of global warming is likely to be an underestimate.

The largest biological system on the planet is that of marine phytoplankton;
it produces more biomass - 104 billion tons of carbon per year - than all
terrestrial ecosystems combined, which generate 100 billion tons of carbon
annually. Any reduction of photosynthetic activities in the phytoplankton
could amplify global warming in two ways. First, it would suppress the
photosynthetic sink that absorbs carbon dioxide, and second, it might
provide less dimethyl sulfide, a gas which generates condensation nuclei for
the formation of clouds.

We now know that marine phytoplankton in the northern hemisphere will be
exposed to intense ultraviolet-B radiation in the spring, just when they are
at their most productive. The depletion of the protective ozone layer above
the Arctic as a result of chlorofluorocarbon (CFC) production is the
culprit. A recent U.N. Environment Program (UNEP) report warns that since
most phytoplankton organisms do not have ultraviolet radiation receptors,
they cannot avoid deleterious radiation that "penetrates deeper into the
water column than has been previously measured." The report, submitted as
part of the scientific review process under the Montreal Protocol agreement
to protect the ozone layer by limiting CFC use, adds that this radiation
exposure causes massive inhibition of photosynthesis, as measured in both
field and laboratory studies.

How big could this feedback be? We have no way of knowing. The UNEP report
merely observes that "a hypothetical loss of 10 percent of the marine
phytoplankton would reduce the oceanic annual uptake of carbon dioxide by
about 5 billion tons - an amount equal to the annual emissions of carbon
dioxide from fossil fuel consumption."

[ECES note: This article was written by Dr. Jeremy Leggett, who took his PhD
in earth sciences at the University of Oxford in 1978, and joined the
faculty at Imperial College of Science and Technology, where during an 11
year career he won two major awards for his research on the geological
history of oceans, sat on several advisory committees for the UK
government's Natural Environment Research Council, and consulted for the oil
industry in the UK and Japan. During the mid 1980s, he became increasingly
concerned about environmental issues in general, and global warming in
particular, a process culminating in 1989 in his leaving academia to join
the international environment group Greenpeace as Scientific Director of
Greenpeace International's Climate Campaign (1990-1994) and Director of its
Solar Initiative (1995-1996). Between 1993 and 1995 he also served as a
guest lecturer at Cambridge University’s Centre for Global Security. During
1996, he served as a Visiting Fellow at Oxford University’s Green College
Centre for Environmental Policy and Understanding, working under the UK
Prime Minister’s environment advisor, Sir Crispin Tickell. In 1996, Leggett
won the US Climate Institute’s Award for Advancing Understanding. He left
Greenpeace at the end of 1996 to set up a private solar energy company.He is
author-editor of the best-selling "Global Warming," (Oxford University
Press, 1990, published in English, Japanese, German, French, Portuguese,
Italian, Czech and Russian), and "Climate Change and the Financial Sector"
(Gerling Academy Verlag, 1996).]

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