Global Warming Approaching




A

mong
scientists who keep tabs on the pace of global warming, anxiety
has been rising that the Earth is reaching an ominous threshold,
a point of no return (“tipping point” in the scientific
literature) at which various feedbacks accelerate the pace of warming
past any human ability to contain or reverse it. 


Carbon-dioxide
levels in the atmosphere are rising rapidly, fed by increasing fossil-fuel
use in the United States, melting permafrost, slash-and-burn agriculture
in Indonesia, and increasing wildfires, as well as rapid industrialization
using dirty coal in China and India. 


All
of this takes place amid an air of fossil-fueled complacency in
the United States halls of power, where global warming has been
ignored. In the meantime, Sir John Houghton, one of the world’s
leading experts on global warming, told the London

Independent


,

“We are getting almost to the point of irreversible meltdown,
and will pass it soon if we are not careful.” 


The
evidence of cascading climate change is most dramatic in the Arctic.
Inuit on far northern Baffin Island were surprised during the summer
of 2004 by the arrival of yellow-jacket wasps. Several Vespula intermedia


(yellow-jacket wasps) were sighted in Arctic Bay, a community
of 700 people on the northern tip of Baffin Island, at more than
73 degrees north latitude. Noire Ikalukjuaq, the mayor of Arctic
Bay, photographed one of the wasps at the end of August. Other people
in the same community also told him they had seen wasps at about
the same time. 


During
the summer of 2004, enough Arctic ice to blanket Texas twice over
disappeared, compared with the previous year. In the past, weak-ice
years often were followed by good-ice years when cold winters or
cool summers maintained or extended the icepack. This kind of balancing
hasn’t been occurring recently.  “If you look at
these last few years, the loss of ice we’ve seen…is rather
remarkable,” Mark Serreze of the National Snow and Ice Data
Center at the University of Colorado told Katy Human of the

Denver


Post

. This was the third year in a row with extreme ice losses,
pointing to an acceleration of the downward trend, Serreze said. 


Addressing
a Senate Commerce Committee hearing on global warming August 15,
2004, Sheila Watt-Cloutier, president of the Inuit Circumpolar Conference,
said, “The Earth is literally melting. If we can reverse the
emissions of greenhouse gases in time to save the Arctic, then we
can spare untold suffering.” She continued, “Protect the
Arctic and you will save the planet. Use us as your early-warning
system. Use the Inuit story as a vehicle to reconnect us all so
that we can understand the people and the planet are one.” 



Accelerating Feedbacks 



A

monitoring station on the summit of Hawaii’s Mauna Loa has
been tracking increases in the level of atmospheric carbon dioxide
for the past 50 years. These readings indicate sharp increases in
the rate at which the greenhouse gas has been accumulating in the
atmosphere. The recent increases—2.08 parts per million from
2001 to 2002 and 2.54 parts per million from 2002 to 2003—have
drawn the attention of climate scientists because they deviate from
the historic average annual increase of around 1.5 parts per million.
 


A
debate has arisen: are these increases an aberration or evidence
of an accelerating rate of carbon-dioxide buildup? Is this accelerating
rate of increase the first evidence of a “runaway greenhouse
effect” stoked by a series of feedback mechanisms that will
cause world-wide temperatures to rise at a much more rapid rate,
along with accelerating changes of climate, melting ice caps, and
quickly rising sea levels?


Several
effects of warming compound each other in synthesis. For example,
shrinking snow cover, with its high reflectivity, allows polar surfaces
to absorb more heat on sea and land. The warming of land surfaces
melts permafrost, which releases larger amounts of carbon dioxide
and methane. The cycle reinforces itself. 


Researchers
have reported in

Nature

that Earth’s ancient stores
of peat are gasifying into the atmosphere at an accelerating rate
that is adding significantly to the atmosphere’s overload of
greenhouse gas. Given the fact that one-third of the Earth’s
carbon is stored in far northern latitudes (mainly in tundra and
boreal forests), the speed with which warming of the ecosystem releases
this carbon dioxide to the atmosphere is vitally important to forecasts
of global warming’s effects. The amount of carbon stored in
arctic ecosystems also comprises two-thirds of the amount presently
found in the atmosphere. Its release into the atmosphere will depend
on the pace of temperature rise—and the Arctic, according to
several sources, has been the most rapidly warming region of the
Earth. 


During
2004, Michelle C. Mack and colleagues presented results in

Nature

of a 20-year fertilization experiment in Alaskan tundra during which
“increased nutrient availability caused a net ecosystem loss
of almost 2,000 grams of carbon per square meter.” While aboveground
plant production more than doubled under warmer conditions, “losses
of carbon and nitrogen from deep soil levels…were substantial
and more than offset the increased carbon and nitrogen storage in
plant biomass and litter.” According to this study, increased
releases of carbon to the atmosphere “primed” by increasing
decomposition of organic matter could accelerate the rise in atmospheric
carbon dioxide—and, therefore, warming. 





Greenhouse Gases and Wildfires



 




I

ncreasing
wildfires are accelerating global warming. Under some circumstances,
wildfires may emit more carbon dioxide than humankind’s contribution.
What’s more, many present-day computer simulations of climate
change usually do not take fires’ contributions into account. 


Widespread
wildfires during the summer of 2002 changed areas of the U.S. west
from a carbon “sink” (absorber) to a net carbon source,
as drought stunted tree growth, according to computer modeling studies
of fires in Colorado conducted by a team of researchers from Colorado
State University, the U.S. Geological Survey, and the National Center
for Atmospheric Research. “We’re using the western United
States as a case study area where climate and land use are interacting
in several interesting ways,” said NCAR senior scientist David
Schimel. Western lands, particularly evergreen forests, represent
about half of all U.S. carbon storage, he said. More carbon is freed
from storage during droughts, not only because more dry vegetation
burns, but also because plants deprived of water grow slower, absorbing
and storing less carbon in their tissues. 


Another
important source for carbon dioxide has been provided by Indonesian
fires that polluted air over Southeast Asia during the El Niño
years of 1997 and 1998. An area twice the size of Belgium burned
in Indonesia during 1997. Susan Page at Britain’s University
of Leicester, together with colleagues in England, Germany, and
Indonesia, analyzed satellite photos and data gathered on the ground
to estimate how much of the fire area’s living vegetation and
peat deposits burned. 


In
Indonesia, layers of peat as thick as 20 meters (66 feet) cover
an area of about 180,000 square kilometers (112,000 square miles)
in Kalimantan (Borneo), Sumatra, and Papua New Guinea (formerly
Irian Jaya). Page and colleagues used satellite images of a 2.5
million hectare study area in Central Kalimantan from before and
after the 1997 fires. According to their estimates, about 32 percent
of the area had burned, of which peat land accounted for 91.5 percent.
An estimated 0.19 to 0.23 gigatons of carbon were released to the
atmosphere through peat combustion, with a further 0.05 gigaton
released from burning of the overlying vegetation. Extrapolating
these estimates to Indonesia as a whole, the researchers estimated
that between 0.81 and 2.57 gigatons of carbon were released to the
atmosphere in 1997 as a result of burning peat and vegetation in
Indonesia. 


Page
and colleagues reported in

Nature

that the carbon dioxide
released by these fires was “equivalent to 13 to 40 percent
of the mean annual global carbon emissions from fossil fuels and
contributed greatly to the largest annual increase in atmospheric
CO

2


concentration
detected since records began in 1957.”


 


Robert
Cowen of the

Christian Science Monitor

wrote: “Drought
due to the 1997 El Niño was all that was needed to make the
circumstances right for a sustained conflagration when forest-clearing
fires were lit that year.




 


Page
and her colleagues explained the difficulty of calculating exactly
how much carbon dioxide the fires emitted, but the totals were massive,
especially when one adds to Indonesia’s fires the many others
that have burned around the globe, notably during North America’s
intense drought. The work of Page and colleagues has major implications
for climate-change modeling because, as they wrote in

Nature

:
“Tropical peat lands are one of the largest near-surface reserves
of terrestrial organic carbon, and hence their stability has important
implications for climate change. In their natural state, lowland
tropical peat lands support a luxuriant growth of peat swamp forest
overlying peat deposits up to 20 meters thick. Persistent environmental
change—in particular, drainage and forest clearing—threatens
their stability, and makes them susceptible to fire. This was demonstrated
by the occurrence of widespread fires throughout the forested peat
lands of Indonesia during the 1997 El Niño event.” 


Jack
Rieley, at the University of Nottingham, UK, believes that burning
peat in Borneo is a major factor in rapidly rising atmospheric carbon-dioxide
levels. As farmers continue to clear the forests by burning, the
bogs catch fire and release carbon for months afterwards. A biologist
from Borneo told

New Scientist

late in 2004 that the fires
have now returned after an earlier peak during an El Niño-provoked
drought in 1998. “During October [2004], the atmosphere around
Palangka Raya has been covered in thick smoke, with visibility down
to 100 meters. The schools have been shut and flights cancelled,”
said Suwido Limin from the University of Palangka Raya in the Indonesian
province of Central Kalimantan. 


The
fires in Indonesia have had other environmental effects as well.
Iron fertilization of Indian Ocean waters resulting from the massive
wildfires may have played a crucial role in producing a red tide
of historic proportions that severely damaged coral reefs, according
to Nerilie J. Abram and associates, writing in

Science

. Their
findings “highlight tropical wildfires as an escalating threat
to coastal marine ecosystems.” 


The
spread of human populations is aggravating fire dangers around the
world. The fires that ravaged much of Indonesia during 1997 and
1998 were caused, in part, by drought-provoked El Niño conditions.
They were intensified, however, by local farmers hired to set fires
at the behest of local developers to open forest land for farming
and grazing. The fires were illegal under Indonesian law if they
were set in protected areas—but not if they could be blamed
on El Niño, a natural condition. At least 29 companies later
were indicted for setting illegal fires in Indonesia’s rainforests. 


Page
and colleagues pointed out, “In Indonesia, peat land fires
are mostly anthropogenic, started by local (indigenous) and immigrant
farmers as part of small-scale land clearance activities and, on
a much larger scale, by private companies and government agencies
as the principal tool for clearing forest before establishing crops.”
During the unusually long El Niño dry season of 1997, many
of these “managed” fires spread out of control, “consuming
not only the surface vegetation but also the underlying peat and
tree roots, contributing to the dense haze that blanketed a large
part of Southeast Asia and causing both severe deterioration in
air quality and health problems.” 


Commenting
on Page’s study in

Nature

, David Schimel and David Baker
of the National Center for Atmospheric Research in Boulder, Colorado
noted that two other independent studies of atmospheric carbon-dioxide
concentrations during that time period support the conclusion that
the fires were a major contributor to atmospheric carbon-dioxide
levels. Schimel and Baker told Cowen that computer climate simulations
assume that processes which emit carbon dioxide and remove it from
the atmosphere operate smoothly and continuously. Episodic events
such as wildfires play havoc with such simulations. 


At
present, no climate modeler knows exactly how to factor catastrophic
events in small areas that release carbon dioxide that has been
locked away in peat or other carbon and methane reservoirs into
world-scale forecasts of greenhouse-gas levels. Such events can
evidently have a huge impact on the global carbon balance, Schimel
and Baker believe. During 1997 the growth rate of carbon dioxide
in the atmosphere was double the usual rate, reaching its highest
level on record to that time, in large part because of these peat
fires. Most of the carbon injected into the atmosphere during the
Indonesian fires resulted from burning peat rather than combustion
of trees. 



The Kyoto Protocol 



G

lobal
greenhouse-gas emissions are rising and evidence of a warming planet
are developing much more quickly than world diplomacy has been able
to address them. The snails-pace nature of consultative diplomacy
combines with the fact that we feel the results of fossil-fuel effluvia
perhaps 40 years after the fact (through a complex set of natural
feedbacks) to create a trap in which human responses to global warming
take place several decades after nature requires them. 


Given
these circumstances, the Kyoto Protocol may be a climatic dead letter,
even though its approval by Russia in September 2004 produced world-wide
implementation on paper. Russia joined 124 other countries in ratifying
the protocol and, with its 17.5 percent share of world-wide carbon-dioxide
emissions, raised the world percentage to slightly more than 60
percent, above the 55 percent required to bring Kyoto into force.
Seven years after its negotiation in 1997, however, the only sizable
countries that have come close to meeting Kyoto Protocol target
emission reductions have been Great Britain and Germany. Most other
signatories have not met their goals and many third-world countries
(India and China among them) are not bound by its provisions. 


The
Kyoto Protocol has become more of a political rallying cry than
a serious challenge to global warming, which is developing much
more quickly than diplomacy can adapt. Even if the protocol was
to be fully implemented, a projected temperature rise of 2 degrees
Celsius by 2050 would be shaved only by 0.07 degree Celsius, according
to calculations by atmospheric scientist Thomas M.L. Wigley. In
other words, the Kyoto goals are only a small fraction of the reduction
in emissions required if world-wide temperature levels are to be
stabilized during the 21st century and afterwards. 


Governments
around the world have argued over climate-change policy for two
decades. The United States, which produces between one-fourth and
one-fifth of the world’s greenhouse gases, has ignored the
Kyoto Protocol. In the meantime, global emissions of carbon dioxide
from fossil-fuel combustion had increased by 13 percent above 1990
levels by the year 2000, mainly due to huge pollution increases
in third world nations, as China and India industrialize rapidly
on a power base that is fueled mainly by cheap, dirty coal. 


Increases
in greenhouse gas emissions would have been higher between 1990
and 2004, except for the collapse of former state socialist economies
in Russia and Eastern European nations during the period. Carbon-dioxide
emissions for the period rose by 17.8 percent in the United States,
from 4.8 billion tons in 1990 to 5.7 billion tons in 2000, while
Western European emissions rose by 3.9 per cent. As a result of
the dissolution of the Soviet Union and the resulting economic collapse
in former Soviet nations and Eastern Europe, carbon-dioxide emissions
in these nations fell from 3.7 billion tons in 1990 to 2.6 billion
tons, a drop of 30.6 percent. 


Emissions
of carbon dioxide and other greenhouse gases from Europe, Japan,
the United States, and other industrialized countries could rise
by 17 percent from 2000 to 2010, despite measures in place to curb
them, according to a United Nations report. “These findings
clearly demonstrate that stronger and more creative policies will
be needed for accelerating the spread of climate-friendly technologies
and persuading businesses, local governments, and citizens to cut
their greenhouse gas emissions,” said Joke Waller Hunter, executive
secretary of the United Nations Climate Change Convention.





Bruce E. Johansen
is the author of the forthcoming



Global Warming in the
Twenty-first Century



(Praeger Publishers).