Scientists
Conclude Global Warming
Is “Unequivocal”
By Mark Rainer
12 February, 2007
World
Socialist Web
The
Intergovernmental Panel on Climate Change (IPCC) released the “Summary
for Policy Makers” from its fourth assessment report on science
of global warming and climate change February 2. The new report concludes
that global warming is “unequivocal” and strengthens the
previous assessment that most warming in the last 50 years is due to
human activity.
The IPCC report predicts
a greater frequency of heat waves, more intense tropical cyclones (typhoons
and hurricanes), the possible disappearance of summer Arctic sea ice,
increasing acidification of the ocean, and changing patterns of precipitation
that will cause an increasing number of draughts for some portions of
the world. Depending on the scenario, global temperatures will rise
between 1.8 and 4 degrees Celsius and sea levels will rise between 18
and 59 centimeters before the next century.
Established in 1988 by World
Meteorological Organization and United Nation Environmental Programme,
the IPCC assesses scientific, technical and socioeconomic information
relevant to the understanding of climate change. The IPCC’s report—the
most comprehensive of its kind—is an assessment of the current
scientific research on climate change and global warming. It draws upon
the work of 2,500 scientists from 130 countries and represents a broad
consensus within the scientific community. All scientific findings considered
by the IPCC and thus forming the basis of the report are peer-reviewed
results published in scientific journals.
The report notes that “scientific
progress since the TAR [Third Assessment Report] is based upon large
amounts of new and more comprehensive data, more sophisticated analyses
of data, improvements in understanding of processes and their simulation
in models, and more extensive exploration of uncertainty ranges.”
On the question of whether
humans are the cause of recent warming, the new report is nearly conclusive.
Improvements in computer simulations have led the IPCC to conclude that
the warming of the past 50 years is “very likely” due to
human activity. This means the authors are more than 90 percent certain
that recent global warming is caused by the burning of fossil fuels,
changes in land use, and agriculture. The previous report concluded
that anthropogenic warming was only “likely,” meaning it
was more than 66 percent certain.
The burning of fossil fuels
has been the primary source of increases in carbon dioxide—the
most significant contributor to global warming. Atmospheric concentrations
of carbon dioxide rose to 379 parts per million (ppm) in 2005. This
level “by far exceeds the natural range over the last 650,000
years (180 to 300 ppm) as determined from ice cores,” according
to the report, and represents a great increase over the “pre-industrial
value of 280 ppm.” Concentrations of other greenhouse gasses have
also risen over the last century, with methane rising to 1774 parts
per billion (ppb) and nitrous oxide rising to 319 ppb in 2005. This
is compared with pre-industrial levels of 715 ppb and 270 ppb respectively.
The report states, “Warming
of the climate system is unequivocal,” citing “observations
of increases in global average air and ocean temperatures, widespread
melting of snow and ice, and rising global mean sea level.” Notably,
“11 of the last 12 years (1995-2006) rank among the 12 warmest
years in the instrumental record of global surface temperature.”
The report correlates “an
increase of intense tropical cyclone activity in the North Atlantic
since about 1970” with “increases of tropical sea surface
temperatures.” It also links “increased temperatures and
decreased precipitation” with “more intense and longer droughts
over wider areas since the 1970s.”
The human impact of climate
change will be detailed in another IPCC report to be released later
this year. The summary released February 2 deals only with “The
Physical Science Basis” portion of the IPCC assessment. From drafts
obtained by the Age, an Australian newspaper, between 1.1 billion and
3.2 billion people will suffer water scarcity as a result of climate
change. Also, between 200 million and 600 million could suffer from
food shortages and 7 million could be affected by costal flooding. The
poor will be most affected by climate change.
Although the summary is directed
at policymakers, there is little sign of a change in course among major
contributors of greenhouse gas emissions, such as the United States,
Australia, China, and India. In a press conference held in response
to the IPCC report, US Energy Secretary Samuel Bodman accepted the findings
but rejected any kind of mandatory caps of greenhouse gas emissions.
Instead he suggested emission reductions should be tied to economic
growth, and should be achieved through “voluntary, market-based
products.”
Bodman made the correct point
that a self-imposed cap on emissions in United States will lead to shifts
in production where there are no caps. In this statement, he expresses
the logic of capitalism, which seeks the most profitable means of production
with little regard for the long-term environmental consequences. Despite
the Bush-appointed official’s boasts of investment in climate
research and energy technologies, greenhouse gas emissions have continued
to increase under the Bush administration.
Overall, the party affiliation
of the resident of the White House (Democrat or Republican) has not
impacted trends in greenhouse gas emissions. According to statistics
contained in the Environmental Protection Agency’s 2006 report
“Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2004,”
average yearly greenhouse gas emissions increased by 1.6 percent a year
under the Clinton-Gore. These trends have largely continued under George
W. Bush. As the EPA’s report notes, the driving factors in the
increase in emissions in the United States over the period 1990-2004
are a growing domestic economy and increased emissions from transportation
activities and electricity generation. Although the EPA produces an
inventory of greenhouse gas emissions, as is required by the United
Nations Framework Convention on Climate Change, there is no federal
regulation to limit greenhouse gas emissions.
The IPCC has issued three
previous reports, in 1990, 1995 and 2001. Governmental responses so
far to the IPCC’s continued warnings have been largely symbolic.
The only existing international agreement to reduce emissions, the Kyoto
protocol, is ineffective and flawed in its conception. The formation
of a new international agreement that works to significantly reduce
global greenhouse gas emissions faces insurmountable challenges within
the framework of the nation-state system, which pits country against
country and subordinates the protection of the environment to the interests
of private profit.
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