Global Warming

DEFINITION OF GLOBAL WARMING

SPEEDING UP THE PROCESS

GROWING EVIDENCE OF GLOBAL WARMING

ANOMALIES AND REFUTATIONS

SCIENTIFIC CONSENSUS

INADEQUATE ACTION AND NEEDED TRANSFORMATIONS

BIBLIOGRAPHY

Understanding the causes of and responses to global warming requires interdisciplinary cooperation between social and natural scientists. The theory behind global warming has been understood by climatologists since at least the 1980s, but only in the new millennium, with an apparent tipping point in 2005, has the mounting empirical evidence convinced most doubters, politicians, and the general public as well as growing sections of business that global warming caused by human action is occurring.

DEFINITION OF GLOBAL WARMING

Global warming is understood to result from an overall, long-term increase in the retention of the sun’s heat around Earth due to blanketing by “greenhouse gases,” especially CO₂ and methane. Emissions of CO₂ have been rising at a speed unprecedented in human history, due to accelerating fossil fuel burning that began in the Industrial Revolution.

The effects of the resulting “climate change” are uneven and can even produce localized cooling (if warm currents change direction). The climate change may also initiate positive feedback in which the initial impact is further enhanced by its own effects, for example if melting ice reduces the reflective properties of white surfaces (the “albedo” effect) or if melting tundra releases frozen methane, leading to further warming. Debate continues about which manifestations are due to long-term climate change and which to normal climate variability.

SPEEDING UP THE PROCESS

Global warming involves an unprecedented speeding up of the rate of change in natural processes, which now converges with the (previously much faster) rate of change in human societies, leading to a crisis of adaptation. Most authoritative scientific bodies predict that on present trends a point of no return could come within ten years, and that the world needs to cut emissions by 50 percent by mid twenty-first century.

It was natural scientists who first discovered and raised global warming as a political problem. This makes many of the global warming concerns unique. “Science becomes the author of issues that dominate the political agenda and become the sources of political conflict” (Stehr 2001, p. 85). Perhaps for this reason, many social scientists, particularly sociologists, wary of trusting the truth claims of natural science but knowing themselves lacking the expertise to judge their validity, have avoided saying much about global warming and its possible consequences. Even sociologists such as Ulrich Beck and Anthony Giddens, who see “risk” as a key attribute of advanced modernity, have said little about climate change.

For practical purposes, it can no longer be assumed that nature is a stable, well understood, background constant and thus social scientists do not need direct knowledge about its changes. Any discussion of likely social, economic, and political futures will have to heed what natural scientists say about the likely impacts of climate change.

GROWING EVIDENCE OF GLOBAL WARMING

While originally eccentric, global warming was placed firmly on the agenda in 1985, at a conference in Austria of eighty-nine climate researchers participating as individuals from twenty-three countries. The researchers forecast substantial warming, unambiguously attributable to human activities.

Since that conference the researchers’ position has guided targeted empirical research, leading to supporting (and increasingly dire) evidence, resolving anomalies and winning near unanimous peer endorsement. Skeptics have been confounded and reduced to a handful, some discredited by revelations of dubious funding from fossil fuel industries.

Just before the end of the twentieth century, American researchers released ice-thickness data, gathered by nuclear submarines. The data showed that over the previous forty years the ice depth in all regions of the Arctic Ocean had declined by approximately 40 percent.

Five yearly aerial photographs show the ice cover on the Arctic Ocean at a record low, with a loss of 50 cubic kilometers annually and glacier retreat doubling to 12 kilometers a year. In September 2005 the National Aeronautics and Space Administration (NASA) doubled its estimates of the volume of melted fresh water flowing into the North Atlantic, reducing salinity and thus potentially threatening the conveyor that drives the Gulf Stream. Temperate mussels have been found in Arctic waters, and news broadcasts in 2005 and 2006 have repeatedly shown scenes of Inuit and polar bears (recently listed as endangered) cut off from their hunting grounds as the ice bridges melt.

In 2001 the Intergovernmental Panel on Climate Change (IPCC), the United Nation’s scientific panel on climate change, had predicted that Antarctica would not contribute significantly to sea level rise this century. The massive west Antarctic ice sheet was assumed to be stable. However, in June 2005 a British Antarctic survey reported measurements of the glaciers on this ice sheet shrinking. In October 2005 glaciologists reported that the edges of the Antarctic ice sheets were crumbling at an unprecedented rate and, in one area, glaciers were discharging ice three times faster than a decade earlier.

In 2005 an eight-year European study drilling Antarctic ice cores to measure the past composition of the atmosphere reported that CO₂ levels were at least 30 percent higher than at any time in the last 65,000 years. The speed of the rise in CO₂ was unprecedented, from 280 parts per million (ppm) before the Industrial Revolution to 388 ppm in 2006. Early in 2007 the Norwegian Polar Institute reported acceleration to a new level of 390 ppm. In January 2006 a British Antarctic survey, analyzing CO₂ in crevasse ice in the Antarctic Peninsula, found levels of CO₂ higher than at any time in the previous 800,000 years.

In April 2005 a NASA Goddard Institute oceanic study reported that the earth was holding on to more solar energy than it was emitting into space. The Institute’s director said: “This energy imbalance is the ‘smoking gun’ that we have been looking for” (Columbia 2005).

The second IPCC report in 1996 had predicted a maximum temperature rise of 3.5 degrees Fahrenheit by the end of the twenty-first century. The third report, in 2001, predicted a maximum rise of 5.8 degrees Fahrenheit by the end of the twenty-first century. In October 2006 Austrian glaciologists reported in Geophysical Research Letters (Kaser et al.) that almost all the world’s glaciers had been shrinking since the 1940s, and the shrinking rate had increased since 2001. None of the glaciers (contrary to skeptics) was growing. Melting glaciers could pose threats to the water supply of major South American cities and is already manifest in the appearance of many new lakes in Bhutan.

In January 2007 global average land and sea temperatures were the highest ever recorded for this month; in February 2007 the IPCC Fourth Report, expressing greater certainty and worse fears than the previous one, made headlines around the world. In 1995 few scientists believed the effects of global warming were already manifest, but by 2005 few scientists doubted it and in 2007 few politicians were willing to appear skeptical.

Although rising temperatures; melting tundra, ice and glaciers; droughts; extreme storms; stressed coral reefs; changing geographical range of plants, animals, and diseases; and sinking atolls may conceivably all be results of many temporary climate variations, their cumulative impact is hard to refute.

ANOMALIES AND REFUTATIONS

The science of global warming has progressed through tackling anomalies cited by skeptics. Critics of global warming made attempts to discredit the methodology of climatologist Michael Mann’s famous “Hockey stick” graph (first published in Nature in 1998). Mann’s graph showed average global temperatures over the last 1,000 years, with little variation for the first 900 and a sharp rise in the last century. After more than a dozen replication studies, some using different statistical techniques and different combinations of proxy records (indirect measures of past temperatures such as ice cores or tree rings), Mann’s results were vindicated. A report in 2006 by the U.S. National Academy of Sciences, National Research Council, supported much of Mann’s image of global warming history. “There is sufficient evidence from the tree rings, boreholes, retreating glaciers and other ‘proxies’ of past surface temperatures to say with a high level of confidence that the last few decades of the twentieth century were warmer than any comparable period for the last 400 years.” For periods before 1600, the 2006 report found there was not enough reliable data to be sure but the committee found the “Mann team’s conclusion that warming in the last few decades of the twentieth century was unprecedented over the last 1,000 years to be plausible” (National Academy of Science press release 2006).

Measurements from satellites and balloons in the lower troposphere have until recently indicated cooling, which contradicted measurements from the surface and the upper troposphere. In August 2005 a publication in Science of the findings of three independent studies described their measurements as “nails in the coffin” of the skeptics’ case. These showed that faulty data, which failed to allow for satellite drift, lay behind the apparent anomaly.

Another anomaly was that observed temperature rises were in fact less than the modelling of CO₂ impacts predicted. This is now explained by evidence on the temporary masking properties of aerosols, from rising pollution and a cyclical upward swing of volcanic eruptions since 1960.

Critics of global warming have been disarmed and discredited. Media investigations and social research have increasingly highlighted the industry funding of skeptics and their think tanks, and the political pressures on government scientists to keep silent. Estimates of the catastrophic costs of action on emissions have also been contradicted most dramatically by the British Stern Report in October 2006. Many companies have been abandoning the skeptical business coalitions. The Australian Business Round Table on Climate Change estimated in 2005 that the cost to gross domestic product of strong early action would be minimal and would create jobs.

SCIENTIFIC CONSENSUS

In May 2001 sixteen of the world’s national academies of science issued a statement, confirming that the IPCC should be seen as the world’s most reliable source of scientific information on climate change, endorsing its conclusions and stating that doubts about the conclusions were not justified.

In July 2005 the heads of eleven influential national science academies (from Brazil, Canada, China, France, Germany, India, Italy, Japan, Russia, the United Kingdom, and the United States) wrote to the G8 leaders warning that global climate change was “a clear and increasing threat” and that they must act immediately. They outlined strong and long-term evidence “from direct measurements of rising surface air temperatures and subsurface ocean temperatures and from phenomena such as increases in average global sea levels, retreating glaciers and changes to many physical and biological systems” (Joint Science Academies Statement 2005).

There are many unknowns regarding global warming, particularly those dependent on human choices; yet the consequences for society of either inadequate action or of any effective responses (through reduced consumption or enforced and subsidized technological change) will be huge. It is, for example, unlikely that the practices and values of free markets, individualism, diversity, and choice will not be significantly modified either by economic and political breakdowns or alternatively by the radical measures needed to preempt them.

INADEQUATE ACTION AND NEEDED TRANSFORMATIONS

Kyoto targets are at best a useful first step. However, even these targets, which seek to peg back emissions to 1990 levels by 2010, are unlikely to be met. World CO₂ emissions in 2004 continued to rise in all regions of the world, by another 4.5 percent, to a level 26 percent higher than in 1990. A rise of over 2 degrees is considered inevitable if CO₂ concentrations pass 400 ppm. At current growing emission rates, the concentration would reach 700 ppm by the end of the twenty-first century. The continuing industrialization of China, recently joined by India, points to the possibility of even faster rises than these projections indicate.

If unpredictable, amplifying feedback loops are triggered, improbable catastrophes become more likely. The Gulf Stream flow could be halted, freezing Britain and Northern Europe. Droughts could wipe out the agriculture of Africa and Australia, as well as Asia, where millions depend on Himalayan melt water and monsoon rains. If the ice caps melt completely over the next centuries, seas could rise by 7 meters, devastating all coastal cities. Will the human response to widespread ecological disasters give rise to solidarity and collective action, such as the aid that came after the 2004 Asian Tsunami or to social breakdowns, as seen in New Orleans after 2005’s Hurricane Katrina and in the Rwandan genocide?

Social and technical changes with the scale and speed required are not unprecedented. The displacement of horsepower by automobiles, for example, was meteoric. Production of vehicles in the United States increased from 8,000 in 1900 to nearly a million by 1912. Substantial regulation or differential taxation and subsidies would be indispensable to overcome short term profit motives and free riding dilemmas (where some evade their share of the cost of collective goods from which they benefit). Gains in auto efficiency in the 1980s, for example, were rapidly reversed by a new fashion for sport utility vehicles.

The debates that have emerged in the early twenty-first century have been related to responses, with different winners and losers, costs, benefits, dangers, and time scales for each response. Advocates of reduced energy consumption or increased efficiency, or energy generation by solar, wind, tidal, hydro, biomass, geothermal, nuclear, or clean coal and geo-sequestration, argue often cacophonously. Yet it seems probable that all these options are needed.

It will be essential for social and natural scientists to learn to cooperate in understanding and preempting the potentially catastrophic collision of nature and society. In order to accomplish this, market mechanisms; technological innovation; international, national, and local regulations; and cultural change will all be needed. Agents of change include governments, nongovernmental organizations, and public opinion, but the most likely front-runner might be sectors of capital seeking profit by retooling the energy and transport systems, while able to mobilize political enforcement.

SEE ALSODisaster Management; Greenhouse Effects; Science

BIBLIOGRAPHY

Columbia University Earth Institute. 2005. Press release 28, April. http://www.earthinstitute.columbia.edu/news/2005/story04-28-05.html.

Cooper, Richard N., and Richard Layard. 2002. What the Future Holds: Insights from Social Science. Cambridge MA: MIT Press.

Diamond, Jared. 2005. Collapse: How Societies Choose to Fail or Survive. Camberwell, U.K.: Penguin, Allen Lane.

Dunlap, Riley H., Frederick H. Buttel, Peter H. Dickens, and August Gijswijt, eds. 2002, Sociological Theory and the Environment: Classical Foundations, Contemporary Insights, Lanham, MD: Rowman and Littlefield.

Flannery, Tim. 2006. The Weather Makers. Berkeley, CA: Grove Atlantic.

Kaser, G., et al. Mass Balance of Glaciers and Ice Caps: Consensus Estimates for 1961–2004. Geophysical Research Letters, Vol. 33. 2006.

Legget, Jeremy. 2000. The Carbon War: Global Warming and the End of the Oil Era. New York: Routledge.

Leggett, Jeremy. 2005. Half Gone: Oil, Gas, Hot Air and the Global Energy Crisis. London: Portobello.

Monbiot, George. 2006. Heat: How to Stop the Planet Burning. London: Allen Lane.

National Academy of Sciences. 2006. Press release 22, June. http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=11676.

Stehr, Nico. 2001. Economy and Ecology in an Era of Knowledge-Base Economies. Current Sociology 49(1) January: 67–90.

Zillman, John W. 2005. Uncertainty in the Science of Climate Change. In Uncertainty and Climate Change: The Challenge for Policy, Policy Paper 3. Canberra: Academy of the Social Sciences in Australia. http://www.assa.edu.au/publications/op/op22005.pdf.

http://www.encyclopedia.com/topic/global_warming.aspx source