Difference between revisions of "Global warming"

Revision as of 00:35, May 22, 2007

Global warming is the term ascribed to an increase in the global mean temperature. Average Earth surface air temperature has risen just over one degree since 1850. ^[1]

Assessments by the United Nations promote the world view that most of the warming since around 1850 is mostly human-caused. In February, 2007, the Intergovernmental Panel on Climate Change, a body of scientists^[2] established by the United Nations, released their fourth assessment report on climate change. That report concluded that most of recent global warming was "very likely" caused by human activity^[3]. It says that increases in atmospheric concentrations of greenhouse gases cause warming.

There have been many cycles of naturally-caused global warming and cooling over many millions of years (see climate cycles). Some scientists, including Richard Lindzen of MIT, Sallie Baliunas of Harvard and Fred Singer (independent), say that the recent warming could be part of another natural cycle.

The Hockey Stick Reconstruction

One of the main arguments for anthropogenic global warming during the 3rd IPCC report was a temperature reconstruction done by climatologist Michael Mann. The resulting graph of the Northern Hemisphere temperature is shaped like a hockey stick, and it is used as evidence for the unusualness of the earth's temperature in the past few decades. However, Stephen McIntyre and economist Ross McKitrick later discovered a serious flaw in the statistical methods used to construct the hockey stick graph. Because of this, the 4th Assessment Report of the IPCC included several different temperature reconstruction methods instead of favoring just one hypothesis.

Natural variability of the climate system

Evolutionary scientists who believe in global warming think that the Earth has experienced numerous ice ages over two million years, during which global temperatures dropped approximately 6 degrees Celsius and then returned to normal. The frigid temperatures allowed ice sheets to expand southward, covering much of Asia, Europe, and North America. The cooling associated with ice ages is gradual, while the terminations are relatively rapid. However, even the rapid terminations of ice ages take centuries to millennia.

Global Warming on other Planets

Since the Viking spacecraft reached Mars in the 1970s until recent readings were taken, the average temperature on Mars has risen 1.1 degrees Fahrenheit just as the average temperature on the earth has risen. Since human industrialization is clearly not to blame for the change on Mars, other causes are being considered. One possibility is that dust storms are changing the albedo of the planet, allowing it to warm, while another possibility is that solar variations from the sun are causing the warming.^[4][5]

Recently, it has also been found that similar to the Earth and Mars, Neptune is also undergoing global warming. Measurements taken at the Lowell observatory in Arizona have shown an increase in Neptune's brightness and temperature since 1980 following the same pattern seen on Earth and Mars. The researchers who discovered this warming suggest there may be a correlation between the warming and solar variations.^[6]

Pluto has also been found to be undergoing global warming.^[7]

Politics of global warming

The global average surface temperature warmed about 0.5 °C (0.9 °F) over the second half of the 20th Century, and to some the warming appears to be related to increases in carbon dioxide and other greenhouse gases. The possibility of adverse consequences has become a major concern for environmentalists.

Assessments of climate science by the United Nations (see IPCC - Intergovernmental Panel on Climate Change) have claimed that scientists are 90% sure that over 50% of the observed global warming in recent decades is human-caused, and that continued global warming should be expected over at least the next century. Science published a literature search by Naomi Oreskes concluding that "scientific consensus" supports the IPCC reports. ^[8]

Several prominent scientists have pointed out the politicized science of the UN's assessment methods. The scientific reports are submitted to a panel of representatives appointed by each country in the IPCC. Several scientists whose research demonstrates that climate change is taking place have complained about their work being misrepresented by the U.N.

58% of the 279 climate scientists working at US federal agences who responded to a survey by The Union of Concerned Scientists reported 435 incidents of political interference over the past five years^[9] and that they had experienced at least one of these constraints:

• “Pressure to eliminate the words ‘climate change,’ ‘global warming’, or other similar terms” from their communications.
• Editing of scientific reports by their superiors which “changed the meaning of scientific findings”.
• Statements by officials at their agencies which misrepresented their findings.
• “The disappearance or unusual delay of websites, reports, or other science-based materials relating to climate”.
• “New or unusual administrative requirements that impair climate-related work”.
• “Situations in which scientists have actively objected to, resigned from, or removed themselves from a project because of pressure to change scientific findings.”

However, those who believe that either global warming is not a real phenomenon or that humanity's contribution to it has been overstated have made similar complaints. The UCS states in its report about the IPCC ^[10]

Climate contrarians frequently claim that the IPCC produces politically motivated reports that show only one side of the issues. Given the many stages at which experts from across the political and scientific spectrum are included in the process, however, this is a difficult position to defend.

Furthermore, according to IPCC principles, lead authors are “required to record views in the text which are scientifically or technically valid, even if they cannot be reconciled with a consensus view.”

There is widely held belief among the American public that global warming is a reality. A poll conducted March 11-14 of 2007 found that the majority of the American public (59%) believes we are already seeing the effects of global warming, an additional 3% and 8% respectively believe they will see the effects with in a few years or within their lifetime, and 19% believe that global warming will be seen, not in their lifetime, but in future generations—only a small minority (8%) believe that global warming will never happen. ^[11].

Scientists

Roger Revelle

See Also

• Does a global temperature exist?, Journal of Non-Equilibrium Thermodynamics, June 2007.
• The appliance of science by Mike Hulme.
• An Inconvenient Truth, Film by Al Gore
• The Great Global Warming Swindle - Documentary Film
• Climate Sensitivity and Observed Negative Feedbacks, lecture by Richard Lindzen and Roberto Rondanelli.
• Nature of Arguments for Anthropogenic Global Warming, by Richard Lindzen
• Hot Talk, Cold Science: Global Warmings's Unfinished Debate, by S. Fred Singer
• Global Warming: The Origin and Nature of the Alleged Scientific Consensus - Richard S. Lindzen, Alfred P. Sloan Professor of Meteorology at the Massachusetts Institute of Technology
• "Should We Have Acted Thirty Years Ago to Prevent Climate Change?", by Randall G. Holcombe.
• "After Kyoto: A Global Scramble for Advantage," by Bruce Yandle.
• Global warming smear targets
• The physical evidence of earth's unstoppable 1,500-year climate cycle
• "Is There a Basis for Global Warming Alarm?", by Richard Lindzen
• "New Perspectives in Climate Change: What the EPA Isn’t Telling Us"
• Survey Shows Climatologists Are Split on Global Warming
• Fighting the Hoax

Critique of the Hokey Stick Reconstruction

• The Decay of the Hockey Stick by Von Storch published on the journal Nature's blog, May 3, 2007.
• A Global Warming Bombshell by Richard A. Muller, Technology Review , Oct. 2004; calls into question famous graph by Michael Mann
• Reconstructing Past Climate from Noisy Data by Hans von Storch, Eduardo Zorita, Julie M. Jones, Yegor Dimitriev, Fidel González-Rouco, Simon F. B. Tett, Science magazine, 22 October 2004.

References

1. ↑ Hansen's group at the Goddard Institute wrote, "Global warming is now 0.6 °C [1.0 °F] in the past three decades and 0.8 °C [1.4 °F]in the past century." http://data.giss.nasa.gov/gistemp/2005/
2. ↑ http://www.chicagotribune.com/news/nationworld/chi-0704280477apr29,1,4275902.story?coll=chi-newsnationworld-hed
3. ↑ http://news.bbc.co.uk/2/hi/science/nature/6321351.stm
4. ↑ http://www.space.com/scienceastronomy/070404_gw_mars.html
5. ↑ http://www.heartland.org/Article.cfm?artId=17977
6. ↑ http://www.agu.org/pubs/crossref/2007.../2006GL028764.shtml
7. ↑ http://www.space.com/scienceastronomy/pluto_warming_021009.html
8. ↑ http://www.sciencemag.org/cgi/content/full/306/5702/1686]
9. ↑ Union of Concerned Scientists and Government Accountability Project, February 2007. Atmosphere of Pressure: Political Interference in Federal Climate Science. http://www.ucsusa.org/assets/documents/scientific_integrity/Atmosphere-of-Pressure.pdf
10. ↑ http://www.ucsusa.org/global_warming/science/the-ipcc.html
11. ↑ Poling report on Gallup poll for March 11-14, 2007[1]