According to a new report released by the Intergovernmental Panel on Climate Change (IPCC), the world’s leading climate scientists believe that global warming is “very likely” caused by man, specifically man’s burning of fossil fuels. This includes vehicle emissions of carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, and sulfur hexafluoride. “Climate Change 2007” is the first assessment of climate change released by the IPCC since 2001, and transcends all previous warnings on the consequences of global warming.

The phrase “very likely” translates to a more than 90 percent certainty that global warming is caused by man. The report states that, “the observed widespread warming of the atmosphere and ocean, together with ice-mass loss, support the conclusion that it is extremely unlikely that global climate change of the past 50 years can be explained without external forcing, and very likely that it is not due to known natural causes alone.”

Global Fossil Carbon Emissions since 1800

A new report released by the Intergovernmental Panel on Climate Change (IPCC) states that global climate change of the past fifty years is not due to natural causes alone. The figure shows significant increases in global fossil carbon emissions since 1850. Credit: Carbon Dioxide Information Analysis Center (CDIAC),

The report predicts a 3.2–7.2 degree Fahrenheit increase in temperature by 2100, as well as a 7–23 inch rise in sea level by the end of the century. Despite the already dismal outlook on the effects of global warming, many climate scientists believe the report is too “sugarcoated” and that the actual rise in sea level could exceed 55 inches. The report excludes recent ice sheet melting in Greenland and Antarctica, that if continues, could drastically elevate sea levels sooner, and more severely, than most anticipated. A prediction excluding the melting activity in these two areas is “obviously not the full story because ice sheet decay is something we cannot model right now, but we know it’s happening,” said Stefan Rahmstorf, a climate panel lead author from Germany. Currently, the report only considers glacier decay in its calculations. It was suggested that the report contain some sort of disclaimer saying that if ice sheets continue to melt, the rise in sea level could be far worse.

Aside from some contention over rising sea level predictions, many consider the IPCC’s assessment reports to be the most accurate take on climate change worldwide. Most likely, the opinion is based on the IPCC’s consensus-building structure. For example, in order to produce “Climate Change 2007,” the IPCC unified over 2,500 scientific expert reviewers and more than 1,250 contributing and lead authors from more than 130 countries. IPCC reports must be unanimous and approved by all governments involved, including the Unites States and oil-rich countries such as Saudi Arabia.

“Climate Change 2007,” which is more than one thousand pages long, will be published in four volumes. Working Group I tackled the first volume of the report, “Climate Change 2007: The Physical Science Basis,” which evaluates “the current scientific knowledge of the natural and human drivers of climate change, observed changes in climate, the ability of science to attribute changes to different causes, and projections for future climate change,” an IPCC press release said.

Working Group II will assess the impacts, adaptation, and vulnerability associated with global warming, and Working Group III will look into mitigation options. These volumes will be finalized respectively in early April and early May. A Synthesis Report covering the crucial findings of all three Working Groups will be published in late 2007.

IPCC was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP). For more information on “Climate Change 2007” and the IPCC, please visit the IPCC Web site (

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