Story summary: climate experts have rejected a study challenging the established science showing that climate change is due to human interference. The study, partly funded by the American petroleum Institute, was undertaken by a group of scientists including two arch climate sceptics with strong links to the fossil fuel industry, including ExxonMobil.

The work has been widely promoted by the front groups paid by Esso/ExxonMobil.

Full article

A team of climate experts has rejected as invalid an industry-linked study which argued that the Earth's rising temperature may not be the result of human activity.

The study, authored by five scientists, including two from the Harvard-Smithsonian Astrophysical Observatory, asserted that the Earth experienced a warming trend in the Middle Ages that was even more dramatic than the current trend.

The occurrence of such a climate anomaly at a time before widespread combustion of coal, oil and natural gas began would raise questions about the scientific belief that current warming can be explained only by carbon dioxide given off by the combustion of these fossil fuels.

But in a paper appearing this week in EOS, a scientific journal published by the American Geophysical Union, 13 scientists reaffirmed their own earlier conclusions that a rise in the Earth's temperatures beginning in the late 20th century is unprecedented in at least 1,000 years.

There is a "robust consensus" among scientists that the current warming is caused by human activities, said authors of the EOS paper. The EOS paper was written specifically to respond to the earlier study, which has been widely promoted by industry representatives, nonprofit organizations and politicians who oppose government actions aimed at controlling so-called "greenhouse gases."

Authors of the earlier study said they reexamined data cited in more than 200 scientific studies during the past decade and found evidence supporting the contention that the Earth heated up dramatically between 800 and 1300 AD.

Astronomers Willie Soon and Sallie Baliunas of the Harvard-Smithsonian center appear as authors of two papers based on the study. Neither responded to telephone messages requesting response to the EOS paper.

Cox Newspapers, in an article published in May, disclosed that the study by Soon, Baliunas and three other authors was underwritten by the American Petroleum Institute and promoted by nonprofit groups that are funded by energy interests, chiefly ExxonMobil Corp.

In addition, some of the five authors have received funding from energy interests or nonprofits supported by energy interests. The EOS response stated that Soon, Baliunas and their co-authors failed to show statistical evidence of an earlier, worldwide warming period, presenting merely anecdotal evidence of local warming trends.

Authors of the EOS article include many of the scientists whose data Soon, Baliunas and their co-authors claimed to have re-examined. The Soon-Baliunas study continues to be cited by opponents of government action to address the global warming issue. The White House edited a draft Environmental Protection Agency "State of the Environment" report to remove statements that the Earth is growing warmer and replace them with material from the two papers.

The final version of the report leaves out both references to global warming. The 13 authors of the EOS paper are: Michael Mann of the University of Virginia; Caspar Amman, Kevin Trenberth and Tom Wigley of the National Center for Atmospheric Research in Boulder, Colo.; Ray Bradley of the University of Massachusetts; Keith Briffa, Philip Jones and Tim Osborn of the University of East Anglia, Norwich, England; Tom Crowley of Duke University; Malcolm Hughes and Jonathan Overpeck of the University of Arizona; Michael Oppenheimer of Princeton University, and Scott Rutherford of the University of Rhode Island.

[Previous article: "Alaska warms up"]
[Next article: "Global warming is now a WMD"]