The bet that two Durangoans made on whether the Earth’s overall temperature would be hotter or colder in 2017 than in 2007 – this year marks the halfway point – has been lost amid global controversy about the issue among scientists and others.

Let’s recall: A world conference last year in South Africa aimed at doing something to reverse climate change ended with little but high hopes. In 2009, hacked email exchanges that allegedly showed pro-global warming scientists had fudged their data stirred global debate.

T hose events hadn’t occurred in January 2008 when Roger Cohen, a global-warming skeptic and retired manager of strategic planning at Exxon Mobil, threw down the gauntlet.

Cohen, fed up with doomsday predictions about the environmental disaster awaiting from burning fossil fuels, was sure enough to bet $5,000 that the Earth would be cooler in 2017 than in 2007. Dr. Richard Grossman, who practices gynecology and obstetrics, met the challenge. They will abide by the findings of HadCRUT3 (Hadley Centre and University of East Anglia Climatic Research Unit) in England.

Their $10,000 was deposited with the Community Foundation of Southwest Colorado to benefit Durango Nature Studies.

So neither will ultimately gain financially, but the bigger stakes – who’s right – are on the line. Halfway through the bet, both remained convinced they’re on the winning side.

“I don’t know if they can prove all warming is from anthropogenic (human) causes,” Grossman said. “But it’s getting warmer.”

Melting glaciers, vanishing sea ice and rising ocean levels support findings of global warming, Grossman said.

Cohen said a very small degree of warming could be attributed to human activity, but he supports data that finds temperature readings have been flat for more than a decade.

Changes in temperature, the amount of sea ice, ocean levels and glacier size have occurred in other periods, he said.

Since Cohen and Grossman bet, opinions worldwide have become more polarized. Supporters of global warming say evidence is incontrovertible and that the real issue is to find policies to reverse the trend. Deniers say the evidence is unreliable, inconsistent or manipulated. Unless people dig into the science themselves, they have to turn to professionals for opinions about what’s happening to the Earth’s temperature.

Among the opinions

National Oceanic and Atmospheric Administration: 2011 tied 1997 as the 11th-warmest year since records began in 1880 and marked the 35th consecutive year that the global temperature was above the 20th-century average.

National Aeronautic Space Administration: 2011 was the ninth-warmest since 1880, continuing a trend in which nine of the 10 warmest years in the modern meteorological record have occurred since 2000. The warmest years were 2005 and 2010.

The independent Berkeley Earth Surface Temperature Project warned against basing trends on periods of 13 to 15 years: Some people draw a line covering 1998 to 2010 and argue that’s confirmation of no temperature change. If you did that same exercise in 1995 and drew a line through the data from 1980 to 1995, you might have falsely concluded that global warming had stopped back then.

United Nations World Meteorological Organization: Thirteen of the warmest years recorded have occurred in the last 15 years.

Among the naysayers

The Daily Mail in England: The supposed consensus on manmade global warming is facing an inconvenient challenge after the release of new temperature data showing the planet has not warmed for the last 15 years. The figures suggest that we could even be heading for a mini-ice age to rival the 70-year temperature drop that saw frost fairs held on the Thames Rivers in the 17th century.

Based on data from 30,000 measuring stations, the data was issued last week by the Met Office and the Unversity of East Anglia Climatic Research Unit.

A Wall Street Journal op-ed piece on Friday with 16 signators said “drastic actions” on global warming is not needed. Among the panel’s assertions: Carbon dioxide is not a pollutant; there’s been no global warming for more than a decade; young scientists fear to dissent from the majority opinion on global warming; the pro-warming contingent is hijacking science in the manner of Soviets of another era.

Media Matters for America wasted no time in answering. The Web-based nonprofit founded in 2004, which has 80 to 90 researchers, says its mission is “comprehensive monitoring, analyzing and correcting conservative misinformation in the U.S. media.”

Research shows that among the 16 experts who signed the op-ed piece are a physician, a retired airplane designer and a retired electrical engineer, Media Matters says. Only four have published peer-reviewed research related to climate change and six, including Cohen, have been linked to fossil-fuel interests,

Media Matters likens the experts to vocal minorities who dismiss the risk of secondhand smoke, deny the link between HIV and AIDS, and blame vaccines for an increase in reported cases of autism.

Grossman and Cohen wait and watch as data rolls in, and really, it’ll be a few years before it truly counts. The wager compares the average global temperature of 2005-07 with the average global temperature of 2015-17.

“If we compared the average temperature of 2005-2007 with 2009-2011, I’d win by a hair,” Cohen said. “But the bet is not about winning or losing, but about bragging rights.”

When reckoning is done in 2018 to settle the bet, the only winner could be Durango Nature Studies.

Lon Irwin, director of the Community Foundation, said Tuesday that, barring another 2008-type economic washout, the $10,000 deposited in 2008 may grow to $12,000 to $13,000.

daler@durangoherald.com