Global Warming: A Tale of Two Opposing Views

 

No wonder we’re all confused. When two different observers draw opposite conclusions from the same facts, it’s hard to know whom to believe.

This year marks the 30th anniversary of the testimony of NASA scientist James E. Hansen before the Senate Committee on Energy and Natural Resources in 1988. Hansen painted a dire picture of the future due to global warming and expressed his “high degree of confidence” in a “cause-and-effect relationship between the greenhouse effect and observed warming.”

Hansen laid out three possible scenarios for the future:

  • Scenario A – called “business as usual” – assumed the accelerating emissions growth typical of the 1970s and ‘80s. He predicted the earth would warm 1 degree Celsius by 2018.
  • Scenario B – set emissions lower, rising at the same rate today as in 1988. He called this outcome the “most plausible” and predicted it would lead to about 0.7 degree of warming by 2018.
  • Scenario C – set constant emissions beginning in 2000 – which he deemed “highly unlikely” – and predicted temperatures would rise a few tenths of a degree before flatlining after 2000.

 

These are the facts from his testimony in 1988. How did things turn out 30 years later? Which Scenario actually happened? Depends upon whom you read.

Patrick J. Michaels and Ryan Maue of The Cato Institute write their opinions in The Wall Street Journal. They say the winner is Scenario C. Global surface temperature has not increased significantly since 2000,(emphasis mine) discounting the larger-than-usual El Nino of 2015-16. Assessed by Mr. Hansen’s model, surface temperatures are behaving as if we had capped 18 years ago the carbon-dioxide emission responsible for the enhanced greenhouse effect. But we didn’t. And it isn’t just Mr. Hansen who got it wrong. Models devised by the United Nations Intergovernmental Panel on Climate Change have, on average, predicted about twice as much warming as has been observed since global satellite temperature monitoring began 40 years ago.”

They say Hansen was also wrong about his claims that hurricanes would get stronger and they would cause increasing amounts of damage. He said tornadoes would also get stronger but they say National Oceanic Atmospheric Administration (NOAA) data suggests the opposite.

In a 2007 case on auto emissions, Hansen testified that most of Greenland’s ice would soon melt, raising sea levels 23 feet over the course of 100 years. Michaels and Maue say, “Subsequent research published in Nature magazine on the history of Greenland’s ice cap demonstrated this to be impossible. Much of Greenland’s surface melts every summer; meaning rapid melting might reasonably be expected to occur in a dramatically warming world. But not in the one we live in. The Nature study found only modest ice loss after 6,000 years of much warmer temperatures than human activity could ever sustain.

On the other hand, Seth Borenstein, writing for The Associated Press, claims an entirely different interpretation of the data. He says, “Thirty years later, it’s clear that Hansen and other doomsayers were right. Earth is noticeably hotter, the weather stormier and more extreme. Polar regions have lost billions of tons of ice; sea levels have been raised by trillion of gallons of water. Far more wildfires rage.”

Borenstein claims the world’s annual temperature has warmed nearly 1 degree and the temperature in the U.S. has gone up even more – nearly 1.6 degrees.

Two totally different points of view from observations of the same data.

What are the backgrounds of these different writers?

Seth Borenstein is a journalism professor for New York University and a science writer for The Associated Press.

Patrick J. Michaels has a PhD in ecological climatology from The University of Wisconsin – Madison. His doctoral thesis was entitled Atmospheric anomalies and crop yields in North America. He is a senior fellow in environmental studies at The Cato Institute.

Ryan Maue has a PhD in meteorology from Florida State University and was awarded a National Research Council postdoctoral associateship at the Naval Research Lab in Monterey, California where he focused on global weather prediction and verification. He is also a research meteorologist and adjunct scholar at the Cato Institute.

Who is correct? Their scientific credentials should help you decide.

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