“No Need to Panic About Global Warming“, was the headline over an opinion article in the Wall Street Journal by 16 scientists who dismiss fears of widespread damage from climate change.

Many mainstream experts, looking at data like the graph above showing a long-term warming trend, have rejected the Jan. 26 article as a mish-mash of wishful thinking and exaggerations by scientists who are not in touch with the numbers. Others, like Republican Presidential hopeful Rick Santorum, have a more extreme view of “truth” and dismiss global warming as a “hoax”.

So where do well-informed scientists who doubt global warming is happening get their data from? This is an attempt to find out.

Wall Street Journal: “Perhaps the most inconvenient fact is the lack of global warming for well over 10 years now.”

According to the World Meteorological Organization (WMO), the 13 warmest years since records began in the mid-19th century have all occurred in the 15 years since 1997 – making it hard to conclude that warming has stopped. The warmest years were 2010, 2005 and 1998.

The assertion in the WSJ seems to be based on the observation that 1998 was the warmest year and so global warming has stopped. But the logic does not really hold up: temperatures of 1998 were driven up by natural variations — an exceptionally strong El Nino event in the Pacific that can nudge up temperatures worldwide and is a far bigger effect than the year-to-year buildup of greenhouse gases. And mainstream climate scientists say it is unreasonable to assume that temperatures will rise steadily year by year.

Here is one WMO graph of temperatures — sceptics look at the spike in 1998 and say it’s stopped since then. Mainstream scientists look at the longer term upwards trend over decades.

VERDICT ON WSJ STATEMENT: UNTRUE

But there are exaggerations in the mainstream too.

“Our science is solid and it proves unequivocally that the world is warming and that this warming is due to human activities,” Michel Jarraud, Secretary-General of the WMO, said in a written statement about temperatures in 2011.

But his assertion that science proves that warming is due to human activities goes well beyond the findings by the main U.N. authority, the Intergovernmental Panel on Climate Change (IPCC), in its last report in 2007.

That says that: “Warming of the climate system is unequivocal” (i.e. the world is getting warmer but it might be due to natural variations). It separately says it is at least 90 percent likely that human activities are “the main cause of warming in the past 50 years.” So there’s a small chance that natural variations – solar activity, etc – might be causing most recent warming, i.e. there is no proof.

Wall Street Journal: “Although the number of publicly dissenting scientists is growing, many young scientists furtively say that while they also have serious doubts about the global-warming message, they are afraid to speak up for fear of not being promoted—or worse.”

VERDICT – NO EVIDENCE, VERY PROBABLY UNTRUE

The article gives no numbers for “dissent” and many mainstream scientists say it is absurd to suggest that there is a conspiracy to cover over a lack of evidence for global warming. Richard Alley, an IPCC author at the University of Pennsylvania, notes that Einstein became famous for exposing shortcomings in Newton’s theory of gravity: i.e. it is every scientist’s dream to show where well-established theories are wrong.

Wall Street Journal article: “Even if one accepts the inflated climate forecasts of the IPCC, aggressive greenhouse-gas control policies are not justified economically. A recent study of a wide variety of policy options by Yale economist William Nordhaus showed that nearly the highest benefit-to-cost ratio is achieved for a policy that allows 50 more years of economic growth unimpeded by greenhouse gas controls.

Nordhaus told Andrew Revkin’s Dot Earth blog in the New York Times:

“The piece completely misrepresented my work. My work has long taken the view that policies to slow global warming would have net economic benefits, in the trillion of dollars of present value. And the IPCC said that the cost of limiting global warming in the most aggressive scenario it considered, would brake world GDP by less than 3 percent by 2030.

VERDICT – UNTRUE

What’s politics or science? There is a clear Republican-Democrat divide about what is true or false.

“We have seen the politicization of science like we have never seen it before…We saw it with global warming…I for one never bought the hoax,” – Republican Presidential candidate Rick Santorum, February 2012

 “Climate change poses a grave and growing danger to our people…This is not fiction, it is science.  Unchecked, climate change will pose unacceptable risks to our security, our economies, and our planet,” President Barack Obama, Copenhagen summit, 2009.