A Canadian researcher’s assertion that carbon dioxide emissions are not the primary cause of global warming has been met by his peers with skepticism and even ridicule, proving how politically fraught the climate change debate can be within Canada’s science community.
In a controversial new study, University of Waterloo physics professor Qing-Bin Lu contends that the world has actually been cooling in the years since governments clamped down on aerosol gasses, which he believes are the real culprit for climate change.
“Conventional thinking says that the emission of human-made non-CFC (chlorofluorocarbon) gases such as carbon dioxide has mainly contributed to global warming,” Lu said.
“But we have observed data going back to the Industrial Revolution that convincingly shows that conventional understanding is wrong,” he said in a press release drawing attention to his study, published in the little-known International Journal of Modern Physics B.
Lu’s report challenges the widely held notion that carbon dioxide emissions are the main cause of human-driven climate change and instead suggests that CFCs have been to blame for a trend of anthropogenic global warming from 1970 to about 2002.
CFCs were banned in the 1987 Montreal Protocol after they were found to be the major cause for a giant hole in Earth’s ozone layer, which is expected to recover by 2050 if the responsible substances remain controlled.
Lu’s findings, based on statistical analysis that found a correlation between the rise of CFC emissions and temperature, suggest that the world may not be headed for climate catastrophe caused by carbon dioxide.
The study immediately met with skepticism and backlash from scientists and news reports that highlighted the oppositional nature of Lu’s findings, with headlines such as “CFC warming theory challenged” and “No, CFCs are almost certainly not causing all of global warming.”
In a Postmedia News article titled “Climate change claims raise eyebrows,” a number of Canadian climate experts, some of whom acknowledged that they had not read the study, expressed disappointment that Lu’s views appear to fly in the face of decades of scientific thinking.
Meanwhile, an editorial in Postmedia’s conservative-leaning The Province, proclaimed that the report is part of a wave of challenges to conventional thinking that should remind “panicky governments they should stop letting their brains be fried by professional alarmists ... and keep a cool head.”
That a single scientific report raises such strong emotions from scientists and media indicates just how politically charged the topic of climate change has become, and some scientists are concerned that one contrarian view could steal the spotlight from the consensus of hundreds of scientists. Others fear that any scientific paper emphasizing the uncertain nature of climate change could be used by naysayers as an excuse to do nothing or undermine efforts to make changes to reduce greenhouse gases.
Scientists, many of whom are used to insular academic debate, have been thrust into the middle of one of the hottest political battles of our time, said Douglas MacDonald, senior lecturer at the University of Toronto’s School of Environment.
“For whatever reason, climate change is one of the most politically charged issues that we’ve got right now.”
Lu’s paper is just the latest to stoke the fires of debate in a scientific community that has fought for years to make their consensus that climate change is real and caused by human activity an accepted global principle.
The physicist, not widely known among climate scientists, has proposed theories in the past that have been challenged in the community.
But Lu takes issue with that criticism, saying not only were attempts to debunk his theory misguided, but that his latest paper provides "more solid and convincing evidence" than previous papers on CFCs and the ozone layer.
Lu said the scientists, Groob and Mueller, who rebutted his work did not use the same data he used (from a Canadian satellite that measures the Earth's atmosphere) and later had to make a correction.
He dismissed their research in his latest paper, which passed muster with two reviewers, saying "their criticisms cannot stand from the scientific facts in the literature."
"In this distorting climate research community, people could use obviously fabricated (non-existing) data to debunk a paper presenting solid and convincing comprehensive datasets. And they even got praises in the public media" Lu told HuffPost.
"This is why the climate 'science' has been so controversial."
In his most recent paper, Lu takes issue with the common view that global temperatures will continue to rise along with an increase in CO2 levels. According to his analysis, global temperatures have actually been declining since 2002, matching a decline in CFCs in the atmosphere. He further believes that the cooling trend will continue for the next 50 to 70 years as the amount of CFCs in the atmosphere continues to drop.
Lu is quick to point out he is not denying that other human activities have caused Earth to heat up, but is suggesting that the major culprit has been conquered, so the emphasis on carbon dioxide is misplaced.
“We did have about 0.6 per cent [temperature] increase from 1970 to 2002, I think it’s very well documented, and from the data I have seen, this was indeed the age of human activity, and namely because of CFCs, the data are telling me.”
He believes the paper will change some attitudes and lead some to reconsider the role of carbon dioxide in a debate that he believes has become too politicized.
“People working in the mainstream CO2 sphere, they try to ignore this new discovery. However there’s quite a number of scientists in the world … we know that global warming is very unlikely due to CO2.”
Gordon McBean, a director at the Centre for Environment and Sustainability at Western University, dismissed Lu’s findings, saying that while they illustrate some correlations, they merely imply causation without showing a physical connection between the two events, an error that is considered a basic aspect of flawed science.
“Sure CFCs are a greenhouse gas. We’ve always understood that, but to argue that CO2 is not causing anything, based on a correlation, ... is irrelevant.”
Using data from 1850 to 1970, an era before there were any significant CFC emissions, Lu found that while CO2 levels rose as a result of the Industrial Revolution, there was no accompanying rise in global temperatures, excluding the solar effect.
“The conventional warming model of CO2, suggests the temperatures should have risen by 0.6°C over the same period, similar to the period of 1970-2002,” Lu said.
But McBean said “no credible climate scientist would claim there should be a correlation” between CO2 and global warming during that time.
The scientific community has studied the impact of CFCs in the past, he said, but the definitive 2007 paper from the Intergovernmental Panel on Climate Change, as well as many other scientific reports, highlight carbon dioxide as the major cause.
‘’We’re now expected to throw all this out on the basis of one paper published by a guy none of us have heard of?” he asked.
McBean is concerned that a study such as Lu’s could provide fodder to governments disinclined to act on climate change and allow officials and leaders to ignore the emissions of oilsands, coal and other sources of CO2 emissions.
“Unfortunately, certain governments and certain organizations will be quite happy to see these kind of scientific results and will use them quite often out of context to argue a policy case for which there really shouldn't be that kind of analysis.”
But MacDonald at UofT believes climate change has evolved as a political issue to the point that debate is no longer about whether the science is strong enough to support action – few governments publicly deny that climate change is real – but about how governments can afford to deal with the issue and whether there is political will from citizens.
“What’s preventing effective policy now isn’t really doubts about the empirical validity of the problem and what to do about it, it’s this larger and more difficult issue of bringing about social change on this kind of a scale.”
John Stone, a lead author at the IPCC, said he was “somewhat surprised” by the suggestions in Lu’s abstract. He said it is important not to overemphasize the findings of one report contradicting many that have found the impact of CFCs to be slight compared with that of carbon dioxide.
He also took issue with Lu’s conclusion that Earth has been cooling since 2002, saying Lu did not adjust for natural occurrences as other scientists have.
Despite a relatively stable decade of global temperatures, “the overall long-term trend is going up,” he said.
Still, he concedes that the report, as any in the scientific community, is worthy of further study.
“It’s open to challenge, and that’s good, because that’s the only way science will advance. So this, presumably, will be looked at very carefully, and other scientists will comment, and through that process we’ll eventually figure out just what the truth is.”
CLARIFICATION: After this article was published, Prof. Lu took issue with the reference to his prior articles being "debunked" by climate scientists and the refererence has been changed to indicate those scientists have "challenged" his work. This version has been updated.