Trump's choice to head the EPA, Scott Pruitt, has been widely maligned in the media as a “prominent denier of climate science.”  This portrayal of Mr. Pruitt, however, isn't justified. What Pruitt actually said was far less offensive than “I deny science.” Rather, as voiced in his op-ed, he merely stated that, “Healthy debate is the lifeblood of American democracy, and global warming has inspired one of the major policy debates of our time. That debate is far from settled. Scientists continue to disagree about the degree and extent of global warming and its connection to the actions of mankind. That debate should be encouraged.”  This isn't a denial of science. It's an acceptance that much ambiguity exists within the scientific research and has for quite some time.
To start, let's review the lack of historical consistency. In a 1950 article entitled “Is the World Getting Warmer,” we were warned of global warming, stating “In the United States, long-term climatological records which have been accumulating over many years indicate that the weather is becoming warmer and drier.”  But in 1958, geophysicist Maurice Ewing and geologist William Donn warned of a coming ice-age, rather than an age of increased warming.   In 1965, an environmental report written by the President's Science Advisory Committee flipped the script again, warning President Johnson about global warming, rather than of a coming ice-age, advising “an increase of atmospheric carbon dioxide could act, much like the glass in a greenhouse, to raise the temperature of the lower air.”  But in 1970, a Washington Post's article entitled “Colder Winters Held Dawn of New Ice Age – Scientists See Ice Age In the Future” again went back to warning the public of a coming ice-age  and in 1972, geologists George J. Kukla and R. K. Matthews wrote to President Nixon also warning of the supposed “new ice age.”  In 1974, Time magazine released an article on global COOLING, advising that “when meteorologists take an average of temperatures around the globe, they find that the atmosphere has been growing gradually cooler for the past three decades.”  In 1975, the New York Times also released an article on global cooling, citing a scientific study from the National Academy of Sciences which warned of “an abrupt end to the present interglacial period of relative warmth that has governed the planet's climate for the past 10,000 years.” 
In 1976, however, the tone began to flip back towards warming, with scientists concluding, “The data are scanty. We cannot be sure that these temperature fluctuations are be not the result of natural causes. [but] ...Because of the rapid diffusion of CO2 molecules within the atmosphere, both hemispheres will be subject to warming due to the atmospheric (greenhouse) effect...”  And by 1979, after studying early computer models, the somewhat stronger case for global warming appeared to solidify in a report entitled “Carbon Dioxide and Climate: A scientific Assessment,” which warned of the socioeconomic impacts of global warming. 
Then a major scientific controversy occurred. In 1998, climatologist Michael E. Mann (along with others) developed new statistical models to produce global temperature patterns, creating a now infamous graph known as “the hockey stick graph.”  It was dubbed “hockey stick” because the line representing temperature was relatively perpendicular through most of the graph until it spiked straight up at the far right end, projecting large and sudden temperature increases in the near future.  This finding supposedly ended all debate and cemented cause for concern. It was widely circulated, widely cited, referenced as the basis for Al Gore's Oscar winning film “An Inconvenient Truth,” and used to foment fear and stir up support for drastic regulations. Many years later, however, it was thoroughly and widely discredited.  Mann had used a controversial subset of tree ring records from high and arid mountains in the US Southwest. ...The scientists who published that original data (Graybill and Idso 1993) had specifically warned that the ring widths should not be used for temperature reconstruction, and in particular warned that their 20th century portion is unlike the climatic history of the region and is probably biased by other factors.”  Never the less, Mann used this data and, in addition, “exaggerated the significance of the bristlecones so as to make their chronology out to be the dominant global climatic pattern rather than a minor (and likely inaccurate) regional one.”  His method also appeared to remove the “medieval warm period” which previously suggested a period of several hundred years which was warmer than our present day. It also appeared to remove the “little ice age” which occurred after the medieval warm period, which had strongly suggested that average temperatures fluctuate throughout history.  Doing so allowed Mann to misrepresent history and claim that the climate was mostly stable for about a thousand years up until the present, where he concluded that 1998 was the warmest year of the last millennium. “This claim was not, in reality, supported by data.”  “Furthermore, Mann put obstacles in place for subsequent researchers wanting to obtain his data and replicate his methodologies, most of which were only resolved by the interventions of US Congressional investigators and the editors of Nature magazine, both of whom demanded full release of his data and methodologies some six years after publication of his original Nature paper.  Most damning of all? “Mann had re-done his hockey stick graph at some point during its preparation with the dubious bristlecone records excluded and saw that the result lost the hockey stick shape altogether, collapsing into a heap of trendless noise. However, he never pointed this out to readers.”  Lastly, he also indicated that he had confirmed the statistical significance of his results, “yet when the scores were later revealed they showed no such thing; and by then he had taken to denying he had even calculated them.”  Essentially, he was caught lying in an attempt to foster a career advancing research paper. Though exposed as a fraud, the damage had already been done and numerous citizens, politicians, and activists have bought into it ever since. To this day, many individuals still believe in the supposed scientific consensus that began to emerge before this supposedly authoritative research was discredited.
NOT A CONSENSUS:
So why, to this day, do people still routinely hear the talking point “97% of scientists agree” when it comes to global warming? In 2013, Australian scientist John Cook - author of the book Climate Change Denial: Heads in the Sand - analyzed 12,000 abstracts (summaries of studies) and claimed “97% of climate papers stating a position on human-caused global warming agree global warming is happening and we are the cause.”  The problem? His method of review was so unthoughtful that it entirely distorted the results. Using the qualifier “papers taking a position,” Cook subjectively identified 34 percent of the papers as having supposedly expressed an opinion on anthropogenic climate change, and of that 34%, since 33% appeared to endorse anthropogenic climate change (in his assessment), he then divided 33 by 34 and got 97%. But as the National Review points out, “When David Legates, a University of Delaware professor who formerly headed the university’s Center for Climatic Research, recreated Cook’s study, he found that 'only 41 papers' of the 11,944 had endorsed what Cook claimed they endorsed.” That's only 0.3% of all 11,944 papers or “1% of the 4,014” that had specifically expressed an opinion. In addition, “several scientists whose papers were included in Cook’s initial sample also protested that they had been misinterpreted.”  Attempting to right this false public narrative, a 2015 NIPCC Report on Scientific Consensus advised the following:
“The claim of 'scientific consensus' on the causes and consequences of climate change is without merit. ...On the contrary, there is extensive evidence of scientific disagreement about many of the most important issues that must be resolved before the hypothesis of dangerous man-made global warming can be validated.”  (If interested in learning more about the many disagreements scientists have regarding climate change science, you're encouraged to read this cited paper.)
This isn't to say that Global Warming might not be true, it's simply to point out the extraordinary degree of ambiguity which exists within the research, complicated further by the numerous failed predictions by global warming alarmists. For instance, experts claimed the Arctic sea ice would melt entirely by September 2016. They were proven wrong.  While a 2013 IPCC report claimed that Antarctica was losing significant amounts of land ice, a 2015 NASA study used satellite data to debunk that notion and confirm that the Antarctic ice sheet actually gained in size nearly every year since 1992.  In a 1985 study, alarmists warned that “Beginning in a decade or two, scientists expect the warming of the atmosphere to melt the polar icecaps, raising the level of the seas, flooding coastal areas, eroding the shores and sending salt water far into fresh-water estuaries.” Again, we know this did not occur.  In 2007, U.N. scientists claimed the world only had eight years left to avoid the worst effects of global warming.  Eight years has passed and global devastation has yet to occur. Even Secretary of State John Kerry warned back in 2009 that "the Arctic will be ice-free in the summer of 2013. Not in 2050, but four years from now. Make no mistake: catastrophic climate change represents a threat to human security, global stability, and - yes - even to American national security." Again, this dire prediction never materialized, but no politician seems to answer for these fear tactics which empower them. 
And that's not all. For decades, the global warming alarmists were insisting that inclining CO2 levels were akin to pollution which would wreak havoc on our environment. Contrary to their projections, however, 28 years of satellite data have confirmed that the increased CO2 levels actually contributed to INCREASING global vegetation, since plants need CO2 to live.  And in addition to the above failed predictions, many continue to push the theory that natural disasters have been on the rise due to global warming. But per a 2014 International Federation of the Red Cross Natural Disaster Report, globally, there's actually been a decline in losses due to natural disasters. “Moreover, US hurricane and tornado activity trends since 1950 have remained flat or are decreasing respectively.”  Lastly, and most uncomfortable for those who insisted devastation was around the corner, satellite data confirms there's essentially been NO global warming since our last peak in 1997-1998. 
To conclude with full disclosure, we at WAC are not climatologists. We're admittedly speaking outside our field of economics and are understandably limited in that sense. We can't be entirely sure if global warming is a legitimate concern or not. What we CAN offer, however, is an economist's perspective; one which seeks to verify statistical significance, looks for flaws in predictive modeling, looks for replication of results, looks for sampling set errors which inadvertently or purposely skew results, one which examines historical literature and cross references old predictions with reality, and one which questions the legitimacy of public policy responses. What we can conclude is that there exists much ambiguity with this issue. Yes, most scientists agree that the Earth has generally warmed since 1800. Yes, many agree that at least some part of this warming was partially the result of human existence. Yes, many scientists agree that CO2 levels have likely increased. The disagreements, however, are largely over the depth of our presumed impact, if it's mostly natural or not, whether it's actually linked to CO2 levels, whether it's reasonable to allocate resources towards alleviation efforts, and whether successfully alleviating climate change is even within the realm of plausibility. It's absolutely sensible to debate these finer points and doing so doesn't mean one is ignoring evidence. A scientist, for instance, might be unconvinced that temperature levels are following CO2 levels while believing that climate largely fluctuates over time, yet they may still accept that we're presently in a moderate warming phase and that humans are indeed a minor contributor to that. They could believe this despite also believing that our impact is so negligible that it's unreasonable to adopt reactionary socioeconomic policies which damage economic growth in a vain effort to combat moderate climate changes. Unfortunately, in today's toxic political atmosphere, such a stance would have a scientist labeled “a science denier,” despite their views falling within the parameters of current research. As Mr. Pruitt correctly concluded, the intricacies of this debate are “far from settled,” and discussion “should be encouraged.” It's not as simple as “join us in saving the world” or “admit you hate science.”
http://science.sciencemag.org/content/123/3207/1061 (requires subscription)
http://harpers.org/archive/1958/09/the-coming-ice-age/ (an article about citation 4 with no subscription required, for those without a subscription to sciencemag.org)
https://www.nap.edu/catalog/12181/carbon-dioxide-and-climate-a-scientific-assessment (can be downloaded after logging in as a guest)
https://en.wikipedia.org/wiki/File:T_comp_61-90.pdf (photo of graph only)
found @ 769 likes ON 2016-12-13 15:22:56 BY ME.ME