The Claim: This chart settles the debate on whether scientists accept or reject global warming by showing that a clear plurality of peer reviewed studies accept that global warming is caused by humans.
The Verdict: False. This pie chart proves that two articles reject human- caused global warming. AND NOTHING ELSE. There is no given evidence about the number of articles that blame humans for global warming. The number could be between 0 and 10,883, but no evidence is provided by the study.
It’s not that this chart isn’t technically correct. It’s just that the information it construes is fundamentally flawed. However, that won’t stop members of the media and people who like sharing things on social media because it reinforces their previous held beliefs. The crux of the problem is that the original study is, at best, misleading and author James Powell’s methodology is too simplistic.
The study is centered around a single question, do you reject anthropogenic global warming? To find the answer to his question, Powell searched through Web of Science peer-reviewed articles about global warming and then examined whether or not the authors explicitly rejected any kind of relationship between human activity and global warming.
This is where the issue lies. By placing the burden on authors to explicitly reject human contribution to climate change, he loads the question and completely loses any modicum of neutrality.
Powell’s study includes all papers, even ones that don’t explicitly endorse anthropogenic climate change, in the yes column. Taking a sample of his cited works from the 2012-2013 study we find that he has included:
Effect of Climate-Related Change in Vegetation on Leaf Litter Consumption and Energy Storage by Gammarus pulex from Continental or Mediterranean Populations Effect of delayed sowing on yield and proline content of different wheat cultivars Effect of Different Light Emitting Diode (LED) Lights on the Growth Characteristics and the Phytochemical Production of Strawberry Fruits during Cultivation Effect of different tillage and seeding methods on energy use efficiency and productivity of wheat in the Indo-Gangetic Plains Effect of elevated CO2 on degradation of azoxystrobin and soil microbial activity in rice soil Effect of fish species on methane and nitrous oxide emission in relation to soil C, N pools and enzymatic activities in minted shallow lowland rice-fish farming system Effect of Global Warming on Intensity and Frequency Curves of Precipitation, Case Study of Northwestern Iran Effect of High Reactivity Coke for Mixed Charge in Ore Layer on Reaction Behavior of Each Particle in Blast Furnace Effect of long-term application of organic amendment on C storage in relation to global warming potential and biological activities in tropical flooded soil planted to rice Effect of long-term operation on the performance of polypropylene and polyvinylidene fluoride membrane contactors for CO2 absorption Effect of maize intercropped with alfalfa and sweet clover on soil carbon dioxide emissions during the growing season in North China Plain Effect of morpho-physiological traits on grain yield of sorghum grown under stress at different growth stages, and stability analysis Effect of near-future seawater temperature rises on sea urchin sperm longevity Effect of nodule formation in roots of hairy vetch (Vicia villosa) on methane and nitrous oxide emissions during succeeding rice cultivation Effect of origin and composition of diet on ecological impact of the organic egg production chain Effect of permafrost on the formation of soil organic carbon pools and their physical-chemical properties in the Eastern Swiss Alps Effect of predicted sea level rise on tourism facilities along Ghana’s Accra coast Effect of rainfall exclusion on ant assemblages in montane rainforests of Ecuador
All as positive matches proving anthropogenic climate change because they don’t explicitly reject global warming. Even if only one percent of the papers in the Powell study actually endorse the idea of global warming, they are still included in the total. Based on Powell’s own data and chart, the only thing he proves is that two papers meet the standard set in his methodology, which is whether or not “a paper rejects human-caused global warming or professes to have a better explanation of observations.”
Therefore, because Powell never actually examines the data other than to validate his original question. The number of articles that accept humans are a factor in global warming could be between 0-10,883. It’s not 10,883 studies confirming global warming. It’s two that are rejecting it. This sneaky and dishonest methodology only provides fodder to climate change deniers by overselling the problem and not providing an honest look at the actual numbers.
Furthermore, Powell’s study makes no distinction between future estimates of the effect of global warming. No matter how small or insignificant the warming may be it is counted in the “yes, humans cause climate change” number. If the papers found human activity resulted in a 6.0 Fahrenheit increase in temperature, it’s treated the same as a paper that finds humans have only caused 0.1 Fahrenheit of warming.
In other words, from this study there’s no way to tell who thinks climate change is a serious problem, could be a problem, or won’t be a problem. And that really is a problem.
While the study itself has issues, an equal concern is the misinformation that gets attached to the preceding pie chart by members of the media.
Salon’s Lindsay Abrams is already touting the chart with the headline “10,853 out of 10,855 scientists agree: Global warming is happening, and humans are to blame.” Well first off Lindsay, neither the article or the original study ever mentions the number of scientists. It’s 10,855 studies, and whether or not they were done by 10,855 different scientists is pure speculation. It’s possible that 1,000, 20,000, or 150,000 different scientists were cited in the study.
[UPDATE] Salon finally got the memo and they changed the headline to “10,883 out of 10,885 scientific articles agree: Global warming is happening, and humans are to blame.” However, you can still see the original title in the URL slug.
Lindsay also posts:
UPDATE 3/26/2014 9:27 PM: The headline of this post has been corrected to reflect the correct number of articles referenced by Dr. Powell’s research. Powell also clarifies that many of those studies were authored by multiple scientists, so the complete number is actually higher. The headlines has been updated to reflect this as well.
On his methodology, Powell notes, he only verified that two out of the 10,885 articles he found concluded that anthropogenic global warming (AGW) is wrong: “It is a safe assumption that virtually all the other 10883 do not reject–that is, they accept–AGW but I can’t say for sure that each one of them does.”
It’s nice of Powell to admit he didn’t actually read each article, and also make the assumption that if you do not reject global warming that that means you automatically endorse the idea. No room for “we don’t know” in the world of climate science.
Business Insider trumpets “The Scientific Debate in One Chart” and basically declares all scientific inquiry into global warming to be over, all the while ignoring the obvious discrepancies and dubious methodology of the study.
Weather.com, goes even further:
“[B]y reject, I mean they either flatly said global warming was wrong – which people say all the time in the press and in front of Congress – or they said there’s some other process that better explains the information,” Powell said in an interview with weather.com.
Single data points that disputed man-made climate change within a paper on another topic didn’t meet his test, he added. If a paper proposed an alternate theory for global warming, it had to have the goods.
He emphasizes that he was looking for the number of scientists who reject anthropogenic global warming – not how many accept it.
“You don’t have to poll scientists or talk to people. All you have to do is read the papers and see what evidence is there,” he said. “I think … people’s opinion is less important than the scientific evidence that backs up opinion.”
Never one to not have a stupid opinion about something he doesn’t understand, BuzzFeed’s Andrew Kaczyinski gets into the act by declaring “Nearly Every Scientist Says Global Warming is Caused by Humans.”
— Andrew Kaczynski (@BuzzFeedAndrew) March 26, 2014
Dynamite job on not reading the study Andrew, but shouldn’t you have responded in the form of a listicle?
If the mainstream media buzz is any indication, you’re likely to see this chart bouncing around Facebook, Twitter, and Google+ in the next few weeks (well not Google+, because who actually uses that?). But when you do, instead of blindly accepting this misleading information, take a second to actually think about it. You don’t even have to take my word for it, get in there and read the original study. Read the wildly exaggerated claims that will be made by the media. Does the information really match up?
It merely states that out of 10,885 peer reviewed articles that included the words global warming and climate change, two explicitly rejected anthropogenic global warming.
It’s a bad chart that is meant to mislead and squash actual debate.
And that’s why I had to MEMEBUST IT.