In an argument, between those who believe climate change is natural, and those who support man-made global warming, someone is going to throw the “97% consensus among scientists on global warming” card or something similar. By “consensus”, the idea is that scientists consider this a “no-brainer”. The planet is warming up, we’re contributing to it, and 97% of the scientists agree.<\/p>\n
The reality? That consensus doesn’t exist. This is based on a study done on a selected number of peer reviewed studies. A look at the actual study does not support the 97% consensus claim. There’s not enough information in the paper to conclude, or infer, that there is a consensus in the scientific community regarding global warming.<\/p>\n
From the study’s abstract:<\/p>\n
We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming.<\/p><\/blockquote>\n
The study was done in phases. The first phase started with a keyword search of their database.<\/p>\n
The two keywords used were “global warming” and “global climate change”. Most of the people, who have done searches on the Internet, via keyword, would know that different combinations of keywords tend to provide different compositions of results. Why not use something like “average temperature change”, “climate cycles”, “space weather”, “climatic optimums”, “climatic minimums”, or other keywords that could also bring up climate related articles?<\/p>\n
By using “global warming” or “global climate change”, the researchers are attempting to get results that would point to a majority agreeing on man-made global warming. Out of the thousands of academic journal articles available, a researcher could drastically narrow down the results. The kind of results they get depends on the keywords used to search those articles.<\/p>\n
The timeline used for this search went from 1991 to 2011 excluding papers generated before 1991. Considering that it has been more than five years since the “newest” paper considered for the study, this time range is automatically out of date. Additional studies have been done since 2011, with an increasing amount of the studies pointing to the sun and other natural causes for climate change. The “universe” of results and studies have changed our understanding of the topic since then.<\/p>\n
Yet, people would like to throw the “But there’s a 97% consensus that the planet is warming and people are behind it” argument.<\/p>\n
Out of the results, the researchers pulled the abstracts out, and categorized them. These abstracts were sent to those who rated these abstracts on whether are not they supported man-made global warming. The results are shown in the abstract, with most of the papers reviewed, out of the 11,944 papers considered, not taking a position on global warming. That was a whopping 66.4%, with the balance going towards those that specified agreement or disagreement with man-made global warming. From this balance, 97.1% supported manmade global warming.<\/p>\n
From there, the researchers sent 8,547 invitations to the authors of the papers. They received 1,200 responses from these authors. After they narrowed that list down to 1,189, they invited these authors to self-rate their paper’s support for global warming.<\/p>\n
From the 1,189 scientists, reviewing 2,142 of their own papers, 97.2% endorsed man-made global warming.<\/b><\/p>\n
This is where the 97% shows up. This is the “97% consensus” that is used to argue that the majority of scientists “agree” to man-made global warming. If you’ve read this far, you could tell, by the numbers, that 97.2% of 1,189 scientists does not constitute a near consensus of all the scientists.<\/p>\n
Now, ready for the kicker? From the paper itself:<\/p>\n
Nevertheless, 11,944 papers is only a fraction of the climate literature…<\/p><\/blockquote>\n
A fraction of those 11,944 papers doesn’t constitute a scientific consensus, within the scientific community, on manmade global warming. The so called “scientific consensus” supporting man-made good warming doesn’t exist.<\/p>\n
You could download the study itself from here: <\/p>\n