Scientific agreement on human induced climate change: truth, myth or still open?

cartoon-climatologists colludingMany of us have heard the assertion that 97 percent of scientists agree that climate change or anthropogenic global warming (AGW) is being caused by emissions of greenhouse gasses that result from our modern lifestyle. Since some have questioned the validity of that statistic, this article seeks to understand where the 97 percent figure comes from.

Back in April 2013, an article was published in the journal Environmental Research Letters by John Cook, et. al. that claimed that “Among abstracts expressing a position on AGW, 97.1% [percent] endorsed the consensus position that humans are causing global warming.” This finding came from a meta-analysis of 11,944 climate abstracts from 1991–2011.

This certainly sounds impressive, and lends credence to the notion that nearly all scientists support the idea that we, as humans who emit greenhouse gasses, are responsible for climate change or global warming. However, we need to delve into Professor Cook’s analysis a little deeper.

Of the 11,944 abstracts he examined, 2/3 (66.4 percent) expressed no opinion on human induced climate change, while 32.6 percent endorsed the idea that climate change was being induced by mankind. The other 1 percent either rejected the idea of human induced climate change or were uncertain about the role of mankind in climate change.

So, only 4013 abstracts expressed an opinion on the role of humans in climate change and 3,894 of the abstracts indicated that humans were responsible, thus the 97 percent support. However, if the number of abstracts supporting the idea were divided by the total number of abstracts examined, the percent of scientific papers supporting the claim of AGW falls to 33 percent. This is further complicated by the fact that some of those 11,944 abstracts were by authors who published multiple abstracts on the subject. Therefore, only 33 percent of the abstracts support the theory that climate change is primarily the result of humans and whether that figure represents the percent of scientists is unknown.

Why does this matter?

Increasingly, we see the 97 percent of scientists agree figure in the media and more popular literature leading some to conclude that human induced climate change is a fact, not a theory! Since there are few things that over 90 percent of scientists agree upon, many people accept the theory as fact. However, if only 1/3 of scientists indicate that they are convinced that climate change is the result of our human activities, the subject becomes more hypothetical, still awaiting further evidence.

Read rest…

Trackback from your site.

Leave a comment (newest first):

Comments (7)

  • Avatar

    squidly

    |

    Unfortunately, Steve Lovejoy doesn’t seem to know much about the history of the 97% consensus crap at all. Firstly, the 97% consensus [b]did not originate with John Cook, et. al.[/b] Cook and Nuttercelli also claimed greater than 98%, but through detailed analysis it has been found that < 3% is the actual figure. The original 97% consensus was formulated through a poll that was mailed to a large group of scientists, whereby in the end, 75 of 77 (out of an original several thousand), giving to the 97%, agreed that humans were contributing to global warming. Steve Lovejoy, please, do a bit more research and fact checking before writing an article such as this. Accuracy and FACTS matter!

    Reply

  • Avatar

    Paul Homewood

    |

    Yes, about 1% actually said that more than half of warming since 1950 was caused by man.

    Most would agree that man has some effect on climate, if only uhi.

    The real question is how many agree that agw is dangerous.

    Reply

    • Avatar

      JayPee

      |

      Who cares who agrees ? The only thing that matters is proof. And there isn’t any.

      Reply

  • Avatar

    GR82DRV

    |

    If we could somehow take away the multi-billion grant funding machine for climate change research I wonder how many of those folks would still claim agreement.

    Follow the money.

    Reply

  • Avatar

    Steve H

    |

    Every major scientific society with climate science expertise has issued position statements on climate change that acknowledge its existence, the human contribution, and the concern for our future. This includes the largest one, the American Geophysical Union, with over 40,000 Earth and space scientists. Search the web for “AGU position climate change” to see it. Sure there are dissenting opinions, but they are most definitely a small minority.

    Reply

    • Avatar

      Gator

      |

      Statements by societies do not necessarily reflect the opinions of their memebership, and even if they did it only is an opinion. Science is based upon facts.

      I can show you a list of over 31,000 scientists who disagree with CAGW. How many names can you produce?

      Reply

    • Avatar

      amirlach

      |

      [quote] Sure there are dissenting opinions, but they are most definitely a small minority.[/quote] Actually, seeing as every single IPCC Model has been invalidated by observations, one has to wonder why “every major scientific society with climate science expertise” supports a “hypothesis” that has failed 100% of the time.

      The overwhelming majority of CAGW Models(100%) show that what your “experts” support is false.

      [img]https://informativestats.files.wordpress.com/2013/10/hayden_ipcc_arrow.jpg[/img]

      Reply

Leave a comment

Loading Disqus Comments ...

No Trackbacks.