Consensus Revisited: Do Scientists Still Believe in Anthropogenic (Human-Caused) Climate Change?

How has scientific agreement on the anthropogenic nature of climate change evolved in 10 years?

Scientific support for the link between human activity and climate change has strengthened to the extent that there is now near universal agreement. Whereas in 1996, reports hedged statements with phrases such as “the balance of evidence suggests…” (Houston et al 1996), this evolved to ‘it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century’ (Qin et al., 2014) and the more recent observation that  ‘human influence on the climate system is now an established fact’ (2021 IPCC Technical Summary). 

A new paper from an international team of researchers published today in Environmental Research Letters looks at how scientific consensus on anthropogenic global warming (AGW) has evolved over the last 10 years.  The research study led by Krista Myers and Peter Doran from Louisiana State University, with John Cook from Monash University and John Kotcher and Teresa A. Myers from George Mason University is based on the results of a survey of Earth Scientists conducted in September 2019. It follows the trail of a similar study carried out by Doran & Kendall Zimmermann in 2009. 

“Although there have been many studies finding a consensus amongst climate scientists, there’s little research into exactly how agreement has evolved over time and how different definitions of climate expertise shape that view,” explains John Cook. “This is the first time the methodology of the 2009 study has been replicated to measure how climate consensus has strengthened over time.”

Of the 10,929 Earth Scientists invited to take the survey, 2,780 responded. Across all definitions of climate expertise, the survey responses indicated that there is strong and robust consensus among geoscientists that the Earth’s temperature is getting warmer mostly because of human activity.

Out of all survey respondents who answered the primary question about the cause of global warming (n = 2,548), 91.1% responded that the Earth is getting warmer mostly because of human activity. This is roughly 11 percentage points higher than the 80% agreement found by the 2009 study when asking a similar question about AGW. In addition, the authors found that 100% of the most actively publishing climate experts – those who had published 20 or more climate papers each between 2015 and 2019 – accept that global warming is human-caused.

“The findings show that consensus has increased across the board. The findings also reaffirm that consensus increases with the level of expertise – the more you know about climate science, the more likely you are to understand that humans are responsible for climate change. Near 100% of scientists in our most expert group who identify as climatologists and actively publish in the peer-reviewed literature are in complete agreement that climate change is real and caused by humans,” says Peter Doran.

When analyzing the responses by subdiscipline, the authors found that those who self-identified as Economic Geologists had the lowest level of consensus with 84.1% agreeing with AGW.  The 2009 Doran and Kendal Zimmerman study also found Economic Geologists to be the most skeptical, but with a much lower 47% agreement with AGW which indicates a significant increase in consensus amongst this subgroup over the last 10 years. The authors also found a large increase in the level of agreement on AGW among those self-identifying as Meteorologists — from 64% in the 2009 study to 91% in the 2019 study.

The authors conclude that “given the persistent gap between expert consensus on anthropogenic global warming and public understanding, it is imperative to strengthen efforts to engage and educate people about the scientific consensus on climate change. Such efforts are essential to helping our society make more informed decisions about how to stabilize our climate.”

Reference: “Consensus revisited: quantifying scientific agreement on climate change and climate expertise among Earth scientists 10 years later” by Krista F Myers, Peter T Doran, John Cook, John E Kotcher and Teresa A Myers, 20 October 2021, Environmental Research Letters.
DOI: 10.1088/1748-9326/ac2774

Climate ChangeClimate ScienceGlobal Warming
Comments ( 9 )
Add Comment
  • Clyde Spencer

    “Scientific support for the link between human activity and climate change has strengthened to the extent that there is now near universal agreement.”

    This could be re-phrased to something along the lines of, “Why aren’t you on board when everyone else is?” That is, social pressure to agree with a common interpretation of facts.

    Science isn’t a hypothesis popularity contest! While there are commonly accepted paradigms that reign for years, they frequently get overturned as the heretics and apostates refuse to get on board, and dig deeper into the problem. As Einstein supposedly said in response to a group of 100 criticizing the theory of relativity, “Why 100 when it would only take one to prove me wrong?”

    Why does this consensus promotion not mention the infamous 97% claim?
    https://www.forbes.com/sites/uhenergy/2016/12/14/fact-checking-the-97-consensus-on-anthropogenic-climate-change/?sh=1c5167851157

    A less charitable criticism of the 97% claim, and by implication, similar claims, is as follows:
    https://iowaclimate.org/97-2/

    • Paul

      Clyde, that Forbes article is about half BS. The 97% figure was not based at all on Oreskes study. 97% was first arrived at by Doran and Zimmerman (the survey that this new study replicates 10 years later). Two other studies independently arrived at the 97% figure using different approaches (Cook et al. and Anderegg et al.). If you take the time to go to the actual published study https://iopscience.iop.org/article/10.1088/1748-9326/ac2774 you will see the 97% thoroughly. discussed and put in context of these NEW results

  • Eric Jones

    This whole thing of trying to get people to “believe” is preposterous. A scientist is always a skeptic. I don’t “believe” in anything. Just do the work…don’t ask me to sing on to a cause.

  • William Readling

    Yes, generally the planet’s climate is changing. It always has, always is, and always will be.
    Yes, human activity changes the climate. There are so many humans that need feeding, agriculture alone changes climate tremendously in some areas.
    How serious anthropogenic modification of earth’s average temperature is, compared to habitat destruction, poorly disposed wastes of all kinds, or city, highway, and lake/waterway creation, and modification, up for debate.
    The existence of temperature feedback mechanisms is probable. Sol’s radiated light has increased steadily as it’s metallicity increases. According to NASA’s SRO website
    “Since its birth 4.5 billion years ago, the Sun’s luminosity has very gently increased by about 30%”

    There has been liquid water on the surface of earth for at least 3.8 billion years. That’s the age of the oldest rocks found that show water’s effects, so a bottom limit really.

    Radiance of the sun probably increased 20% in the last 4 billion years, but there’s liquid water for almost all that time. Looks like a negative feedback mechanism to me. All human activities combined probably don’t change the planetary albedo a tenth of a percent, since some offset each other.

  • Tom

    What a bunch of horse sh@t. Climate change is a Khazarian Deep State piece of nonsense. In the 1970’s we were going to freeze in the 80’s we were going to boil and now we are actually heading into a global cooling period. Hang on to your hat folks this is starting to get
    interesting.

    • Neil B

      Tom, just go pound some more oxycontin and forget all about the bad people with the different opinions. It’ll all be ok.

      • Clyde Spencer

        That is not a constructive contribution. It is patronizing, as though you think that you are better than him. You certainly aren’t demonstrating that your self-opinion is warranted!

  • Yooper Logic

    This sounds like the same logic being used for the climate change agenda. ~20% responded and ~91% say it’s due to man. Chances are, the other 80% who did not respond feel differently, but in today’s cancel culture and with the government providing the greatest amount of funding, participants are doing a Sergeant Schultz.

    Did that big round ball in the sky respond? Wonder what her thoughts are?

  • Cynthia Binder

    Agw is evident. Looking forward n first-backwards. 🌍🌎🌏seriously outer space,earth,air,h²o,comets,then then compost of fossils fuel,c0².life now then or end,change .🍕pizza-home-time