Consensus in the climate science community means different things to different laymen.

  • For some, this is compelling stuff. “Scientific consensus? Time to assemble the team! Let’s take action!”
  • Others react differently. “Scientific consensus? That sounds suspicious.  Sounds like group think and motivated reasoning. Besides, wasn’t global warming proven wrong with climategate? I thought scientists were supposed to debate and disagree.  I don’t buy it, especially when mainstream media news clearly indicates theres an active debate on the issue. I smell a  rat.” (note – this may seem like I’m constructing a straw man. Perhaps. However, these are the rebuttals I’ve often heard when discussing global warming. I’ve simply assembled them into one statement.)

Me? I’m squarely in the first group. I won’t try to hide it.  However, I also know that people like me – people who have come to understand that modern global warming trends are real and caused by humans- are often accused of failing to listen to the people who still have doubts. We’re accused of being dismissive, or of being elitist liberals. (This one makes little sense to me as preserving our environment seems quintessentially conservative, but eh, not everything makes sense these days). (by the way –  name calling hurts in both directions).

Why I’m in camp #1: I’ve been reading about this subject ever since the mid-eighties, when my conservative Republican aunt mailed me a copy of an article from Time magazine. Recently, I’ve been overdosing on c-span testimonies to Congress, and analyses on the nasa website. Lastly, my training as an engineer has me valuing understandings as born out of the scientific method. But skepticism is an essential element to getting at the truth. So, let’s see if we can unpack that second bullet point.

  1. “Scientific consensus” is clear evidence of group think.  Group think is the tendency of a group to prefer harmony over debate.  Groups tend to jump to a conclusion in order to avoid argument. But if there’s any group that thrives on arguing, it’s scientists. Group think would imply that climate scientists have accepted a conclusion without fully investigating it.  Look  at the timeline though. Greenhouse gas theories go back to the 1890s. Rigorous study was going on from the 1950s through 80s.  Scientists deployed measuring equipment across the globe. They made models to project climate change to see if their theories were correct. The measurements rolled in and, lo and behold, the majority of their models under called the warming effects of greenhouse gas emissions.
    Recognition of group think, and other human biases, is what originally motivated the development of the scientific method over the past few hundred years. The scientific method is designed specifically to minimize the effects of these and other human biases. The scholarly peer review* process further minimizes mistakes and bias. For scientists to come together with a consensus statement is actually a big deal.  It’s an indication that the body of evidence is large and overwhelming. If this diverse group of people, trained in being rigorously skeptical, actually agree on a consensus theory, then hoo-boy, that’s something. The scientific method & peer review processes set the consensus bar very high. When it’s reached, we should take it very seriously.
  2. “Scientific consensus” is nothing more than “motivated reasoning” due to financial motivations or ideology.  Of course, consensus from a financially motivated group can be, and I would argue, usually is, biased. The tobacco industry demonstrated this. They outright paid scientists to argue that there was no link between smoking and cancer, even when leaders of that industry knew there was a link.  It absolutely happens. Today, there are a couple dozen organizations primarily funded by companies in the business of selling fossil fuels. Their consensus conclusions are that global warming is not human caused, or that even if it is, it’s not a big deal.  Studies generated by these think tanks have clear financial motivations.
    Climate scientists who agree with the IPCC scientific consensus on climate change, on the other hand, come from a diverse set of scientific societies,  academies, government agencies (including the US military) and intergovernmental bodies.  Their funding sources are diverse. It’s difficult to imagine that they are all colluding with one another when their funding comes from such a wide array of sources. When you look at the typical salary of a climate scientist, who employs them, and how much funding goes to the science community over time,  you see that there’s not a lot of money in this profession. Of course, you could look at organizations that bank on the consensus view – those which are in the pro-environmental business (Sierra Club, Greenpeace, Nature Conservancy, World Wildlife Fund, etc).  But these big money organizations are notably absent from the IPCC statement on global climate consensus. They make a lot of hay about the findings,  but they are not cited as original sources in forming the consensus view.
  3. “Scientific consensus” was proven to be bogus by Climategate.  In 2009, a server in the Climate Research Unit at the University of East Anglia was hacked. Emails were dissected by noted climate change skeptic James Delingpole. This journalist cherry picked seemingly-damning statements and made a big issue out of them.  He asserted that scientists were using ‘tricks’ to support conclusions they wanted to see. Ultimately, seven different independent investigations – one of which was sponsored by Senator Inhofe ( a self described climate skeptic ) –  found that there was no wrong-doing.  If you’ve got a free hour, I recommend  watching this BBC Horizons episode which discusses, among other things,  this scandal and aftermath.
  4. “Consensus” does not mean that climate scientists agree on everything. In fact, as in many science disciplines, they disagree on almost everything.  For them to be able to come together and actually agree on some fundamental theory, lends MORE credibility to the theory.

Here’s James McCarthy, Harvard University, Biological Oceanography Professor, testifying to Congress in 2010, on the  subject of scientific consensus:

<iframe frameborder=’0′ width=’512′ height=’330′ scrollable=’no’ src=’′></iframe>

So what is the ‘consensus statement’ anyway? In 2009, scientists from 18 different science organizations stated this:

“Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver.” (2009) –

Climate is a chaotic systems. There are so many factors, it’s nearly impossible to discuss the results of an experiment without losing a lay person in the weeds. Add to this the very common habit scientists have of attaching caveats and exceptions to every statement. By the end of a discussion, it’s hard to know what the conclusion is. They are truth seekers. Their whole objective is to find truth. They value truth so much they are unwilling to make simplistic statements without listing all the considerations, assumptions and exceptions. But we need clear statements. Finally, in 2009, they came together and agreed on a simplistic statement. This was a big deal for them. But somehow the simplicity of the consensus statement is somehow seen as making it untrustworthy. The absolute opposite is the reality. The fact that they were able to agree on something so fundamental means we should take it very very seriously.

*Peer review is the process of subjecting an author’s scholarly work, research, or ideas to the scrutiny of others who are experts in the same field, before a paper describing this work is published in a journal or as a book.   Be careful not to confuse confuse ‘peer review‘ with ‘publish or perish‘ – which IS a huge problem in some modern day science disciplines (especially food science) . It’s an issue in organizations where scientists are responsible for drumming up their own funding.)