Consensus.

I continue to follow the so-called Climategate stories with great interest.  This morning the most interesting comment thread appears to be at the NYT dotearth blog, with many comments from a variety of people including the apparently technically trained and from both "sides" of the AGW debate, if it can be said to have clean sides.

Let's talk a little bit about the "consensus," the one that supposedly includes
thousands and thousands of the well-informed.  Here is a little Venn diagram for you:

PEOPLE WHO HAVE AN OPINION ABOUT AGW (anthropogenic global warming)

Here we have some nested groups.  General public is on the outside.  Within that, laypeople with enough technical education -- they paid attention in high school or college science classes, they may have an amateur interest in science, etc. -- to understand the arguments about it that appear in newspapers, magazines, or the popular literature. 

Within that, technically trained scientists, engineers, statisticians, and the like.  I am a member of this group.   We know how research is supposed to work and maybe we know a bit about how it really works.  We might at some point have attended a seminar or taken a class on climate change, for instance, and at any case we know quite a bit of physics, mathematics, statistics and the like, and are used to reading and evaluating papers.  The key feature of this group:  We are all pretty sure that if we wanted to take the time to read the climate-change literature, take a look at the code, we could make an educated and independent judgment about it. 

A bit farther in, climatologists and oceanographers and geologists, perhaps a few biologists who specialize in species affected by climate change, earth scientists in general:  the sort of people who are expected to be familiar with the literature on AGW.  They know the research intimately.

And then in the middle, a much much smaller group: those climatologists, oceanographers, geologists who actually produce the research, write the papers, design the models, manage and manipulate the data.

I have no doubt whatsoever that, as you move inward from circle to circle, you see that a greater and greater fraction of the people are convinced that (a) the globe is warming, (b) it's caused by human activity, (c) there's something we could do about it.  That's what you call a "consensus."

What's not clear to me as a member of the third group from the center:  How much of that conviction rests heavily on the integrity and good judgment of the people farther in, and on the soundness and objectivity of the peer-review process?  This is especially important when you consider the interface between the two centermost circles -- because those second-ring people know enough and are familiar enough with the literature to critique the research of the inner-ring people, and then have the authority to add their voices to the "consensus" that is supposed to carry so much weight.

I rather suspect it's a lot.  I'll raise my hand right now and tell you that I am a trained scientist who has generally assumed the peer review process regarding AGW to work the way it's supposed to, and has assumed good faith and rigorous adherence to professional values on the part of the global-warming researchers (I don't assume they are unbiased -- who is?).  We're seeing a crack in that facade.  It's clear that the values are compromised at major research facilities.  That there's been an attempt to compromise the peer review process -- whether it has been compromised isn't clear, we haven't heard from the journals as far as I know.   My assumption wasn't valid.  Is my part in the "consensus" (such as my part was) back to square one?  Maybe so.