Global Warming theory gutshot?

One of the things about the Anthropogenic Global Warming hypothesis (the idea that mankind is causing sudden, drastic, and irreversible warming by releasing Carbon Dioxide into the atmosphere) that has always struck me as the weakest part of the story is the "positive feedback" idea. It is suggested that as the globe warms, additional Carbon Dioxide will be generated (especially from microbial activity in thawed permafrost tundra). Thus, instead of the usual "negative feedback" typical to physical processes where trends tend to slow down and self correct, we would see a runaway acceleration.

Basically, this is like a rock rolling down a canyon wall that, when it reaches the bottom, accelerates up the far side. Oooohhh kaaaaaay. As I wrote on this:

The universe is stable because of negative feedback. The best (not to mention shortest) description of this is:

Name three positive feedback systems in nature. Get back to me on that when you're done.

Yeah, I know, there are some wicked smart scientists with all sorts of wicked smart models that say this will happen. So what happens when you - you know - actually do some experiments to test this?

From the University of California, Irvine press release, a finding that suggests soil microbes have a negative feedback with temperature increase. This has broad implications for the amount of CO2 emitted estimated in climate models. It had been assumed that as temperature increased, microbes and fungii would increase their CO2 output. Globally, this microbiotic contribution is large. The amount of CO2 released from soils worldwide each year is estimated to be about 8-10 times greater than the amount released by humans.

This study shows that soil microbes won’t go into a an “overdrive” mode when soil temperature increases.

Soil microbes produce less atmospheric CO2 than expected with climate warming

I don't know that this makes the whole AGW business gutshot; but I don't know that it doesn't. AGW has to have positive feedback, because CO2 is simply a very weak greenhouse gas. It won't cause almost any warming by itself, at least the quantities we're putting into the atmosphere.

No positive feedback, no run away warming. And this is the second set of observations that falsifies CO2-based positive feedback. The first was the historical record:

• From 1910-1940 temperatures rose, but CO2 did not.
• From 1940 to 1975 temperatures fell, but CO2 rose.
• From 1975 to 1998 temperatures rose and CO2 rose.
• From 1998 to 2008 temperatures fell and CO2 rose.
  

For three quarters of the last century, the hypothesis that increased CO2 will lead to higher temperatures is either not confirmed, or is falsified.

Weak. This is precisely what you would expect from a scientific "error cascade":

Strong evidence opposing it "can't be right" and weak evidence supporting it "must be right", and as a result, AGW is an astonishingly weak theory. In the last twenty years its proponents have made many predictions, most of which have been falsified. Michael Mann said that the Medieval Warm Period wasn't warm, contradicting recorded evidence from the period like the Domesday Book that showed wine vinyards in England in the eleventh century. AGW computer models predicted a warm layer in the middle Troposphere in the tropics; MIT's Jim Lindzen and others looked and looked - no warm zone. NOAA's Global Historical Climate Network (GHCN) is the most comprehensive store of historical climate data; people are finding that the data has been frequently, consistently, and mysteriously adjusted so that older temperatures are lowered below what the thermometer readings showed, and recent temperatures are raised above what the thermometer readings showed.

It's an error cascade of epic proportions.

That's certainly more plausible than a falsified positive feedback from CO2 still somehow leading to higher temperatures.

I'm not quite ready to say "stick a fork in it" - there's still a ton of momentum around AGW in the scientific community - but this is such a clear falsification of such a major theoretical justification, and it is so easy to repeat this experiment, that I simply don't believe that the scientific community will be willing to paper it over. Some will want to, of course, but this will be so blatant that in the end they'll only damage their own reputations.