I am a fan of both Anthony Watts' site Watts Up With That *AND* John Cook's Skeptical Science... both are run by real people who go the extra distance find the best links to their sources (not some blog chain) and both are considerate of the reader.
Here's a small research journey: Direct CO2 rise causes temperature rise (CO2drivesT)? YES or NO?
There has been a demonstrated correlation between CO2 and temperature shown by Antarctic ice core data (within ~800-1000y). If a rise of CO2 in this data should consistently lag behind rises in temperature then CO2drivesT is not ruled out (both may be responding to some other factor but at different rates) BUT CO2drivesT has fallen down a notch... it now requires more extraordinary proof.
Even though human-driven global CO2 has risen 'terrifyingly fast' to 400ppm -- empirically speaking I am not terrified -- because the temperature rise that should accompany such a SHOCK by any reasonable interpretation of CO2drivesT, and to any reasonable extent, has not arisen. The effects of this 'causation' are missing.
Which is to say the historical correlation is broken.
That is not necessarily a bad thing. It's a thing,
Something we should be concerned about.
The rise to 400ppm is definitely humans' fault. It is 'massive'.
Temperature has not risen.
So such a causation, if any may exist, is unlikely to be significant.
We'd see it by now.
For example, head for Skeptical Science [SS] [SS] CO2 lags temperature - what does it mean which acknowledges that CO2 lags behind temperature but introduces 'CO2 amplification' which asserts a feedback where "the increased CO2 in the atmosphere amplifies the original warming.". This in itself is another extraordinary claim. While such a feedback might certainly exist I cannot just swallow it as a flat-fact when pursuing a simple answer to the CO2drivesT question. Where are the computer models incorporating this feedback that match observed temperature?
There is a stir these days among CO2drivesT proponents that some mechanism must exist that is hiding or delaying the warming that the models predict. Immature 'skeptics' jeer at this, implying that it is all about protecting the sacred forced-feedback hypothesis at any cost. Immature CO2drivesT proponents accuse them of attempting to derail the scientific method. There is a germ of truth in both. I think everyone should grow up a little.
Aside from the modern lack of warming, one thing seemed odd about amplification. In the Vostok ice core CO2+T graph clearly at ~75,000YA there is a massive injection of CO2 (~225-230ppm) that I think is Toba era volcanism. If such amplification exists and is significant, that would have been a fine time for CO2 feedback to jump in and 'save the day' with a slowing or a plateau of the declining temperature trend. Or even a rise? But 6,000 years after its onset -- on the Vostok graph at ~220ppm temperature and CO2 are once again in lock-step, both in steep decline. After some six millennia of 'higher' CO2 and 'lower' temperature. Plenty of time for particulates to settle and 'amplification' to occur. If it does. Did it?
But never mind, it's all changed, that [SS] Lag, what does it mean? page also said something astounding: "In fact, about 90% of the global warming followed the CO2 increase." 90%... is that a fact.
Since when?
Which led me to the next step where the game-changer is supposed to be [SS] Shakun et al. Clarify the CO2-Temperature Lag which asserts for the last interglacial period (at least), and in the Northern hemisphere (at least), temperature has lagged CO2.
Which is another extraordinary claim. Apparently it is the extraordinary result of Jeremy Shakun et. al., which was obtained by aggregating a cocktail of ~80 sources of temperature proxy data, which led Willis Eschenbach down a rabbit hole into state of apoplexy (apoproxy?) as he attempts to dis-entangle the proxies, lay out some criteria for validating this approach and (fairly) pointing out problems with ice core CO2 measurement, then fails to use their data to prove that warming began South and progressed Northwards as claimed, finds only 8 out of 80 of the proxies which show a clear trend and fails to find the proof, even pointing out that their Antarctic curve might be off by 2,000 years. While I'm no expert, in Eschenbach's analysis I discern a great deal of due diligence, little nit-picking and mostly a sense of astonishment that such an amalgamation of proxy-data could refute globally the trend that is so clear in the stable Vostok signals.
As a layman would I personally be ready embrace the idea that these disparate ~80 proxies taken together in the way that Shakun presented them, can give a truly accurate and comparable temperature record? Not lightly. The errors and side-channel noise of some of the proxies relegates them to the realm of the interesting but not the accurate and incontrovertible. If Eschenbach's analysis proves anything it may be that this CO2-lags-temperature issue is surely not settled. Does it take a so-called 'skeptic' to delve deeper?
So I am left with the CO2 following not leading temperature in paleoclimate, not proven otherwise to my satisfaction. I am left with a purported 'amplification' effect with no direct observation of it happening despite CO2 rising to 400ppm.
The clear and extraordinary proof required to show that there is a direct causation and steeply rising CO2 is causing warming to a degree beyond historical norms... as yet, still waiting.
The folks at Slashdot who jeer and mod 'troll', turn the water white with foam and gnashing of teeth when they smell skepticism about this topic -- well, that is another phenomenon...
Oh yeah, that sea level rise stuff, it's a real hoot. It's hard for a realist to be terrified of centimeters of rise over centuries when twenty-foot waves might arrive tomorrow: welcome to Earth. Only shocking and exciting to people who have already built on (flood, storm surge, below sea level) plains, never factored in natural subsidence and are looking to have their flood insurance premiums subsidized by evil energy companies. Ice changes/shelf calvings at the poles: welcome to Earth. Even the most compelling arguments sound (to me) like all the creatures of Bambi's forest scurrying in terror after someone farts.
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Bumps to Thorium Remix and my own letters on energy,
To The Honorable James M. Inhofe, United States Senate
To whom it may concern, Halliburton Corporate