"My shoe is off, my foot is cold."
"Feel free to live on in your fantasy world. Out here in the Real One, the effects of climate change on our environment are now trivially easy to see,"
Thank you. Freedom is a beautiful thing. But I am not sure whom you are addressing, here.
The article did not claim climate change is not occurring. Neither did it say word one about probable cause. It did cite two sources that indicate that the warming trend has been exaggerated by around a factor of two. This is accounted for by miscalculation of UHI and a continually increasing trend of site violations (plus potentially bad FILNET and simply inexplicable SHAP).
As for urban effects, if you want to get technical, waste heat is a direct offset, but heat sink effect instead exaggerates a warming trend. And, of course, for a warming trend to be exaggerated, there has to BE a warming trend in the first place to exaggerate.
Note also that heat sink effect "undoes" itself in a cooling trend. So it is likewise possible that the sharp cooling trend of the last two years may be somewhat exaggerated as well.
"and their link to human endeavour is also all too clear. "
Taken at face value, surely. Human endeavor covers a very wide area indeed. it would include land use and "dirty snow", for two. What is not at all clear is how much CO2 affects temperatures.
CO2 is a greenhouse gas and has a positive forcing effect. Two vital factors are at issue:
First is the extent of the saturation effect (and how much "diminishing returns" are diminishing).
Second, and even more important, is that "positive feedback loop" theory (which multiplies the direct CO2 effects many times) has been called into extremely serious question by recent findings of the Aqua Satellite. AquaSat instead strongly indicates negative feedback leading to homeostasis. That would help explain the flat trend over the last decade.
"Oh by the way, we know all about climate cycles. The current change doesn't fit the pattern."
The multidecadal oceanic-atmospheric cycles (the "Big Six" being PDO, IPO, AMO, NAO, AO, and AAO) were unknown at the time Dr. Hansen made his 1988 speech; they were not even discovered until a decade or more later. The severe cooling over the past year and a ahlf has been attributed to a PDO reversal.
The Big Six all flipped, one by one, from cool phase to warm from 1976 through 2001. Temperatures warmed. Then they were "all on warm". Temperatures remained flat. Now PDO has turned cold, and NAO a,d AO may be wavering. Temperatures have cooled. Does anyone see a pattern here? Especially if the initial warming was overestimated in the first place? It certainly correlates better than the CO2 curve. And you can trace the pattern back to the last warming-then-cooling from the 1920's to the mid-70's.
Add in a "Little Ice Age Recovery" underpinning, and anthropogenic effects (land use, soot, and, yes, a bit for CO2 but no positive feedback loops) as a slight underlying trend, and it fits prety well. Certainly better than Dr. Hansen's climate models.
What can we expect? I'm sure I don't know. I'm equally sure you don't know, either.
And the Sun may be saving up spit for another Dalton or even Maunder-type minimum. We don't know about that yet. Normal cycles only vary tempertures by c. 0.1C, and claims that TSI is at a long-time high are in dispute, so I do NOT attribute 20th-Century warming to the sun.
But what if it's the very model of a Modern Maunder Minimum? (We don't yet know.) If that's the case, all bets are off--short-sell your carbon credits and invest in mink farms.
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We are left with many factors, each with a nice, healthy margin of error. There are ten times the number of students majoring in climatology these days, and a lot more attention being paid to the subject. The above and other questions will be answered, probably in another decade. But we don't know now. We simply don't. The only thing we know for sure is how badly the computer models have failed.
So before we dance the Kyoto with Stern and "invest" a third to a half of world growth on a continuing basis (greatest suffering to be borne by the worlds poorest, at a cost of many, many lives), I think we badly need to find out what is actually going on. This ignores the very real possibility that AGW is all too real but a "cheap, quick, dirty, and effective" fix can be found such as, but not limited to, reflective pole-to-pole satellites or a new power storage method. (Mix and match?)
And if we are going to find out what is going on, methods and procedures--on both sides of the debate--need to be conducted in the open. Don't you think?
In the meantime, make mine one of those non-fur, high-tech padded jobs. Poor Tom's a-cold!