Well Lucia has a post from Zeke which is experiencing a nice reception at her blog as well as Judith Curry’s. As often is the case, my own head feels about to explode over some of the “known details”. There are far too many otherwise smart people ready to accept them for my liking and the claims are far too poorly considered for even the pre-decided to accept.
Here are the thresholds of definition, although no quantitative analysis is given:
- Extremely likely > 95% probability
- Very likely > 90% probability
- Likely > 66% probability
- More likely than not > 50% probability
> 95% probability
Zeke provides this quote:
A doubling of carbon dioxide, holding everything else equal, would lead to a global average surface temperature increase of about 1 C. This follows from a basic derivation of forcing from changes to absorption bands, though it is complicated by the inherent difficulty of defining what exactly a no-feedback system is.
I would be fantastically happy to see just what BASIC derivation creates these numbers. Anyone have THAT derivation handy? And no–don’t start with the 3 point whatever forcing (someone asked that question on the last thread but I’m not blogging), because we are starting from absorption bands. Write it here folks…… Lots of unmoderated space below. Let the Id have it!! I have looked for this since starting this blog and if you tens of thousands of readers have hid it from me with intent? That would mean war!
> 90% probability
Stocks of atmospheric carbon have a relatively long lifetime. While any individual molecule of atmospheric carbon remains in the atmosphere for only a few years on average, the growth limitations of sinks means that the stock will not decline quickly should emissions stop increasing. As a corollary, arguments that 95 percent of annual CO2 emissions are natural rather miss the point.
Again, I’ve read multiple poorly conceived litrachures on this subject. Anyone with a basic proof for the lifespan and true sink capacity of earth? My god this stuff makes me nuts. Does anyone, anywhere on this third rock from the sun (we are the third right?) claim to really know this answer? Michael Mann for instance? Zettatons .. whatever.. of rock with water flowing through it has a funny ability to absorb/react with mere parts per million of whatever trace molecule might be present in the ground/rain water passing by. Even Mann’s calculator doesn’t have that many significant figures. Continued below:
Stocks of atmospheric carbon have a relatively long lifetime. While any individual molecule of atmospheric carbon remains in the atmosphere for only a few years on average, the growth limitations of sinks means that the stock will not decline quickly should emissions stop increasing.
You would think that this would be a settled issue, the atmospheric lifespan of the CO2 molecule and the size and ability of the Earth to absorb them– it is not, except for in a few peoples minds. I wonder if any readers have considered how unlikely it would be for a planet to maintain a very highly emitted molecule (every mammal on the rock, every fire, nearly every oxygen combustion event) at a hundreds of parts per million level for millions of years without large high capacity sinks having the ability to deal with increased output. How unlikely would that be? The IPCC would have us believe that we are on some precarious balance whereby the sink doesn’t accelerate or perhaps our extreme lack of CO2 occurred by accidental balance. The likelihood of such a situation seems a bit extreme to say the least.
As a corollary to 3., a warmer world will have an atmosphere with more water vapor. This will tend to enhance the greenhouse effect, though the situation is complicated by the difficulty in both projecting changes in cloud formation and determining the radiative forcing effect of clouds.
OK, so this is the feedback issue. There isn’t a shred of ‘solid’ data which properly interpreted supports the claim that moisture increases or decreases the effect. Not one damned ‘properly interpreted’ shred of evidence, yet people chuck it out there as though it were real. The only papers which I have found mix cause and effect through pre-determined methods. White reflective clouds vs water vapor, the proof being models which have parametrized nature out of the issue. There isn’t any knowledge whatsoever by mankind on this point in my properly humble opinion. Of all things climate, this issue is one which we really DON’T KNOW! We don’t know a worthwhile thing about moisture feedback direction or magnitude and that is something I firmly know.
Prove me wrong, give it a whack.
Direct solar forcing has played a relatively minor role in the last four decades, as TSI has been flat-to-modestly-decreasing during that period.
Again Zeke gives a vastly overstated confidence in this issue from my perspective. What we know about stellar emission effects is probably equivalent to the average high school student’s grasp of calculus. I won’t bash this as much though because several measures have been reasonably stable but the measurements are so extremely limited that the claim is ludicrously confident. Hell we couldn’t even predict sunspots within 3 years in the last cycle. There are solar emissions recently (four decades) measured which can have effects on climate though which have been excluded as causes of measured warming but the statement is WAY over the top IMO. We only learned to measure air temps by satellite in 1978 and anyone who thinks those records are clean is either ignorant or insane, they are simply more quantifiably contaminated than the surface stations. There is no complete solar record for the 40 year period by which any scientist can make the above claim. TSI – total solar irradiance. It may be possible that the sun has not changed much – I don’t know – but there are poorly quantified solar emissions UV, X ray, Particulate etc. which may have equal or greater short term effect than our measures of what was previously termed TSI.
What I think is likely [>66% probability]
Climate sensitivity is somewhere between 1.5 C and 4.5 C for a doubling of carbon dioxide, due to feedbacks (primarily water vapor) in the climate system. This is supported by multiple lines of evidence, including GCMs, paleoclimate evidence (including climate response to forcing during glacial periods as well as millennial proxies), the instrumental record, and the climate response to volcanic forcings among others
I’ll just reword this one for proper clarification:
This is UNsupported by multiple lines of evidence, including GCMs with pre-concluded output, numerous mathematically unsupportable paleoclimate papers (including unrealistic interpretations of proxy response to forcing during glacial periods as well as variance suppressing algorithms applied to suspected millennial proxies), the problematic instrumental record etc.
Zeke and I could spend about ten rounds on that one alone.
Land and ocean temperature measurements over the past century are largely accurate at a global level, though there are some regions that have limited data, especially toward the earlier part of the century. That said, factors like UHI, instrument change, siting issue, and other data quality issues could potentially change the global trend modestly.
I flatly deny that there is any evidence that land measurements have accuracy of tenths of a degree. The claim ‘largely’ accurate is qualitiative, yet the claims of ‘the warmest year ever’ (which Zeke doesn’t make here) are unsupportable by anyone with any science in their bones. While it may be true, anyone with a hint of suspicion knows the ocean records have been tweaked and beaten into the proper shape. We with functional brains know land station sighting is a real factor. And this is coming from a guy (me) who KNOWS 100%, not 99, 95, or 80% , CO2 CAUSES WARMING!
Intrinsic (unforced) variability plays a relatively large role globally at an intra-decadal scale, but is relatively insignificant at multidecadal scales. In this view, the early 20th century warming was due primarily due to solar forcings and a volcanic lull.
Yeah……Okay.. Well we’ve covered the rest, how do we know this?? Just where is the proof that oceans cannot affect multidecadal temps? Any concept that the oceans have an average temp of like 3C with a high average surface temperature? Any idea that perhaps mixing of water could cause problems for this pseudo-spherical rock? There is a huge amount of energy capacity there. With ocean currents, even multi-centennial and multi-millennial scales are questionable. Sorry but this flatly doesn’t fly with me.
Recent warming is unprecedented over the past millennium. While there are plenty of problems with paleoclimate reconstructions, enough corroborating work has been done to at least elevate this to more likely than not in my personal judgment. Were there reconstructions clearly showing MWP temperatures comparable with, say, the running 50-year mean of the instrumental record I would be less certain.
Start with the bold – Bull! Then work on, ‘corroborating’ evidence in paleo is not as self confirming as it might appear. If we all use variance suppressing math and data, we all will get the same variance suppressed answers. Regression is regression is regression. I’ve written endlessly on the subject and these claims have the same degree of content as a US projected budget. A firm example of writing without enough reading IMO. I like Zeke because he is honest, I like Bart for the same reason but I don’t like bad science even when it is honestly presented and in my opinion the above claims despite the uncertainty escape clauses were/are bad science.
We don’t know the past climate.
We don’t know the future climate.
Claims to the contrary are, have, and will continue to be — as common as blades of grass.
And in case you were somehow confused, I am not blogging!! I’m really not, there is no time for this nonsense.