Now even Australia's ABC is asking questions about the new IPCC report and why Dr. Richard Tol asked his name to be removed from it

I am still awaiting rationale as to why a trace chemical 4/100 of 1 % can cause anything,
Why? Isn’t the physics of this clear enough? The atmosphere is optically opaque in the CO_2 linked frequency bands with a very short mean free path of photons in these bands. It efficiently absorbs LWIR in these bands, and the CO_2 molecules that absorb the energy almost without exception collide with other air molecules and transfer that energy to them before/instead of reradiating it.
If the CO_2 were not there, dry air would be nearly completely transparent to LWIR and surface radiation would travel directly to outer space without warming the atmosphere. The colder atmosphere would radiate much, much less LWIR back at the surface — less because it is colder, less because it has no energy levels likely to be excited at the molecular energies corresponding to their temperature. The surface would receive, on average, less total energy in the form of radiation and the air in contact with it would be, on average, colder and more difficult to warm. The surface would then be colder.
As it is, the CO_2 absorbs a substantial amount of the radiation the surface emits, warms the air, and reradiates it back in the direction of the surface. The surface warms until its outgoing radiation rate compensates for the additional back radiation self-consistently. It is really pretty simple.
The cooling process of the dry atmosphere is also slowed by the presence of CO_2. The outgoing radiation that is absorbed near the surface that warms the atmosphere as noted warms the whole atmosphere, not just the CO_2 molecules. The dry atmosphere (warmed at the bottom, cooled at the top) is convectively unstable and as it circulates up and down in convective rolls it establishes a thermal profile called the dry adiabatic lapse, where it gets cooler as one gets higher and the atmosphere less dense without actually losing energy (because O_2 and N_2 radiate only very weakly at the temperatures involved). CO_2 is internally radiating all of the way up, but until you reach a sufficiently low density (so that the mean free path of LWIR photons in its radiation coupled bands is large enough that photons have a substantial probability of escaping from the atmosphere altogether with no further absorption) the photons are simply reabsorbed elsewhere, up or down or sideways, in the atmosphere with only a slow diffusive transfer of energy. The temperature of the atmosphere at the height where they finally become a channel through which the atmosphere itself can cool is much lower than that of the surface, and as a consequence the radiative flux from the much less dense CO_2 at that height is much smaller than the flux that would have been lost directly from the surface in precisely those bands if the dry atmosphere had no CO_2 in it.
With CO_2 or without it, the Earth SYSTEM has to emit radiation at the same average rate it absorbs it. The total incoming radiation rate is approximately independent of the presence or absence of CO_2 (which is not a good reflector, it is a good absorber). The rate that it emits it is either the rate it is emitted straight to space from the surface (no CO_2, atmosphere a weak absorber and radiator), determined by the temperature of the surface, or it is the sum of the rates it is emitted by the atmosphere to space in the greenhouse bands and emitted by the surface to space in the unblocked bands. The rate that it is emitted by the atmosphere to space in the greenhouse bands is strictly lower than the rate the warmer surface would emit in those same bands straight to space without CO_2. Consequently the surface must emit at a higher rate in the unblocked bands to balance the unchanged incoming rate of radiation. The only way it can radiate at a higher rate at all is by being at a higher temperature. End of story.
Note that this latter argument doesn’t depend in any meaningful way on whether or not the atmosphere is absorbing incoming energy as well as outgoing energy, or where that absorption primarily occurs. It only depends on the average temperature at which it radiates, and the fact that that temperature, for a variety of reasons, is almost always substantially cooler than the surface temperature.
In a non-dry atmosphere things are indeed more complicated, because water vapor is a more powerful and more prevalent greenhouse gas in ITS absorption bands, and because water vapor can undergo phase changes and contribute huge nonlinear shifts in albedo (that can reflect both incoming radiation before it warms the surface, and surface radiation that would otherwise escape to space outside of the greenhouse bands). But the idea is still the same — as long as any part of the total outgoing radiation is being emitted from gases at a much lower temperature than the surface in bands where the direct loss from the surface is blocked, the Earth system itself will not be in balance until it warms in unblocked channels enough to compensate.
There is direct, unambiguous evidence in the form of top-of-atmosphere downward direct spectrographs that clearly, unambiguously, show the radiation holes in the greenhouse bands, and equally clearly connect the mean temperature/rate of radiation in those holes to the expected upper troposphere temperature where the atmosphere becomes transparent in those bands. These spectrographs are essentially a photograph of the GHE in action. No physicist — no non-physicist — who sees these spectrographs and understands the simple ideas of detailed balance, radiation theory, and thermal radiation can possibly doubt the existence of a “greenhouse effect” even though the mechanism is ill-named and has little to do with the mechanism that warms actual greenhouses (which is as much blocking of convective losses as it is blocking of radiative losses and where the DALR is irrelevant).
It does the skeptical argument no good at all for skeptics to reveal a vast general ignorance of detailed balance, radiation theory, and thermal radiation in the first words out of their mouth in any given discussion of the greenhouse effect and global warming. The issue is not whether or not there is a greenhouse effect or that the effect itself makes no sense or isn’t substantially causally linked to a “trace gas” (that is present in sufficient concentration to make the atmosphere opaque to in-band LWIR hundreds of times over) — it is what marginal or differential variation in surface temperature one expects long after one passes the nonlinear threshold where the atmosphere first becomes opaque. If a mirror is already (say) 95% reflective with a silver coating 0.01 mm thick, it doesn’t become twice as reflective if you make the coating 0.02 mm thick. Maybe it makes it 96%. Maybe it makes it 98%. Maybe it makes it 99.9%. But at that point the marginal gain possible from thickening the silver is very, very limited.
The atmosphere is of course a lot more complicated. It is simultaneously already deeply saturated in CO_2 (so that doubling CO_2 can have only a very small effect at best) and it has multiple nonlinear coupled mechanisms that can either augment or cancel whatever effect a change in CO_2 might (all things being equal) otherwise have produced. The total feedback in those other mechanisms, in other words, can be positive or negative.
In the case of the actual atmosphere, the original GCMs from Hansen’s day on have asserted and implemented feedback (especially from water vapor) so strong that it actually exceeded the direct warming expected from CO_2. This is precisely the opposite of what one intuitively expects for an otherwise stable system — otherwise one has to explain why water vapor doesn’t all by itself cause a positive feedback ongoing warming — the Earth (say) warms a degree due to some natural fluctuation, which causes it to warm a second degree from positive feedback on that fluctuation, which causes it to warm a third degree from positive feedback on the positive feedback, to the point where even if the original fluctuation disappears, you now have runaway feedback from water vapor alone.
A small but (I think) increasing number of people (including many climate scientists) either already have long believed or are starting to believe based on substantial evidence that Hansen’s assertions of strong positive feedback are wrong, that net feedback is likely neutral to negative or at most only very weakly positive. This slow change in the position of climate science itself is “reflected” in the systematically decreasing estimate of total climate sensitivity, the supposed sum of direct CO_2 linked warming and all feedbacks. It has gone from Hansen’s originally egregious claims of 3 to as much as 5 or 6 C by 2100 down to where there is a bit of a battle to hold climate sensitivity on the high side of 2 C. Direct CO_2 linked warming is believed to be ballpark 1 to 1.5 C (where the physics itself isn’t well enough known to specify it more accurately, and where it is impossible to directly measure it or infer it from existing measurements of the multivariate climate system with its substantial natural variation). The total feedback has thus dropped from a multiplicative factor of as much as four — three parts of the warming due to water vapor feedback to one part direct warming by CO_2 — to less than 2, no more than one part water vapor to one part CO_2.
The actual range of hypothesized values has substantially increased, with some people asserting negative feedback from water vapor for a total climate sensitivity of as little as 0.5 C (one part to CO_2 accompanied by minus a half part from water, largely due to increases in albedo that outweigh any increased greenhouse effect from water vapor per se), some people asserting nearly neutral (no net) water vapor feedback so that the direct warming from CO_2 is all we are likely to see, somewhere around 1-1.5 C total by 2100 plus or minus natural variations not unlikely to be on the same general scale, and with some people still asserting a half-part or so positive feedback for a total around 2.2-2.4 C by 2100. Only hard core warmists still are holding on to more than this, and they are as much an embarrassment to the warmist side of the debate as greenhouse effect “deniers” are to the skeptical side of the debate.
Sadly, those hard core warmists still have their side adequately and completely inappropriately represented by the hottest running broken GCMs, which the IPCC and CMIP5 people have stubbornly resisted removing from the multi-model ensemble mean that the use to make predictions, assign confidence intervals and generally maintain the panic. This is a shameful thing, and one day all of science will have its reputation tarnished if — as seems increasingly likely — the planet experiences distinctly non-catastrophic warming due to even a doubling of CO_2 or worse, if net feedback indeed is negative, natural variation has been more than half responsible for the late 20th century warming spurt, and natural cooling outweighs the small marginally positive warming the Earth might have experienced from the additional CO_2 as the climate proceeds to continue its slow trajectory towards an expected but ill-understood glacial transition and the nice, warm Holocene comes to an end.
In a sane universe, there would be no warmists, no skeptics. The very terms are direct evidence that science itself has run deeply awry. All scientists should be skeptics. No scientist should ever display so much bias towards some particular theoretical prediction being correct (especially in what has to be the most difficult set of theoretical computations humans have ever attempted, computations that reach the envelope of what is possible with no prior experience to validate any aspect of the results) that they could legitimately be called “warmists” because they hold onto the theoretical predictions as being more probably true than reality itself even as evidence accumulates that they are completely wrong.
One day soon — maybe — nature will resolve the matter. Maybe in years, maybe in decades. Eventually either it will have deviated so far from the theoretical predictions that no rational scientists can “deny” that the GCMs are badly broken and that climate sensitivity is low and within the bounds of natural variation or that broken GCMs or not, the climate is definitely warming at a potentially catastrophic rate in the long run, with a warming signal that does indeed outweigh natural variation. At the moment, there is literally no way to disentangle natural warming or cooling trends from a CO_2 driven component. In a strongly coupled, nonlinear, chaotic system there may never be! At least, none that we can ever reliably compute.
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Stern doesn’t want ABC to see what he’s up to in the background. Does here really care about global warming or something ‘green’ that rides on the back carbon? No wonder he want action to ‘tackle’ climate change.
http://wattsupwiththat.com/2014/03/28/matt-ridleys-new-article-in-the-wsj-a-dose-of-pragmatism-about-revelations-from-the-new-ipcc-report/#comment-1600311

Col Mosby,
“Coal has dropped in importance and is now 66% and will be 44% by 2030, the same as the U.S. ”
No, you cannot say what it will be in the future, only what it is now and has been previously. Anything else is just wishful thinking.

“high-carbon capital and infrastructure gets locked in. ”
Is this code for “we will regulate to make industry leave the fossil fuels in the ground?”

F.A.H. says:
March 28, 2014 at 7:42 am
” reference to a cavalier dismissing as an outlier anything that does not agree with your pre-conceived notion. I am thinking of modifying the joke the next time to replace the astronomer with a climate scientist.”
Or, more accurately, to an Economist with a wish to sit in the House of Lords.”

I think the ABC presenter let Stern get away with murder! It was like watching the BBC having a cosy love me-love you chat with the leader of the Lib-Dem (i.e. Liberal) Party. The Chinese are rapidly increasing their coal production to lessen their imports – factual common sense. They say they will reduce their “consumption” of coal in about 10 years time – wishful thinking and highly unlikely!

According to Rupert Darwall in The Age of Global Warming, it was China that derailed the 2009 Copenhagen Conference – because they weren’t about to compromise their development plans for the sake of an agreement on Global Warming. Darwall also wrote that China’s chief climatologist , or at least the main govt advisor on the topic, had already told the Chinese officials not to worry too much about AGW. So I suspect that while China may be willing to attend meetings, and even talk up renewables, their energy policy including use of coal is not affected by any attempts to reduce CO2. They may also have other reasons to improve their energy mix such as reducing (real) pollution.

As has been said by many a smart observer, civilization advances one funeral at a time. It is surely past time for Lord Stern’s, to ensure the greater good, is it not?