Discussion > We are wasting our time; all of it.
Martin A
Something I would like to know:
Has a comparison been made between top of atmosphere radiation detected when the sun is shining directly on the ground beneath the satellites and the radiation detected when the sun is 'behind' the earth?
Dung
Dung - interesting question. I can imagine various reasons why such comparisons would have been made but it's not something I have ever come across.
Ask Entropic Man - he sucks up that sort of information like a vacuum cleaner.
Martin A
…very non-zero probability of dangerous change…One gets the impression that any change is going to be “dangerous”. How the definition of “dangerous” is determined should be interesting, especially if the present plateau turns out to be a peak, and temperatures plummet (now, that could be dangerous!).
Radical Rodent
Raff (Jun 12, 2015 at 3:06 PM):
"The forcing from a doubling of CO2 of around 4W/m2 (or 3.7 actually) is also universally agreed."
Not quite. When I first started looking at the science, I thought that. After all, radiative balance equations are straightforward enough to solve accurately. So it made sense that this would be a rock-solid fact.
As it turns out, even this aspect of the science is squishy. Forster et al. (2013) examined doubled-CO2 forcing from 20 or so models and came up with 3.44 +/- 0.84 Wm-2, with a range of 2.59 to 4.31.
HaroldW
Martin, I can't see "spatial mean of the global temperature field" catching on.
Radical, I've never seen anyone saying that "any" temperature change is likely to be damaging. That would be silly. Do you have a physical mechanism in mind that would make the spatial mean of the global temperature field plummet?
Harold, the forcing the paper states as 3.44 is referred to as the "adjusted forcing", not the radiative forcing. They also find a mean ECS of 3.22+/-1.32K (TCR 1.82+/0.63).
Raff
Neither have I, but the implication is certainly there, with all sorts of Chicken Littles assuring us that “it’s worse than we thought!” (look in a mirror, if you are wondering if I could mention an example). As the worst rate of rise that can be claimed is about 0.8°C per century (i.e. one that can be proven to have occurred, thus can be considered as a plausible future rate), one has to wonder quite how much of that 0.8° will take us into “dangerous” territory.
Do I have a physical mechanism in mind that would make the spatial mean of the global temperature field plummet? No. But I do not discount the possibility that one could exist that neither I nor anyone else is aware of; however, there are those who do point out that solar irradiance is falling, and, as the Sun is our principle source of energy, this could be a possible physical mechanism. Can you assure us that there is no physical mechanism that can cause falling temperatures?
Radical Rodent
Dung
"Has a comparison been made between top of atmosphere radiation detected when the sun is shining directly on the ground beneath the satellites and the radiation detected when the sun is 'behind' the earth?"
OLR peaks around midday and troughs at night. The change is visible, but not massive, about 5%.. Look at Figure 2 here .
Entropic man
Radical, I don't think you'll find any examples of me saying "it's worse than we thought!" or anything similarly unequivocal. My concern is entirely based on the uncertainty - that there appears to be significant possibility of a big rise in the spatial mean of the global temperature field (SMotGTF).
The 0.8°C per century you quote is for a century in which emissions started low and ended high. Even if you think the full effects of those emissions have already been felt, this century is guaranteed to follow a different path (because emissions are already 'high').
If you know of no mechanism that would cause SMotGTF to plummet, it is illogical to worry about such an outcome - unless you know for certain that this unknown process is more likely to push SMotGTF suddenly negative than suddenly positive. Especially when an exiting mechanism is known to be pushing SMotGTF higher. Solar insolation is cyclical varying by about 1 W/m2. I don't think it has declined by more than 1 W/m2 from its peak, and even if it remains depressed (low numbers of sunspots) that change is only 1/4 of the expected forcing from doubled CO2. Again, it is illogical to worry about a 1W/m2 fall and not about a 4W/m2 rise. Skeptics like to say that climate is insensitive to forcing and yet you think a 1W/m2 fall is a worry. I guess you can justify your concern but it escapes me.
Can you assure us that there is no physical mechanism that can cause falling temperatures?No, of course not. Clearly a sustained drop in solar insolation will do it. (Oddly, those like hand-grenade Jim (Big Yin) who think sensitivity is negative would presumably have to expect rising SMotGTF in such circumstances.) Amusingly the solution to both the risk of rising and falling SMotGTF could be the same: not burning fossil fuels. This both reduces the risk of causing rising temperatures and keeps those carbon fuels in-hand to be burned if necessary.
Raff
"Do I have a physical mechanism in mind that would make the spatial mean of the global temperature field plummet?"
What physical mechanism caused The Little Ice Age?
Big Oil
"The more you talk up uncertainty, the more you emphasize the very non-zero probability of dangerous change that you want to deny.."
I'm not sure you're getting this Raff. I don't believe anyone knows, or can know, the future state of the climate, so for me everything is on the table from "benign" to "dangerous" with the same probability. If every event has the same probability it would, and is, inadvisable (o prepare for the worst probability, especially as there are other confounding variables like the increase in human wealth (10 to 70 times according to the IMF) and technology (whose to say that cold fusion won't become a reality in the next few decades). What the "inaction" faction have on their side are:
No records of any runaway temperature increases in the paleoclimate records associated with rises in CO2;
The Oceans never having been acidic since their formation despite having CO2 levels 10 times higher than today.
Sea level rises will take centuries.
The absolute certainty that another ice age will arrive in the next few thousand years.
But we, none of us, know what will happen in the future even if the tails, as they are get thinner and thinner, the future state of the climate cannot be modelled, or foretold, by either side of the debate.
geronimo
Big oil
Little Ice Age?
Milankovich cooling plus high volcanic activity.
Entropic man
I don't think you'll find any examples of me saying "it's worse than we thought!" […]Surely, two contradictory statements? You are concerned about the uncertainty, as you fear that it is going to be… well… worse than we thought.My concern is entirely based on the uncertainty - that there appears to be significant possibility of a big rise in the spatial mean of the global temperature field (SMotGTF).
Yes, you are right – there is an awful lot of uncertainty out there; in fact, so much that there is little we can do to predict which way any of it will go. This is the problem that a chaotic system throws at us. Unfortunately, it would seem that the majority of the human race does not like uncertainty, and will do anything to make it more certain. They used to fling virgins into volcanoes for that sort of thing, in the not-so-distant past. Also, there always has to be a cause for the uncertainty. Whereas it used to be the behaviour of individuals: what they said or did, or their non-compliance in performing the correct rituals, say, or of stripping off on top of a mountain, or otherwise angering "the gods", now we can have “scientific” explanations – in this case, rising CO2. And what causes the CO2 to rise? Well, “science” has determined that it is the human burning of “fossil” fuels, as it can find no other reason, utterly ignoring the fact that they haven’t actually looked for any other reason. Quite why the fact that, while burning of fossil-fuels has risen exponentially, the rise in CO2 has been more or less steady seems to have passed by those who determine what is “valid” and what is not has to be a mystery.
I do not worry that the SMotGTF (yes, I like that term, even though there is no way to actually determine it, yet) will plummet, though I might fear that it will, as it will cause a lot more disruption than the considerably more benign option of it resuming its rise. However, we return, as always, to the point that, while we accept that we live in a totally chaotic system that is the general climate of this planet, you remain convinced that there is just one mechanism that is influencing it, and that is – coincidentally – a mechanism (perhaps the only mechanism) that humans have a perceived influence over. While I can accept that bizarre coincidences can happen, this one seems to me to be a little too, erm… convenient. Add to that the incredibly shaky evidence and the associated shonky “science” adjusting evidence to fit the theory, and you get a good summation of my scepticism.
Radical Rodent
geronimo
I agree with the 'gist' of your post but not this one statement:
The absolute certainty that another ice age will arrive in the next few thousand years, I would change this to:
The absolute certainty that our inter glacial will end in the next few thousand years
However we could equally likely either begin to warm to the Earth's most common warmer climate or as you say and most likely in my opinion; return to ice age.
Dung
Radical Rodent above alludes to 'Shonky Science' ; he is right and I don't understand why (when looking for explanations about and predictions for climate) people go to the current scientific theories. A climate scientist today who is trying to predict climate is about as reliable as a witch doctor throwing his bones on the ground and 'interpreting' their meaning.
Currently there is now way for us to predict climate but there IS a reliable guide out there and it is geological evidence.
When you have a geological record of 700,000 years during which rising CO2 never once caused temperature to rise, what person in his right mind would suggest that this is now happening for the first time in recorded history?
People like Gavin Schmidt from NASA are well aware of this inconvenient (Real Climate) truth and there are well qualified scientists who have written 'explanations' on RC website. IF you want to see really really SHONKY science; read this example (my emphasis):
"This is an issue that is often misunderstood in the public sphere and media, so it is worth spending some time to explain it and clarify it. At least three careful ice core studies have shown that CO2 starts to rise about 800 years (600-1000 years) after Antarctic temperature during glacial terminations. These terminations are pronounced warming periods that mark the ends of the ice ages that happen every 100,000 years or so.
Does this prove that CO2 doesn’t cause global warming? The answer is no.
The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data.
The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming.
It comes as no surprise that other factors besides CO2 affect climate. Changes in the amount of summer sunshine, due to changes in the Earth’s orbit around the sun that happen every 21,000 years, have long been known to affect the comings and goings of ice ages. Atlantic ocean circulation slowdowns are thought to warm Antarctica, also.
From studying all the available data (not just ice cores), the probable sequence of events at a termination goes something like this. Some (currently unknown) process causes Antarctica and the surrounding ocean to warm. This process also causes CO2 to start rising, about 800 years later. Then CO2 further warms the whole planet, because of its heat-trapping properties (er um, any proof for this????). This leads to even further CO2 release. So CO2 during ice ages should be thought of as a “feedback”, much like the feedback that results from putting a microphone too near to a loudspeaker.
In other words, CO2 does not initiate the warmings, but acts as an amplifier once they are underway. From model estimates, CO2 (along with other greenhouse gases CH4 and N2O) causes about half of the full glacial-to-interglacial warming.
- See more at: http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores#sthash.EG5Z02ul.dpuf
Dung
Dung - I think the Rodent may be a she-mouse.
Martin A
"(whose to say that cold fusion won't become a reality in the next few decades)."
I'll put a couple of grand on it.
When I read the original news report it seemed to me at once it was bollocks. (How come they
were still walking about and not on life support, having been close to their unshielded apparatus which had supposedly produced measurable amounts of heat?).
But I imagine that some of the big names of fusion research may have passed a couple of disturbed nights wondering if all their inertial confinement equipment had been outdone by something as simple as a palladium electrode in a pyrex flask of heavy water. So at least some good may have come of it.
I'd also put a couple of grand on hot fusion not coming to anything usable.
Martin A
Martin A
I am reliably informed that the true identity of RR is in fact the brains behind the famous Danger Mouse; PENFOLD!
Dung
Dung
Your link didn't work for me. This did
Entropic man
Now, that is clutching at straws! Whereas I am reluctant to leap to conclusions about the fracking “blow-out” as I do not have enough information, RealClimate seems determined to leap to a conclusion of their own favourite choice (i.e. it fits the theory), despite the plethora of evidence presented. I do not consider myself a “scientist”, but do like to think I can be scientifically-minded; these folk do consider themselves scientists, but display alarmingly non-scientific thinking. What alarms me even more is that they expect no questioning of their conclusions just because they are “scientists”!
Radical Rodent
Geronimo, why do you write such things? Runaway temperature increases are a straw man, the oceans can easily buffer increases in CO2 if change is slow (which it currently is not), sea level rise may take centuries or it might be quicker - you don't know - and there is no certainty of a new "ice age" in "the next few thousand years" (the very few examples few have from ice cores seem to last between a geological blink and tens of thousands of years).
Radical, when you contemplate temperatures "plummeting", what sort of rate do you have in mind? Looking at ice core plots the fastest change, which appears to be on the rising edges, seem to be about 10K in 5000 years or 0.2K per century. So why does this potential snail's pace of change concern you when the rate of rise is currently around 5 times higher?
while we accept that we live in a totally chaotic system that is the general climate of this planet, you remain convinced that there is just one mechanism that is influencing it...Where did I say that? If you are going to make things up, try to make them at least plausible.
Dung,
When you have a geological record of 700,000 years during which rising CO2 never once causedyou infer from this that rising CO2 cannot cause temps to rise. Ignoring feedback, all your 700K year "recorded" history shows is that there has never been a spontaneous rise in CO2 followed by a temp rise. It says nothing about what would happen if CO2 were to rise as it is doing now. It is an empty statement.
temperature to rise...
Raff
… if change is slow (which it currently is not)…So, what is “slow”, and what is not, at present rates of change? And how can you state with such confidence that present rates are NOT slow?
… you remain convinced that there is just one mechanism that is influencing it...You have certainly been giving a very strong impression that you believe that it is only CO2 that is causing present “climate change” – or, more specifically, CO2 produced by humans burning fossil fuels, such that, merely by changing our habits of burning fossil fuels, we can halt climate change. Are you now saying that we are wrong coming to that conclusion? What other mechanism do you think might be involved?Where did I say that?
As the accepted average change of temperatures that has been identified in palaeological records is about 1°C per century, a “plummet” would then be at a greater rate than that (say, at >0.2°C – or >0.2K, which might be your preference – per decade), as happened at the end of the mediaeval warming period (MWP), when the drop into the little ice age was quite dramatic. Regrettably, palaeological records do not allow to determine rates of change over periods of less than a few centuries, so we are, and will probably forever remain, ignorant of any short-term trends in times long past.
You will now start to nit-pick this in infinite detail, in your desperate efforts to prove yourself superior, little realising that virtually every statement you make is empty to the point of vacuous. You really are a tiresome little twerp, Raff, and discussion with you is truly, truly a waste of everybody’s time.
Radical Rodent
Raff (Jun 14, 2015 at 10:02 PM),
Yes, Forster et al. present adjusted forcings (AF). But surely the point is that RF alone, even if it could be precisely quantified, is of little value, hence the introduction of ERF (effective radiative forcing) and AF. "ERF [is] a better indicator of the eventual global mean temperature response." [AR5 WG1, Box 8.1] To return to the narrower topic of RF, AR5 wrote, "...the uncertainty range from AR4 in the RF of GHG of 10% is retained. We underscore that uncertainty in RF calculations in many GCMs is substantially higher owing both to radiative transfer codes and meteorological data such as clouds adopted in the simulations." [AR5 WG1, para 8.3.1]
As for the GCMs' ECSs, I think we're all aware of their range. I think we're all aware also of the discrepancy between the temperature predictions of the models, and Mother Nature's solution to the climate equations. In the words of James Annan, "It's increasingly difficult to reconcile a high climate sensitivity (say over 4C) with the observational evidence for the planetary energy balance over the industrial era."
HaroldW
Harold, yes point taken. But I'm not sure it makes a lot of difference to the arguments whether it is 3.4 or 3.7
Radical, slow or fast? Slow would be maybe doubling CO2 over a million years with time for the oceans to adjust. Fast is doubling in a few centuries.
On influences, I quoted from you:
while we accept that we live in a totally chaotic system that is the general climate of this planet, you remain convinced that there is just one mechanism that is influencing it...Your trailing 'it' is general climate. I've never said there is just one influence on climate. If you want to fabricate what I say, be a little intelligent about it and don't rely on partial quotes.
The MWP to little ice age transition seems to be less than 0.5C shift globally in several centuries. If you think that is "dramatic" or qualifies as "plummeting", then I'd expect you to think that recent temps have shown dramatic rises. But no, of course.
Raff
Raff -
The second part of your last post (11:47 PM) is addressed to me, but those are not my words. Must have been some other interlocutor; I'll let him or her respond.
HaroldW
OK Raff - points noted.
Except that I think that there is no such thing as "true global mean temperature".
There is an infinity of ways of defining an average of the temperatures measured at every point on the Earth and the choice of definition is arbitrary. So, for that reason alone, there is no one "true global mean temperature". If there were one that gave a direct measure of total atmospheric energy, that would be very handy - but there is not.
There is also the point that, physically, an average of temperatures is not itself a temperature, so I would reject the term "true global mean temperature", although I could live with a term such as "spatial mean of the global temperature field" or something like that, even though it's a mouthful.