Radiative transfer models show that adding more CO2 to the atmosphere doesn’t have much affect on temperature, so Hansen made up a psychotic theory of positive feedbacks, which were going to push the Earth past a “tipping point.”
The most important feedback was loss of polar sea ice, which was theorized to amplify global warming. This hasn’t happened. In fact the amount of sea ice on Earth may challenge record levels later this year.
If positive feedbacks dominated, Earth would have passed many tipping points in the past. But like all long standing systems, negative feedbacks dominate and keep the climate relatively stable.
All real scientists understand this, which is why climate scientists don’t.
The “Arctic Ice Albedo” feedback is pure baloney for a number of reasons:
1) Yes seawater is darker and will absorb more sunlight than ice/snow, but the arctic is in darkness much of the year, and the insolation there is is very oblique.
2) Removing Arctic ice allows 14 billion sq metres of now open ocean to radiate tens of W/m^2 to space. And the Atlantic circulation will keep feeding the warmth there to radiate, so removing the ice will cool the planet.
3) Ice insulates the heat of the ocean from the air. Arctic ice warms the planet it doesn’t cool it.
4) Extra evaporation from open sea increases the humidity, meaning more snow ( and eventually Ice). The whole thing is self-regulating.
The Arctic is the world’s thermostat. It opens to release heat, and closes to retain it, just like the thermostat in a car.
There is only one tipping point in climate, and it is in the other direction…
https://www.youtube.com/watch?v=WNmVVddrU2g
I have often wondered if one climate extreme generates change towards the other extreme. In the case of snowball earth, I have pondered if the insulation provided by the solid snow/ice cover actually leads the ocean waters under the ice to gradually heat up due to the thermal warming of the vents from the crust adding heat which can’t escape through the surface and out into space. Eventually a tipping point is reached where the warmer water from below melts the ice above and a new movement towards equilibrium takes place. Just some random thoughts.
One of the wonders of physics is that when liquid H2O becomes a solid, it expands and floats on top of the liquid form, insulating the liquid H2O beneath. Without this property, life would have been much more difficult, if not impossible, on this planet.
This would be similar to plate tectonics on Venus….no?
I like those little saw tooth graphs of CO2 and temperature.
The prove categorically that even when CO2 had been at its highest level, it was totally unable to even maintain the warmer temperatures that released that CO2.
The peaks in CO2 always coincide with the start of falling temperatures.
https://youtu.be/bJ55koi7vaA
I am sure everyone has heard the phrase ‘Dead man walking’
The ‘Arctic regulator’ is crappy.
It goes super cold for 100,000 years at a time and then suddenly goes very warm for 20,000 and then back into the super cold for another 100,000 years.
Liberals can now go jetsetting up to the Russian base called “Barneo” (where the scientists who deploy the “North Pole Camera” reside) for a mere $15,000, and do some cross country skiing, with a helicopter available to rescue them if they get frostbite. Back at the dining room at Barneo they can discuss the “arctic death spiral” while eating veal cutlets around sixty miles from the Pole, (because the ice drifts away from where the base is initially erected in March.).
This year they ran into a bit of a problem as the landing gear of one of the jets collapsed. I figure they have around 45 days to get the jet fixed before the ice starts getting slushy during the summer melt, and taking off becomes impossible.
https://sunriseswansong.wordpress.com/2015/04/13/jets-landing-gear-fails-at-pole/
If the Pole is melting, why do they plan an entire tourist trade around jets landing up there in April?
The whole positive vs negative feedback balance has always been one of my biggest issues with the whole AGW theory.
If a system (in this case, the Earth and its energy balance) is subject to cascading positive feedback effects (for either cooling or warming), then you’d eventually see it settle in a steady state at either end of the spectrum.
The fact is that we’re not in a “Venusian hothouse” or a “Snowball Earth” state indicates to me that the Earth is a balanced system and all of the tipping points lead here.
The Earth is basically in a Steady State, which means that the feedbacks led us here. Forcing changes are mitigated by negative feedbacks.
Warmer temperatures means more global snow albedo, more cloud cover, more heat radiated to space, etc. The opposite for cooling effects.
I’m not trying to make the case that we’re in a never-changing Eden, something the AGW crowd seems to believe we have achieved and should therefore strive to maintain. I just believe the Earth has been around a long time and has had a LOT of opportunities for tipping points.
This is not to say that we have not had warmer periods and Ice Ages. But I think the forcing effects for the cyclical changes in the last million years or so have been external to the planet. There seems to be no record of terrestrial changes that could have precipitated these changes.
It’s plain from the temperature graphs of the last few million years that we’re in a bi-modal feedback loop, with the warming feedbacks operating much faster than the cooling ones, but being much less stable. By all accounts, we’re currently at the upper historical limit, give or take a degree or two. This limit has been tested dozens of times in the last 3 million years, and has yet to fail. In fact, both limits are trending downward.
When you ask what has caused the previous shifts, the almost universal answer is “Milankovitch cycles.” That said cycles are entirely inadequate to cause the temperature changes is explained away as proof of feedbacks. But I’ve yet to hear an explanation of how those feedback are overcome, at the top and bottom of the cycles. Orbital eccentricity starts a feedback loop which then becomes utterly dominated by CO2. So how, once the effects of CO2 dwarf the eccentricity, does eccentricity once again pull the temperature back down? Clearly something else is going on here. CO2 dominates until, suddenly, it doesn’t anymore. Can anyone point me to a theoretical cause of that shift? Seriously, no one has ever even offered me a hint.
On a somewhat separate note, can anyone explain why feedbacks from human causes are supposed to be positive, but no other feedbacks are? If Eemian temperatures were warmer than today, as is usually assumed, but CO2 was lower, shouldn’t that have caused an even stronger positive feedback than today? All the currently suggested feedbacks should have been in place, but with more room for CO2 heating. My understanding is that it’s the temperature change, and not the CO2 level, that should produce the feedbacks. Methane hydrate deposits don’t care where the heat to melt them came from. Eemian temperatures were warmer than most of the numbers I’ve seen for the alleged tipping point. Am I missing something?
I started out having little opinion on global warming, either way. But when I started asking the warm mongers these questions, all I ever got was, “shut up, you evil, anti-scientific, moron.” I’m (barely) old enough to remember first hand the 1970’s ice age scare. Now I’m told the exact opposite, and that the debate is over. But I’ve been paying attention this whole time. I don’t remember any debate. If the science is settled, why can’t anyone point me to it?
Mornin’ Ted,
“It’s plain from the temperature graphs of the last few million years that we’re in a bi-modal feedback loop, with the warming feedbacks operating much faster than the cooling ones, but being much less stable. ”
Exactly. See my post up the page. IMHO the main feedback loop is the Arctic ice-cap. It freezes over and heat builds up rapidly as it can no longer radiate to space (It’s insulated by the ice). Rapid heat build-up results (say at 150ka in this plot):
https://en.wikipedia.org/wiki/Temperature_record#/media/File:EPICA_temperature_plot.svg
Then at ~120Ka the heat has built up enough that the ice is melted gradually from below, first 5% for a few centuries, then 10% the next few; enough as is necessary to release the heat via the “arctic thermostat”.
As the heat is being released, there’s more open ocean –> more evaporation –> more snow/ice and eventually 20ka we have an arctic icecap again. .
Guys, guys… and Gals…
We’ve lost the Debate at the Geo-Political Level… be quiet and pay your Tax.
Reblogged this on Centinel2012 and commented:
The very fact that we are here means there are no positive feedback that dominant the climate. CO2 has been in the past much higher than it is now.
“…so Hansen made up a psychotic theory of positive feedbacks, which were going to push the Earth past a “tipping point.””
An apt characterization – Hansen is either kidding himself (crazy like a fox), or possibly just insane. Over the years, and some of the crazy stuff he has said, I am beginning to think he is just crazy.
CO2 Climate Science predicted a temperature rise solely from Man-Made CO2. And it fails to warm up in accordance with models. On balance, we should expect to see some warming from the added CO2 if it’s insulating qualities are as claimed. In other words, it wouldn’t surprise me at all if it were hotter – could be some unknown poorly understood mechanism; could be CO2; but a little warmer? Meh…
But it isn’t getting warmer. This is interesting. Why isn’t it getting warmer? I think that is an interesting question. I think it is an interesting question outside the whole “Climate Science” debate. It suggests at least a couple of things – there is an upper-limit to earth’s temperature (?); there are strong negative feed-backs countering the added mole-fraction of CO2; solar correlations just seem to close to be coincidence; but by precisely what mechanism? Can we forecast climate? I’m not so sure. We certainly haven’t done a good job of that!