From ETH Zurich: Underestimated future climate change?
25.11.2013 | Fabio Bergamin
New model calculations by ETH researcher Thomas Frölicher show that global warming may continue after a stoppage of CO 2 emissions. We cannot rule out the possibility that climate change is even greater than previously thought, says the scientist.
Many scientists believe that global warming will come to an end if, some day, human succeeds in stopping the release of greenhouse gas emissions into the atmosphere. It would, indeed, be hotter on Earth than before industrialisation, but nonetheless it would not get even hotter. Climate physicist Thomas Frölicher questions this notion by using model calculations and creates a more pessimistic picture in a study published in the scientific journal Nature Climate Change. According to his model calculations, it is very possible that the Earth’s atmosphere could continue to warm for hundreds of years even after a complete stop of CO2 emissions, and that temperature levels stabilise at an even higher level at a later stage.
“In the long term, the temperature increase could be 25 per cent greater than assumed today,” says the scientist, who carries out research as an Ambizione Fellow of the Swiss National Science Foundation in ETH professor Nicolas Gruber’s group.
A more realistic model
Frölicher and his co-authors from the USA use one of the world’s leading climate models for their calculations, the ESM2M model that was developed at the Geophysical Fluid Dynamics Laboratory in Princeton. It represents physical and biogeochemical processes – such as the exchange of greenhouse gases and heat with the oceans – at a far more detailed level than many previous models. “The model is closer to reality,” summarises Frölicher.
In this model, the researchers simulated an Earth on which 1800 gigatons of carbon are emitted instantaneously into the atmosphere. By way of comparison: 1000 gigatons are believed to lead to a global warming of 2 degrees Celsius. Frölicher’s model calculation corresponds to an extremely simplified scenario. In reality, greenhouse gases are released over a period of several decades or centuries. The simulations, however, are well suited to illustrate fundamental principles, explains the climate scientist.
Regional ocean heat uptake is the key
“Much of the CO2 released into the atmosphere and the heat trapped by the CO2 goes into the ocean sooner or later – approximately 90 per cent of the excess heat has been taken up by the ocean over the last 40 years,” explains Frölicher. The regional uptake of heat, however, is crucial. To date, not enough attention has been given to the regional heat uptake of the world’s oceans in climate research. With the help of the ESM2M climate model, the scientists are able to show that a change in ocean heat uptake in the polar regions has a greater effect on the global mean atmospheric temperature than a change near the equator. The researchers use these differences to explain why their calculations contradict a scientific consensus that global atmospheric temperature would remain constant if emission were suddenly stopped.
Frölicher acknowledges that his calculations are based on a single climate model and it should not be ruled out that different results might be obtained if other climate models are used. However, it is evident to him that the magnitude of global warming in the next few centuries is less clear than previously thought. Rather, we should consider that climate change could turn out to be even greater than we have thought until now, says the scientist. “If our results stand up to a repetition with other modern and detailed models, this would mean that global warming considered beyond the end of this century has been significantly underestimated to date.”
A 25 per cent increase in global warming would also mean that humans could release 25 per cent less greenhouse gases to achieve climate goals such as the two-degrees Celsius target. In its assessment report published a few months ago, the Intergovernmental Panel on Climate Change IPCC assumes that limiting the global warming to less than two-degrees Celsius will require cumulative CO2 emissions to stay below 1000 gigatons of carbon. Since preindustrial times, humans have already consumed around half of this budget, i.e. 500 gigatons. If Frölicher’s results were correct, the “emissions cake” would be only three-quarters, i.e. 750 gigatons instead of 1000 billion tons of carbon. Thus, limiting the warming to 2 degrees would require keeping future cumulative carbon emission below 250 gigatons of carbon, only half of the already emitted amount of 500 gigatons.
Literature Reference
Frölicher TL, Winton M, Sarmiento JL: Continued global warming after CO2 emissions stoppage. Nature Climate Change, Adavance Online Publication 24 November 2013, doi: 10.1038/nclimate2060
A 25 per cent increase in global warming? Would that be 375degK ? – OH. only 2degK increase. Never mind.
I cannot rule out the possibility that my granny is a wagon.She hasn’t sprouted wheels just yet, but anything is possible, eh?
More likely she is a horse. Four major appendages already extant. Almost anything is possible. No?
“Hang on… Every time I point out to people that the Earth has had far more CO2 in the past, the universal response has been “yes, but that happened gradually, today it is happening rapidly”. That, according to every warmist I have encountered, has been the CRITICAL difference. ”
Yes, but I don’t know why it makes a difference. The hypothesis of greenhouse gases is based on their concentration, not the time it took to get there. It’s just another way of moving the goal posts.
As a graduate of the ETH this saddens piece me tremendously. The Department of Physics used to be home to people like Wolfgang Pauli, and Albert Einstein, now there is the sad image of “progressive” science taking them back to before the age of reason.
It is a million light years away from science.
Insufficiently distant.
If the heat/energy is hiding in the ocean wouldn’t we note the transport of said heat/energy?
So how dd it get there?
I’m waiting.
Eliza says:
November 25, 2013 at 5:33 pm
I am surprised that WUWT would want to give any attention to drivel like this
Entertainment value.
“A change in ocean heat uptake in polar regions has a larger effect on global atmospheric temperature than a change at low latitudes. A fact that has not been given enough consideration until now.”
This should have been published on April 1st. The only heat uptake to the Arctic ocean that is worth considering is from transport of warmer sea water from further south when the AO/NAO are more negative, and the AO/NAO are more negative in *global cooling* episodes.
The Arctic ocean didn’t do so well on heat uptake from the atmosphere this summer lol:
http://ocean.dmi.dk/arctic/plots/meanTarchive/meanT_2013.png
“M Simon says:
November 26, 2013 at 3:47 am
If the heat/energy is hiding in the ocean wouldn’t we note the transport of said heat/energy?
So how dd it get there?
I’m waiting.”
So is Trenberth but his computer game will just not comply!
I’ve often wondered how the seas were getting warmer.
I would have thought that even a 1 degree increase in air temperature wouldn’t do a great deal, particularly as only the first few metres at the surface would be warmed via conduction from the air. As water is denser than air, it would take a long time to get the sea temperatures to match.
Given that water takes hundreds if not thousands of years to circulate from the depths of the deepest oceans to the surface, using air temperature to warm the seas would be an inefficient solution. Whereas infra-red can penetrate several hundred metres depth and is possibly a far more effective way of warming the oceans.
If the sea (mostly) and not the air is melting the sea ice, this may also explain why the Arctic sea ice is melting rapidly (because the water is getting warmer) and the Antarctic land ice isn’t melting rapidly.
Now, if more infra-red is being trapped by the carbon dioxide in the atmosphere via MMGW you would logically expect that less IR would be reaching the oceans, especially if you assume that the rate of infra-red is constant, so the oceans should actually be cooling or at least not warming.
Unless, either the carbon dioxide is being dissolved into the water (when you would expect completely the opposite to happen – gasses escape as the temperature increases) or there is an increase in infra-red.
Is it me (in genuine ignorance)? Or can anyone explain this conundrum?
New model calculations by ETH researcher Thomas Frölicher show that global warming may continue after a stoppage of CO 2 emissions. We cannot rule out the possibility that climate change is even greater than previously thought, says the scientist.
Still stuck on stupid only this far in.
I stopped reading after the 2nd mention of ‘models’. Yawn. Okay show us all of your data sets, algorithms, data models, data base diagrams, assumptions, E-R diagrams and syntax. Make it public now. I want to see your entire IT application build and review your Stats methods. Oh, you don’t provide such info – yet this is what the warmtards call ‘science’ ? Laughable.
So here’s a question for the authors. If this model is “closer to reality”, then it has accurately (within 1 sigma) simulated and EXPLAINED the current 17 years of NO WARMING? Show us please.
This ocean heat uptake at the polar regions is having a devastating effect on Antarctica. It has lead to growing extent since the 1980s and extreme snowfalls in Eastern Antarctica. It’s still bloody cold too. As for the Arctic we have see a tiny, tiny growth of sea ice this past summer on 2012. Record cold since 1958 above 80 degree north. It really is much, much worse than we thought.
Owen in GA says:
November 25, 2013 at 8:05 pm
GIGO – Garbage In Garbage Out. I often see this statement used on WUWT in the context of AGW computer models. In a computer programming class a professor explained there is something far worse than GIGO. And that would be GIGO – Garbage In Gospel Out.
If the “heat” is driven into the cold ocean below the several-hundred-meter level, it’s diffused & gone into oblivion.
Gil Dewart says:
November 25, 2013 at 5:17 pm
Way back in the 1990s, a CACA advocate claimed that we might still be in the Little Ice Age, & that only human GHG emissions were giving the appearance that we’re coming out of it. So, naturally, what we’re doing is much worse than we thought.
If it happens is essential here: A change in ocean heat uptake in polar regions has a larger effect on global atmospheric temperature than a change at low latitudes.
As both poles seems to gain ice it is very possible that the poles loose heat, so it will be a lot colder on the globe in the future.
RobR: I totally agree. When I write a model, I then compare it with the real world thing it is meant to represent. When it agrees, I am happy and look for things the model might predict that I can then look for in the real world. When the prediction doesn’t match, I go back to the code assumptions and see what I did wrong. By definition, only the real universe is correct – our understanding of it is only a dim echo seeking affirmation.
“It represents physical and biogeochemical processes – such as the exchange of greenhouse gases and heat with the oceans – at a far more detailed level than many previous models. “The model is closer to reality,” summarises Frölicher.”
and
“Frölicher’s model calculation corresponds to an extremely simplified scenario. In reality, greenhouse gases are released over a period of several decades or centuries. The simulations, however, are well suited to illustrate fundamental principles, explains the climate scientist.”
“Far more detailed” and “extremely simplified scenario”. If these ARE both true, then the previous models must have been poor indeed. OR, we’re seeing more GIGO…
I also have to wonder what he was “fröhlicher” (glad, merry, happy, etc.) about? More grant money, perhaps?
“If our results stand up to a repetition with other modern and detailed models, this would mean that global warming considered beyond the end of this century has been significantly underestimated to date.”
Since the Fecal Interrogative was already taken, I guess I am left with
“Oh my goodness gracious!”
So….. GFDL-ESM2M means:Go For Da Loot ! Emergency!Send Money 2 Me!
We cannot rule out the possibility that climate change is even greater than previously thought, says the scientist.
Yes, this explains why warming has stopped for some 17 years, and counting. The CO2 has simply switched to “climate change” mode.
“Climate physicist Thomas Frölicher questions this notion by using model calculations and creates a more pessimistic picture ”
As long as they have models they will never run out of papers to write; and never discover anything.
This must be the perfection of uselessness. Watch squiggles on screen, apply for grant, get a Caramel Frappuccino Extra Grande, copy & paste text from last paper, replace squiggles, publish, ka-ching, repeat…
The comment “Worse than we thought” sums up the state of climate science…it’s a laugh a minute at present.