From the University of Cambridge
Many of the complex computer models which are used to predict climate change could be missing an important ozone ‘feedback’ factor in their calculations of future global warming, according to new research led by the University of Cambridge and published today (1 December) in the journal Nature Climate Change.
Computer models play a crucial role in informing climate policy. They are used to assess the effect that carbon emissions have had on the Earth’s climate to date, and to predict possible pathways for the future of our climate.
Increasing computing power combined with increasing scientific knowledge has led to major advances in our understanding of the climate system during the past decades. However, the Earth’s inherent complexity, and the still limited computational power available, means that not every variable can be included in current models. Consequently, scientists have to make informed choices in order to build models which are fit for purpose.
“These models are the only tools we have in terms of predicting the future impacts of climate change, so it’s crucial that they are as accurate and as thorough as we can make them,” said the paper’s lead author Peer Nowack, a PhD student in the Centre for Atmospheric Science, part of Cambridge’s Department of Chemistry.
The new research has highlighted a key role that ozone, a major component of the stratosphere, plays in how climate change occurs, and the possible implications for predictions of global warming. Changes in ozone are often either not included, or are included a very simplified manner, in current climate models. This is due to the complexity and the sheer computational power it takes to calculate these changes, an important deficiency in some studies.
In addition to its role in protecting the Earth from the Sun’s harmful ultraviolet rays, ozone is also a greenhouse gas. The ozone layer is part of a vast chemical network, and changes in environmental conditions, such as changes in temperature or the atmospheric circulation, result in changes in ozone abundance. This process is known as an atmospheric chemical feedback.
Using a comprehensive atmosphere-ocean chemistry-climate model, the Cambridge team, working with researchers from the University of East Anglia, the National Centre for Atmospheric Science, the Met Office and the University of Reading, compared ozone at pre-industrial levels with how it evolves in response to a quadrupling of CO2 in the atmosphere, which is a standard climate change experiment.
What they discovered is a reduction in global surface warming of approximately 20% – equating to 1° Celsius – when compared with most models after 75 years. This difference is due to ozone changes in the lower stratosphere in the tropics, which are mainly caused by changes in the atmospheric circulation under climate change.
“This research has shown that ozone feedback can play a major role in global warming and that it should be included consistently in climate models,” said Nowack. “These models are incredibly complex, just as the Earth is, and there are an almost infinite number of different processes which we could include. Many different processes have to be simplified in order to make them run effectively within the model, but what this research shows is that ozone feedback plays a major role in climate change, and therefore should be included in models in order to make them as accurate as we can make them. However, this particular feedback is especially complex since it depends on many other climate processes that models still simulate differently. Therefore, the best option to represent this feedback consistently might be to calculate ozone changes in every model, in spite of the high computational costs of such a procedure.
“Climate change research is all about having the best data possible. Every climate model currently in use shows that warming is occurring and will continue to occur, but the difference is in how and when they predict warming will happen. Having the best models possible will help make the best climate policy.”
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Computer models play a crucial role in informing climate policy. ..
This is analogous to Caligula appointing his horse as councillor.
Consul, or so Suetonius claimed, possibly falsely. Not that I have anything good to say about Little Boot.
Which Climate – Where ???!
That’s that sorted then. the science is settled again.
“Should be included” indicates ozone is not. That does not speak well for the existing state of alarmism.
‘Many different processes have to be simplified in order to make them run effectively within the model’
and there is the door through which GIGO walks in helped along by those who ‘need ‘ the right results and once again we are reminded how poor the models are that support this self and loudly proclaimed ‘settled science ‘
Its hard to think of another area outside of religion, where the more inaccurate your claims prove to be the more sure your are right anyway
“Its hard to think of another area outside of religion, where the more inaccurate your claims prove to be the more sure your are right anyway”
How ’bout Government? Gruber comes to mind.
The paper’s lead author Peer Nowack, a PhD student in the Centre for Atmospheric Science, part of Cambridge’s Department of Chemistry appears to have severe Climate Model Kool-Aid Addiction (CMKAA).
Gotta lay off that stuff, Peer. It may be tasty now, but it’s going to kill your career eventually.
Major advances should be measurable.
How much has the uncertainty in climate sensitivity come down over the past decades?
Nature Climate Change – The Beano for real Menaces.
See this link for a simple multi layer greenhouse model.
http://acmg.seas.harvard.edu/people/faculty/djj/book/bookchap7.html
Under the standard model, ultraviolet radiation passes through the atmosphere on the way to the earth’s surface, which absorbs the ultira violet raditaion, and reradiates in the infrared. The infrared radiation is blocked by the atmosphere- which causes the greenhouse effect.
Ozone high in the atmosphere absorbs ultraviolet radiation directly from the sun, so it doesn’t get to earth’s surface to reradiate in the infrared. The fraction of ultraviolet radiation absorbed by ozone has no greenhouse multiplier effect, so the more ozone in the upper atmosphere, the smaller the effect of atmospheric greenhouse gases.
This was actually a good laugh with classic jokes like, ” scientists have to make informed choices in order to build models which are fit for purpose” and “the Met Office and the University of Reading, compared ozone at pre-industrial levels with how it evolves in response to a quadrupling of CO2.”
I seemed to have missed the physics behind increasing CO2 increasing O3 levels?
Shouldn’t the mechanics come before the model?
But I know better, they need another control knob since the aerosols don’t pass the smell test.
Computer models? Is it even worth propagating this trash?
I have read biofuels produce more ozone than gasoline, oh my.
“It’s worse than we thought, send more money.”
Is slowly morphing into
“It’s more complicated than we thought, send more money.”
But that is true. So for that reason, perhaps we should?
Understanding the weather is a worthwhile endeavour.
What utter crap! How can any computer models do predict even the sun rising in the East and setting in the West when they are based on such junk science in the first place!? As long as they persist with this back radiation nonsense we will remain in the dark ages.
This.
Because, no matter how the back radiation thing is “based on real physics” and even a “demonstrable thing”, the FACTS are that there is no net increase in temperature as a result. Warming, cooling, stability – NONE of these are increased or decreased or affected in any way by “back radiation”, so the “fact” of back radiation is meaningless.
I suspect butterfly wing-flaps are more important to climate than minor changes in CO2 levels.
As the late, great “Father of Climatology” Reid Bryson so sagely observed, “You can go outside and spit and have the same effect as doubling carbon dioxide”.
But then he was a real climatologist who actually studied nature, not a “climate science” computer modeler with an agenda to promote.
hear, hear…………………
Nonsense,my hat makes the skeptics look bad. Stop it.
hear, hear…
Aha! So it’s really oxygen that’s responsible for climate change and not poor maligned carbon after all. Who’d a thunk it? Clearly we have to reduce these people’s oxygen now.
…weather = chaos = not predictable = confused = climate model scientist = $$$,$$$,$$$,$$$…
Lest we forget, GIGO into in to an abacus is the same as GIGO into a computer or a supercomputer.
Here’s the thing. The climate nerds just need to admit two things. 1). The climate is exceedingly complex and 2). The “science” at least with respect to modeling is in its infancy.
I would suggest a couple of successful hindcasts before I would claim to know anything. I’m sure ozone plays a role I’m sure many things play a role sorting out which does what and how much all interacting etc probably going to need decades or even longer if the politics remains front and center.
The CACA Team prefers “tuning” with a putative human component.
What a disaster for the Team if the control knob turns out to be the sun. Unfortunately only real climatology, not “climate science” can discover what the knobs are, ie collecting data, not constructing pie in the sky, hopelessly inadequate models.
“Computer models play a crucial role in informing climate policy. They are used to assess the effect that carbon emissions have had on the Earth’s climate to date….” To date? And what ‘effect’ would that be? Cooling? It’s bad enough that they put so much stock in models but to then ignore variances between reality and model projections and claim the opposite is true?
Just a suspicion, but I believe ozone is the key to centennial scale climate change. The more ozone that is produced by the UV spectral content of solar radiation, the warmer it gets.
That along with clouds, the CCNs of which are modulated by solar magnetic flux affecting GCRs.
Let’s benchmark our latest model against the models we already know to be wrong. Because using real observational data would be very difficult and inconvenient.
Sigh.
“compared ozone at pre-industrial levels with how it evolves in response to a quadrupling of CO2 in the atmosphere, which is a standard climate change experiment.”
Help me understand. Changing the parameters of models is an ‘experiment’? Really?
Lost me at the start of the second paragraph with the mords computer model. Computer model equals total BS.
Aren’t they funny – the way they regard computer originated results as factual!! And, as a scientist, you now will gain much scientific kudos (even prizes) if you can invent really clever computer programmes to foretell our climate in years to come. Ought they not withhold any praise (or prize) until the theories are proved to be correct?
Finally – Sneak Peek:
Better Call Saul: No Parking
http://commoncts.blogspot.com/2014/12/finally-sneak-peek-better-call-saul-no.html