How can you predict global warming if you can’t predict rain?
Some say climate change is part of a complex natural cycle – so complex, in fact, that it can’t be forecast. Are current climate models reliable?
By Peter N. Spotts Staff writer of The Christian Science Monitor
To those of us who are not climate scientists, it may come down to this: How can we be so certain what the climate will be like a century from now if you can’t get a decent weather forecast more than two weeks ahead? In the end, isn’t climate change just too complex?
True, weather forecasters are fallible, and there is no planet out there similar to Earth so we can truly gauge the effect human activity is having on our climate. But climate researchers are increasingly confident of their models and simulations. Besides, some argue, predicting the weather is tougher than predicting the climate, and scientists have been working on perfecting climate models for more than a century.
In a chilled, windowless room here at the National Oceanic and Atmospheric Administration’s Geo physical Fluid Dy namics Laboratory (GFDL), a supercomputer is furiously crunching numbers in an attempt to mimic Earth’s climate system.
It’s a tool Svante Arrhenius could only dream about. In 1896, the mustachioed Swede gave the first detailed description of carbon dioxide’s warming effect on climate. He had to solve some 10,000 equations to do it. Armed with his crude climate model, he reckoned that if the amount of CO2 in the atmosphere doubled, global average temperatures might rise by up to 9 degrees F. Today’s modelers say his estimate is high – but not by much.
Today’s climate models try to simulate more than one feature – more than Arrhenius’s CO2 – of the climate system and in greater detail. They’re still far from perfect and miss important processes.
Read the full article here.
Hat tip to Marc Morano.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
“Armed with his crude climate model, he reckoned that if the amount of CO2 in the atmosphere doubled, global average temperatures might rise by up to 9 degrees F. Today’s modelers say his estimate is high – but not by much”
Simplicity remains the key.
All in all a good article
Yes Gavin a good article where the journo made the effort to produce an objective piece.
Simplicity is good, but the climate system is complex.
Paul, life is complex. Understanding every detail is not essential in the process of living. The will to be something should dominate our philosophy regardless of education, science etc.
The old adage practice makes perfect stands in regards to our models.
Let’s get one fact established – Arrhennius did not measure this property of CO2 affecting the atmosphere’s temperature, he deduced from solving 10,000 equations as described in the text.
He assumed that increasing CO2 would cause some heating and rather than conducting a physical experiment to verify that, he instead went for mathematical modelling.
This is essentially the Socratic or Deductive mode of reasoning and it suffers from one fundamental flaw.
What IF the initial assumption is wrong?
Science does not work like this.
There you go again Louis, introducing logic and common sense will do no good in AGW debate.
Cheers
Hey Louis, who else is “conducting a physical experiment to verify that” it’s not so?
Louis – “What IF the initial assumption is wrong?”
Then it would have been picked up the hundred or so following years of study. What, do you think that in this time no-one thought to question the initial assumption?
Science does not work like that.
I have posted this before but before anyone goes off on the 10 000 equation thing PLEASE read this concise history of AGW from Spencer.
http://www.aip.org/history/climate/co2.htm
The Economist also has a good article on this at http://www.economist.com/science/displaystory.cfm?story_id=9645336.
There’s also an article linked from this one, near top of right column, called “Modelling the Climate”. Don’t be too impressed with models though. Reasonably accurate output does not mean reasonably accurate processing. Models are loaded with assumptions. Elements might have a counterbalancing impact on each other, the model might assume an effect that does not exist or the model might be incorrectly based.
By the latter I am saying that if something changed almost immediately as a consequence of a temperature increase but there was evidence that it might make a tiny contribution, modellers might look at the correlation and assume that it was a major driver of temperature instead of a consequence.
Correlations are a ruse argument – you need mechanistic understanding, modelling and ability to represent observational data with understanding. Which has all been discussed ad nauseum here for years.
“might” just indicates made-up excuses.
Ender,
I think you better get an understanding of the salient differences between the deductive method and the empirical method.
The deductive method starts with an agreed assumption and on common agreement deems it by consensus to be true, here climate sensitivity. Hence no one bothers testing it since it is supposed to be true.
Now go back and think about it.
Gavin,
As far as I know no one is doing the experiment. To do so requires funding by getting a research grant and no one in the AGW industry will be interested in funding an experiment that may prove them wrong.
There is also a small practical problem in doing such an experiment, another reason why no one seems be interested in doing it.
Climate sensitivity is really nothing but a belief that doubling CO2 in an atmosphere will cause it to rise in temperature. Except that Mars with 95% CO2 is -85F and if you ad Venus with its temperature together with the earth, you get a graph of CO2 vs Temperature that is anything but a linear fit. There is no correlation between T and CO2 and on that basis alone one would reject teh idea of climate sensitivity.
Dick Lindzten did say in the Swindle Documentary that calculating it from first principles is easy and the sensitivity is about 1 kelvin.
Since the base line was 280 ppmv CO2, we are now at almost 75% of a CO2 douobling and the temperature has only rises 0.6 Kelvin.
However this assumes that all other variables are held constant and only CO2 is allowed to vary. And we ignore totally the mass of the earth as a source of heat energy to its atmosphere.
It’s very easy being sceptical of AGW – It’s a Holey Theory.
Utter tripe.
Louis, are you suggesting we are at or near 490ppm CO2?
Louis – “The deductive method starts with an agreed assumption and on common agreement deems it by consensus to be true”
Here are the definitions of the deductive and empirical methods.
“Empirical method is generally taken to mean the collection of data on which to base a theory or derive a conclusion in science.”
“The hypothetico-deductive model,[1] [2] or method is a proposed description of scientific method. It was popularized by Karl Popper.[3] According to it, scientific inquiry proceeds by formulating a hypothesis in a form that could conceivably be falsified by a test on observable data. A test that could and does run contrary to predictions of the hypothesis is taken as a falsification of the hypothesis. A test that could but does not run contrary to the hypothesis corroborates the theory. It is then proposed to compare the explanatory value of competing hypotheses by testing how stringently they are corroborated by their predictions.”
Neither of them involve an agreed assumption. The deductive method proposes a theory that is then tested not assumed to be true.
Perhaps you should think about it.
Louis – “Climate sensitivity is really nothing but a belief that doubling CO2 in an atmosphere will cause it to rise in temperature. Except that Mars with 95% CO2 is -85F and if you ad Venus with its temperature together with the earth, you get a graph of CO2 vs Temperature that is anything but a linear fit.”
So you the wise logical scientist would take 3 utterly different planets in different orbits with different rotation rates, different amounts of oceans, different surface gravities etc and then use this to derive a climate sensitivity for Earth. I agree with Luke – Utter tripe and it is Louis back to his incoherent best.
Right back to when you said that deserts drop in temperature because heat is not being trapped and I said do you freeze solid as the temp plunges to -30° what do you think causes the greenhouse effect that warms the Earth?
Louis
“As far as I know no one is doing the experiment. To do so requires funding by getting a research grant and no one in the AGW industry will be interested in funding an experiment that may prove them wrong.”
Interesting and a major scandal. Could you just let me know what evidence you have of this fact?
Guys I once was gonna study mathematics at a higher level, in high level for those times Statistical and econometric modelling. As everyone knows the precursor back then was project work, so I took a one semester project work under a great mind.
Now this fella would not tell me what we were computer modelling it was hush hush, he just gave me the variables and the programming, back then a lot of mathematicans couldn’t model on computers, unfortunately he was one of them and the math department wasn’t crawling with computer literacy, fortran (some dumb aussie cold war thing I dont know).
A whole new scientific branch had just made bachelorhood, computer science. Anyway I got a pass conceded lost two honors in other subjects for having a fight with the great mind, licked his boots and moved on.
My point by way of observation when people have the audacity to hide premises and limit premises, science and humanity can get hurt.
This environment thing is our galaxy at the top and the atom at the bottom this wis hat we are are having a fight over. The source must be open. The minds must have all of the data and the intent of the research must be a truth that stands.
May Gaia and her acolytes defend you always.
Science is finding the hidden not hindering the truth.
SJT,
Who is trying to do the experiment? Are you at all familiar with the university grant systems to get any funding for an experiment that contradicts the ruling paradigm?
There is plenty of published comment about the fact of the non-receipt of funding for contradictory experiments or publishing of papers.
The astronomer Halton Arp demonstrated that redshift had nothing to with distance from the observation and for his insights he was effectively banned by mainstream astronomy and refused permission to use the telescopes etc. Again this scandal has been well documented.
Similar issues exist in getting scientific papers about plasma cosmology in the mainstream astronomical journals, and other areas in which this exists is in my own area of science, geology.
It’s all out there SJT in the internet – an awful lot of hard evidence for this.
Specifically climate sensitivity?
I was wondering when someone was going to ask me that.
Like astronomy SJT, and historical geology, we cannot do laboratory experiments for obvious reasons. It is an enormous problem and such areas of science tend to favour the deductive method of reasoning, instead of the empirical. (Exploration geology, on the other hand, is totally empirical – every next drill hole can falsify the hypothesis – and this cannot be done when we are dealing with the far, far away and the long, long time ago issues.
Nor can we model the earth’s surface state in a computer or laboratory set up.
If the hypothesis cannot be falsified, then it is a scientific one. Climate sensitivity is in this category.
Correct, if it cannot be falsified, then it is not a scientific one.
Apologies.
Louis
I didn’t ask for your opinion, I asked for evidence.
Louis
AGW predicted that the stratosphere would cool, and the troposphere warm. That is what has happened.
Al ole mate, I have to say it here too, this preoccupation with ‘science’ is an aberration for mankind.
Stuffing up the garden that feeds us is what we do best.
Sorry for late comments, I have been in travel mode driving, to and from, Halls Creek to Kununurra, from which I travelled on a Jet plane to and from Perth.
Now SJT, looking at your first comment – evidence? Measured anthropogenic CO2 has accelerated, but the global measured temperature seems to have cooled.
So refute this fact first please.