Do you believe 'climate models' are the most useful tools for gauging future changes on our planet?

Question

These computer-based mathematical models simulate, in three dimensions, the climate's behavior, its components and their interactions.

http://www.climate.noaa.gov/index.jsp?pg=./cp_cf/description.html

http://www.metoffice.gov.uk/research/hadleycentre/models/modeltypes.html

Answer 1

Once again JELLO assigns more to the question than was asked - because he/she is politically driven.  

Jen L wasn't asking if Climate Models were accurate "predictions of the future" - she was asking if they were "useful tools for gauging future changes."

That's much different than "predicting".  Once again, JELLO adds to the obsufication of science - the very core understanding is clouded.  A prediction implies absolute certainty.

The key words are "useful tools".  Yes - climate models are fed a ton of data from many sectors - not just meteorology.  These tools help us make our most educated "guesses" - so we can develop an hypothesis on what we think might happen based on what has occured historically and based on our understanding of core scientific principles.  

When an apple falls from the tree (on Earth) we pretty much assume that it's going to fall DOWN.  

However, there will always be a degree of uncertainty - even with this principle - and it's this degree of uncertainty that folks like JELLO like to glom onto as "proof" that scientists are "wrong" when it comes to climate change (or evolution, or relativity).

The whole point of crafting these models (and science in general) is to bring us closer to reducing as much as possible that degree of uncertainty.  

And true scientists (i.e. skeptics -proper) understand that the degree of uncertainty never goes completely away - we simply make every attempt to make it:

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YES.  Models are the best tools available right now to work towards increasing our understanding.

Answer 2

Ummm...what ELSE would you use?

In spite of "Dr. Jello" answering in the negative, and his sneering at the models, any models developed which can track long periods of climate change with past data have to have some amount of validity; his statement about them not predicting the climate accurately has yet to be tested, really.

If he's talking about predicting "the weather"--which is very local and has all sorts of high variability--then you can see for yourself how accurate different computer models used by your local news guys really _is_...which is sometimes yes and sometimes no.

But computer models for CLIMATE are not the same and are looking for how the averages (temp, etc.) as a whole move and change.

Answer 3

These models can be manipulated to give any result desired.  They are based on reconstructed, selected data and are only good for predicting the past.

Answer 4

No, not yet. Computing power is only capable of handling General Circulation Models or GCM, which do not accurately model cloud cover. In order to accurately model climate, low cloud cover must be simulated and it's impact on Earths radiation budget would require a computer system 1000 times more powerful than what is currently available. The last 100 years of climate change could be caused by natural variation and the most advanced climate simulation would never know the difference.

http://www.rdmag.com/ShowPR.aspx?PUBCODE...

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Answer 5

Scientists have been using models for a very long time.  Some are physical models, some pure math (without computers), and many are now computer based.  Since no scientists or observer can travel into the future and report back to us, models are the only tool science has to make future projections.

A good model (physical, math, or computer) will be able to demonstrate the ability to match previously observed events (e.g. declining population of some species or cloud cover over a region). Once that has been demonstrated, then there is a level of confidence for letting the model perform beyond the observed events to project future events/conditions.  Over time, those models projections can be compared with observed events that occurred after the projections, adding even more confidence to the validity of the model.

There currently is a growing level of confidence among climate scientists for models ability to project temperature. Here's some good links for educating yourself on climate modeling:

http://www.metoffice.gov.uk/research/had...

http://mapenvironment.org/wiki/index.php...

http://www.ccsm.ucar.edu/

http://aip.org/history/climate/GCM.htm

Answer 6

Digital modeling is relatively new. However, humans have been using analog modeling since the dawn of time; the sundial, Stonehenge, mechanical clocks, the abacus, mechanical calculators and the Antikythera mechanism are examples.  

And so we can and have had the ability to predict the future for thousands of years.

Early computer models of the climate were able to show the direction of the change and some hints at the magnitude, and supported earlier theoretical predictions. Later models confirmed the trend and narrowed the range of uncertainty. Surely models are imperfect and are constantly improving, but this is not the point.

As different investigators approach the problem with different computational methods, the different models all show the same trends and general outcomes. As greenhouse gasses increase, average temperature increases. Warming will be greater at the poles and at night. As atmospheric moisture increases due to the ability of warmer air to hold more moisture, precipitation events will become more intense. These effects are occurring now exactly as the models predicted.

Digital modeling is not some sort of alchemy. Theoretical science is based on mathematics. Mathematics is internally consistent and irrefutable. A theoretician uses mathematics to prove that his theory is internally consistent. The theory may have no practical application at this point, but it is a valid framework for further study and application. Newton remains a giant because the calculus he invented has endless applications.

Empirical scientists design experiments to test the theory. After the theory and the mathematics have been proven to be correct by direct measurement through experimentation, the same mathematics from the theory is used to design the model.

Models are used to design nuclear weapons, chart spaceflight, model astrophysical phenomena like star and galaxy lifecycles, model particle interactions in nuclear physics, model biochemical reactions for the design and efficacy of drugs, model population growth, model economic systems, model thermodynamic systems for combustion and engine design, model material behavior for structural design, and more I haven’t thought of.

The point being that the models aren’t “twisted, fudged, and manipulated in order to get the results desired”. They are used every day around the world by scientists and engineers to make things that work.

Computer modeling has opened a new chapter in science. Empirical scientists were once limited by that which they could construct and observe. Now we can take models, which are proven to be internally consistent because they arrive at the same results obtained from direct measurement, and drive them beyond the directly obtainable. We can drive them into the future, into the past, speed them up, slow them down, enter parameters that would be unrealistic or uneconomic or impossible for a researcher with practical constraints. Sometimes the models produce nonsense. Sometimes they produce results that the researchers are unable to explain, and thus open a new field of inquiry. It is a new frontier.

It amuses me that people use weather models as proof they are no good. “We can’t predict the weather next week, who is to say what will happen in 100 years?” The point is we can predict the weather next week with some accuracy. We can predict the weather tomorrow within a degree or two of temperature and an hour or two of when the precipitation will arrive. That is an incredible achievement.

Answer 7

they are a very powerful tool. as we get more accurate data and better understanding of complex earth systems such as marine currents and weather cycles, they get ever more useful.

Answer 8

They are useful tools but are also easily manipulated to produce a desired result. In addition, the assumptions are often so much greater than the known facts.  The systems are so complex that they take computing power that is pretty difficult to achieve and even then are lacking.  By obtaining greater understanding and increasing computer processing speeds, the tools should become more useful.

Answer 9

global warming is a myth

Answer 10

Absolutely.  It's funny that the 'skeptic' argument is that models *can* be used to predict whatever the modeller wants.  This is somewhat true (but not really, because the modeller is constrained by physical principles and by the data), but does it mean that modellers *will* manipulate models to meet their desired projections?  Of course not.  Scientists want to be accurate.  The 'skeptic' argument is that scientists are purposefully dishonest in order to be 'alarmists'.  As usual, the 'skeptics' are relying on conspiracy theories and ignoring the scientific reality of the situation.

In reality, climate models have both accurately hindcast the climate changes of the past century:

http://www.globalwarmingart.com/wiki/Ima...

And accurately predicted the warming which occurred over the past 20 years:

http://www.realclimate.org/index.php/arc...

These models are critical in determining the rate of future warming and its effects on the global climate, and they have proven to be extremely accurate.

Answer 11

No, but they're great for letting the researcher get the results that they want to get.

Answer 12

If all the data is accurate, yes. However gaging future events will be difficult, because we cannot predict random events that could change the outcome.

Answer 13

Beelnite said:

"YES. Models are the best tools available right now to work towards increasing our understanding."

This is a nice point, but it isn't really answering Amy L's question.

Are models useful? Well, it depends on what you mean by useful--they are useful for advancing knowledge of our climate. Are they useful for policy decisions through predictions or projections? Likely not, being that the range and error bounds are so large as to accommodate large periods of static global temperatures  and any number of outcomes.

And despite what others have said in this thread, "hindcasting" does not and cannot decide a model's "usefulness" or "accuracy". Models are often (almost always) subject to "tweaking" to help match historic temperatures, and this practice is commonplace in the modeling world--tweak the model to match observed data.

Models are hypotheses that are based upon our limited understanding of the physical world, and as the saying goes: "physical laws never change, only our understanding does".

Dana said:

"These models are critical in determining the rate of future warming and its effects on the global climate, and they have proven to be extremely accurate."

Extremely is a bit over the top.

And Dana, do you have any experience in modeling? Hindcasting isn't a particularly useful measure for deciding a models "accuracy".

Answer 14

No - People who believe in these models will tell you that they can accurately 'hindcast' the climate back over 1000 year, but they fail to predict the climate for any time in the future.  This proved that the data input into the models are twisted, fudged, and manipulated in order to get the results desired.

No one, not even computers can predict the future.

Answer 15

How else are you going to gage future changes, ask the oil and coal companies? Find the climate equivalent of Punxsutawney Phil?

Answer 16

Other than The Farmers Almanac they are pretty much the ONLY tools available. ;-)

It wasn't until about the last 6 years that computers powerful enough to calculate all the parameters were available to run climate models in a timely fashion.

The Hadley Center uses the CIAS supercomputer.  The Canadian Meteorological and Oceanographic Society uses climate modelling computers at the University of Montreal and the University of Victoria, among others.  The NOAA uses the National Center for Environmental Prediction which has connections of multiple sources of data and modelling around the world.

The same is true of most countries, when you have a problem this large eventually the wheels of government turn and the money and resources are provided to the EXPERTS to do their work faster and more accurately.

Industry, of course, has methods to provide money to naysayers faster. What was one of our favorite naysayers favorite answers? "Follow the money!"

Yes, please do!

Answer 17

Absolutely Not!

People tend to believe that computers have the capability to think and predict upcoming events.

A computer can only output what it is told to do, by the program that it is running.

They are useful tools to 'crunch numbers' very rapidly, since they can do millions of calculations per second, but in the end they will only produce whatever it is told by the program that it is running, and the information it is being fed.