Even though the climate is chaotic to some extent, it can be predicted long in advance.

Climate is average weather, and it can vary unpredictably only within the limits set by major influences like the Sun and levels of greenhouse gases in the atmosphere. We might not be able to say whether it will rain at noon in a week's time, but we can be confident that the summers will be hotter than winters for as long as the Earth's axis remains tilted.

The validity of models can be tested against climate history. If they can predict the past (which the best models are pretty good at) they are probably on the right track for predicting the future - and indeed have successfully done so.

Clouded judgement
Climate modellers may occasionally be seduced by the beauty of their constructions and put too much faith in them. Where the critics of the models are both wrong and illogical, however, is in assuming that the models must be biased towards alarmism - that is, greater climate change. It is just as likely that these models err on the side of caution.

Most modellers accept that despite constant improvements over more than half a century, there are problems. They acknowledge, for instance, that one of the largest uncertainties in their models is how clouds will respond to climate change. Their predictions, which they prefer to call scenarios, usually come with generous error bars. In an effort to be more rigorous, the most recent report of the IPCC has quantified degrees of doubt, defining terms like "likely" and "very likely" in terms of percentage probability.

Indeed, one recent study suggests that the feedbacks in climate systems means climate models will never be able to tell us exactly how much warming to expect. However, there is no doubt that there will be warming.

Given the complexity of our climate system, most scientists agree that models are the best way of making sense of that complexity. For all their failings, models are the best guide to the future that we have.

Finally, the claim is sometimes made that if computer models were any good, people would be using them to predict the stock market. Well, they are!

A lot of trading in the financial markets is already carried out by computers. Many base their decisions on fairly simple algorithms designed to exploit tiny profit margins, but others rely on more sophisticated long-term models.

Major financial institutions are investing huge amounts in automated trading systems, the proportion of trading carried out by computers is growing rapidly and a few individuals have made a fortune from them. The smart money is being bet on computer models.

Of course, in some ways financial markets are much trickier to model than the climate, depending as they do on human behaviour. What's more, trading based on computer models alters the nature of the very thing you're trying to predict.

http://www.newscientist.com/article/dn11649-climate-myths-we-cant-trust-computer-models.html

Ummmm...computer models are biased by the people who program them.

In the matter of climate models....there is absolutely NO WAY that the programmer can install every single variable that could occur in the natural world.

Given the complexity of our climate system, most scientists agree that models are the best way of making sense of that complexity. For all their failings, models are the best guide to the future that we have.

this is EXACTLY why models aren't reliable. The system is SO complex, that even the most complex model cannot take into account all of the variables.

Models are only as reliable as the data entered. Garbage in, garbage out...

And being that the weather guys can't even predict rainfall accurately, I'm not trusting anything that involves the sketchy figures that these models usem. I mean, monday they were predicting a 70% chance oif rain on thursday, but it didn't come until friday. If they can't be accurate on that short a timeframe, how can they predict it 100 years down the road?

Put down the kool-aid.

Exactly.

How many times have the weathermen called for a storm that never materialized??

Read it again,

Climate is average weather, and it can vary unpredictably only within the limits set by major influences like the Sun and levels of greenhouse gases in the atmosphere. We might not be able to say whether it will rain at noon in a week's time, but we can be confident that the summers will be hotter than winters for as long as the Earth's axis remains tilted.

The validity of models can be tested against climate history. If they can predict the past (which the best models are pretty good at) they are probably on the right track for predicting the future - and indeed have successfully done so.

Clouded judgement
Climate modellers may occasionally be seduced by the beauty of their constructions and put too much faith in them. Where the critics of the models are both wrong and illogical, however, is in assuming that the models must be biased towards alarmism - that is, greater climate change. It is just as likely that these models err on the side of caution.

Most modellers accept that despite constant improvements over more than half a century, there are problems. They acknowledge, for instance, that one of the largest uncertainties in their models is how clouds will respond to climate change. Their predictions, which they prefer to call scenarios, usually come with generous error bars. In an effort to be more rigorous, the most recent report of the IPCC has quantified degrees of doubt, defining terms like "likely" and "very likely" in terms of percentage probability.

Dude. It doesn't MERIT being read again.

They cannot accurately predict future climate, especially along the time lines of what they have been attempting, with computer models.

The plain and simple truth, no matter how much they want people to rely on them, is that computer models are only as good as the programmer. There isn't a programmer alive anywhere who could add in ALL of the variables involved with predicting weather.

The validity of models can be tested against climate history. If they can predict the past (which the best models are pretty good at) they are probably on the right track for predicting the future - and indeed have successfully done so.

WHICH climate history, Fanta??

The " history " that came from the rings of a few trees in Siberia??? Which, by the way, don't actually match the trees surrounding them.

If THAT climate history is input into the models, then it's possible for the model to come up with the results they have been touting for a couple of decades.

It will be up to the programmer as to which data is going to be input for the model to be based on.

Programmers are human. They have biases just like every other human. If the programmer believes in Global Warming being caused by man then data to support that will be input. Even if it's not completely intentional, it WILL happen.

There are over 28,000 sets of data.
Take your pick!

..and not ONE of them is a complete dataset.

NONE of them take into account every variable.

Sure they are.
Well they're up to date. I guess they'll never really be complete until Human existence is wiped out.

The data you were talking about,

http://mingle2.com/topic/show/259335

I don't care where the 28,000+ sets of data can be found.

As I have said before, and will continue to say, they are not complete because they cannot possibly take into account every variable.

One of the MAJOR components that almost all of the " reliable " data sets does NOT take into account is the Sun. They all are based on Earthbound predictions only.

That, in and of itself, makes them unreliable.

By the way, have you not seen or heard that it's not only the Earth that is heating up a bit. It's ALL of the planets in the Solar System.

Gotcha, look for the myth to be busted.

Go ahead and try.

Facts are facts and those planets are, indeed, warming.

Whether you like it or not, there is a direct link between the Sun and the planets.

hey...look at the facts here and try REALLY hard to be unbiased.

The sunspot activity has been the lowest in recorded history...and the Earth has cooled down some this year as a result.

Still think there is no correlation???

Keep drinking that Kool Aid, bro.

You insinuate that 'fanta' is drinking 'cool-aid', while it is you dear sir, that is feeding this thread with PERSONNAL and KOOL-AID TASTING dogma.

I thought you might be interested in educating yourself with facts from the field:

'... According to a NASA Goddard Institute for Space Studies (GISS) press release,

"...the solar increases do not have the ability to cause large global temperature increases...greenhouse gases are indeed playing the dominant role..."

The effects of global warming are apparent (see section below) despite the fact that the Sun is once again less bright during the present solar minimum. Since the last solar minimum of 1996, the Sun's brightness has decreased by 0.02% at visible wavelengths, and 6% at extreme UV wavelengths, representing a 12-year low in solar irradiance, according to this NASA news article (April 1, 2009)...'
(http://solar-center.stanford.edu/sun-on-earth/glob-warm.html)

Feel free to counter address these facts, but be clear that personal/kool-aid sourced arguments have no credibility in this climate change discussion.

While subjectivity plays a role in all human exchanges, and leads the way in many trivial topics, objectivity on the other hand, leads every exchange where verifiable measures, comparable sets of findings, and validation within EXPERT PEER groups are the premise.

Personal opinions, preferences, beliefs and dogma are of no relevance in this debate. Let's compare counter scientific data from experts you might have, and let's put it all in perspective.

I agree - models are only as good as the data collected, as well as the base assumptions on the functions of the data... modeling is just that MODELING - it's a forward looking prediction - noone can predict the future, only the likelyhood of the future outcome.

Computer models are an important tool in predicting weather, outcomes of medical treatment, car crash severity and injuries, spaceflight and engineering performance. Computer models have propelled engineering / prediction / manufacturing to a level of amazing accuracy and useability -- case in point - computrer modelling was used to land a craft on mars long before we actually accomplished it -- successfully as I might add.

Humans want computers to be perfect and tell us what the future will be... REALLY? yeah, not so much.... I would not want to live in a world where we did not utilize computer modeling, it helps society too much to be discounted...

Is it perfect, of course not - things rarely are...

P.S. when the weatherman says "70% rain on thursday", he's not saying "there is a 70% chance of rain on thursday" == what he is saying is "70% of the time when the conditions are similar - it rains"....

Interpretation of the result is as important as the model itself.

$.02

Insofar as global warming - there is a direct correlation between the temperature of the sun, and the temperature of the earth...

Uhm... DUH! *sheessh*

http://www.petitionproject.org/review_article.php

models are imperfect because they rely on assumptions. the whole model is itself an assumption. "if CO2 doubles what is the affect?"

on the other hand the latest models I saw showed West Texas as becoming semi-tropical with lakes and rivers. That would be an improvement so, so far I'm all for the global warming thing

Scientific models are imperfect as all things human are.

The inescapable point here is that scientific models and the intrinsic validation process to which they are subjected, are FAR LESS IMPERFECT than gross generalizations, special interest based personal opinions, as well as one-track faith, political or business motivated crusades.

Scientific modeling rests on a time honored iteration process, thus a PERFECTIBLE foundation.
The other groups, rest on an inexistent factual base, therefore absolutely unverifiable and much less PERFECTIBLE.

A scientific argument must be challenged by its correlate counter scientific argument. Personal opinions, beliefs, etc., will never relevant nor pertinent.

At this point in the climate change scientific debate, the counter climate change scientific data and findings (nature and volume) are failing to make a dent in the overwhelming consensual data and findings for human caused climate change. (human is not the only factor, but it scientifically IS A FACTOR)

scientifically? really? Maybe read this first...

http://petitionproject.org/gw_article/GWReview_OISM150.pdf

the rise in temperature began BEFORE the expansion of world hydrocarbon use... (go figure)... of course, feel free to hang your hat on Al Gore...

$.02

Can I ask just one question:

-What temperature the globe should be set?


Anyone answers the perfect question should get a Nobel. If you can't answer it, don't debate about climate or climate change.

Here is the consequences of making up stuff on unreliable data and "ballpark" figures.



http://www.timesonline.co.uk/tol/news/environment/copenhagen/article6956783.ece


The world is not made of zeros and ones.

We live in, in a fractal world, where those little numbers after the 0.??????? will add up and "rounding up or down" is pretty much ignorance, let alone making up "ballpark" figures.

I liked that other thread that showed the current models being used are incomplete and using flawed assumptions to forecast. the recorded data is not jiving with the predicted values and the guy (forgot his name) used recorded data to revise the models

the one that showed how the semi transparent atmosphere is self regulating to provide the most optimum radiometric transfer by adjusting its optical dessity through negative feedback

but I can't find it now