In order for global warming theories to be scientific they must be falsifiable. The theories must be able to actually predict future climate. If they can't do that then they are worthless.

The IPCC started trying to predict future climate changes almost 20 years ago. We have their estimates of climate change from 1990, which were calculated using computer models. This means we have 18 years of historical data that we can compare with the predictions from the models made before the data was known.

How did the models do? In a word, horrible. You would literally do much better by just intuitively extending the trends developed over the previous 10 or 20 years into the future. (And yet the models were all pretty much in agreement with each other. So much for the value of a consensus!)

The conclusion of the investigators looking into this was remarkable for its restraint: "This makes future climate predictions not credible."

In other words, basing policies on the predictions of these climate models is bad science. And no, the basic features of the models have not changed much in the last 18 years, certainly not enough to justify setting aside skepticism.

http://www.itia.ntua.gr/en/docinfo/850

Every genuine test of a theory is an attempt to falsify it, or to refute it.
Karl Popper


If you happen to get out of the Ivory Tower from time to time, you might want to visit a Glacier before they’re all gone.

http://www.swisseduc.ch/glaciers/morteratsch/comparison_2007...

HERETIC!!!!!! Burn him at the stake!!! We don't need no stinin' data!!!!!

If you happen to get out of the Ivory Tower from time to time, you might want to visit a Glacier before they’re all gone.

Nobody that I know of says that the Earth is not in a warming trend. It is part of the natural cycle of the planet. The problem comes in predicting the rate of change.

There are also those folks with PhD after their names that feel the cycle is going to grow colder before too long. I don't have the expertise to sort out which set of facts are better. All I can do is compare the success of yesterday's model verus reality. The results do not give confidence that the alarmists are correct.

How did the models do? In a word, horrible.

You know little worth knowing. You are totally wrong. Please come up for air. See

"Coupled models are becoming increasingly reliable tools for understanding climate and climate change, and the best models are now capable of simulating present-day climate with accuracy approaching conventional atmospheric observations," said Reichler. "We can now place a much higher level of confidence in model-based projections of climate change than in the past."
The many hours of studying models and comparing them with actual climate changes fulfills the increasing wish to know how much one can trust climate models and their predictions. Given the significance of climate change research in public policy, the study's results also provide important response to critics of global warming. Earlier this year, working group one of the IPCC released its fourth global warming report. The University of Utah study results directly relate to this highly publicized report by showing that the models used for the IPCC paper have reached an unprecedented level of realism.

http://www.sciencedaily.com/releases/2008/04/080402100001.ht...

Interesting you bring this up MyCynic. I was just reading TechTalk a newspaper from MIT with recent highlights of what goes on there.
Edward Lorenz just died at 90. He was the discoverer of the "butterfly effect" and the originator of Chaos theory, which showed that weather cannot be predicted for more than a few weeks at best. Lorenz realized in his studies of meteorology that small differences in a complicated dynamic system such as the atmosphere could trigger vast and often unexpected results.
I think the adherents of the problem of global warming are not so much sure that a disaster will happen, but they are afraid they will not be able to predict what disaster will happen and how to deal with it, because, well, according to Chaos theory, it will be unexpected. Moreover it could be vast.
It makes no sense to argue politics when it involves natural disasters. As many have pointed out to you before, and you apparently do not listen, If something bad happens, politics will be pointless.

MrCynic wrote:

"You would literally do much better by just intuitively extending the trends developed over the previous 10 or 20 years into the future."


And what happens if you do that?

wolverine wrote:

"There are also those folks with PhD after their names that feel the cycle is going to grow colder before too long. I don't have the expertise to sort out which set of facts are better. All I can do is compare the success of yesterday's model verus reality. The results do not give confidence that the alarmists are correct."



What irritates me about this discussion is that even if most of the global warming claims are bogus, we have plenty of other reasons to bail from using so many fossil fuels. I've been saying that for a number of years now and the geopolitical problems that come from our reliance on these energy sources only continue to get worse.

Wouldn't it be nifty to just tell the middle east to go stuff it, we don't need their oil, and if they want to blow each other to smithereens we'll respond with just as much nothing as we do when the Sudanese do it?

The University of Utah study results directly relate to this highly publicized report by showing that the models used for the IPCC paper have reached an unprecedented level of realism.


That's technically not inconsistent with what MrCynic says. The models can be much better than they were before, and still be awful. I work in a very different field but one where a similar trend holds: are models are getting better but they are still very bad on the whole.

The article doesn't provide any details. It would be interesting if someone has the time to actually dig up the U Utah study and read exactly what it says. I'm not sure I can get access to it though.

Actually, what was predicted by the IPCC has been conservatively wrong, that is, the predictions given so far have been worse than "worst case" scenarios so far:

http://en.wikipedia.org/wiki/Intergovernmental_Panel_on_Clim...


Some critics have contended that the IPCC reports tend to underestimate dangers, understate risks, and report only the "lowest common denominator" findings.[53]
On February 1, 2007, the eve of the publication of IPCC's major report on climate, a study was published suggesting that temperatures and sea levels have been rising at or above the maximum rates proposed during the last IPCC report in 2001.[54] The study compared IPCC 2001 projections on temperature and sea level change with observations. Over the six years studied, the actual temperature rise was near the top end of the range given by IPCC's 2001 projection and the actual rise was above the top of the range of the IPCC projection.
An example of scientific research which has indicated that previous estimates by the IPCC, far from overstating dangers and risks, has actually understated them (this may be due, in part, to the expanding human understanding of climate, as well as to the conservative bias, noted above, which is built into the IPCC system,) is a study on projected rises in sea levels. When the researchers' analysis was "applied to the possible scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC), the researchers found that in 2100 sea levels would be 0.5–1.4 m above 1990 levels. These values are much greater than the 9–88 cm as projected by the IPCC itself in its Third Assessment Report, published in 2001.[55][56]

While they may not have the modeling right, the conclusions based on other information (studies, historical data, physical evidence) are still showing the climate is changing due to man at a noticeable rate.



Duck

The theories must be able to actually predict future climate. If they can't do that then they are worthless.

What degree of accuaracy are you demanding?