- Thread starter
- #161
You are a liar. That's not an 'insult', that's a fact. Here's the proof. And BTW, you are very obviously not "reading all the data", you lying smarmy halfwit (now, that's an insult and one you richly deserve).
Climate Models: How Good Are They?
By Lisa Moore - scientist in the Climate and Air Program| Bio
Published: July 18, 2007
(excerpts)
...Which brings me to how we know the models are credible. What if the model inputs were actual observations from a time period in the past where we have full climate measurements? If the model is any good, it should accurately "hindcast" what we know the climate conditions were. In fact, hindcasting is the technique scientists use to evaluate models. If a model can accurately hindcast, we can have some confidence in its forecasts of the future. In the graph below, the yellow lines show 58 temperature hindcasts from 14 different climate models. The thick red line is the average of all the hindcasts; the black line shows actual global temperature over the past century. Note how close the hindcast average is to actual temperatures. The models do a very good job of predicting 20th century climate.
Are the Models Untestable?
(excerpts)
Some global warming deniers assert that the global climate models (GCMs) used to analyze and predict climate change can be ignored because they are "untestable" or "have no predictive ability." Are the models, in fact, untestable? Are they unable to make valid predictions? Let's review the record. Global Climate Models have successfully predicted:
* That the globe would warm, and about how fast, and about how much.
* That the troposphere would warm and the stratosphere would cool.
* That nighttime temperatures would increase more than daytime temperatures.
* That winter temperatures would increase more than summer temperatures.
* Polar amplification (greater temperature increase as you move toward the poles).
* That the Arctic would warm faster than the Antarctic.
* The magnitude (0.3 K) and duration (two years) of the cooling from the Mt. Pinatubo eruption.
* They made a retrodiction for Last Glacial Maximum sea surface temperatures which was inconsistent with the paleo evidence, and better paleo evidence showed the models were right.
* They predicted a trend significantly different and differently signed from UAH satellite temperatures, and then a bug was found in the satellite data.
* The amount of water vapor feedback due to ENSO.
* The response of southern ocean winds to the ozone hole.
* The expansion of the Hadley cells.
* The poleward movement of storm tracks.
* The rising of the tropopause and the effective radiating altitude.
* The clear sky super greenhouse effect from increased water vapor in the tropics.
* The near constancy of relative humidity on global average.
* That coastal upwelling of ocean water would increase.
Seventeen correct predictions? Looks like a pretty good track record to me.
References for Predictions and Confirming Observations - (see site)
Oh yes, how good are they? Turns out they are significantly WORSE than RANDOM GUESSING! Yeppers, your models are so good a psychic can do much better than your precious models.
What a joke....
"A 2011 study in the Journal of Forecasting took the same data set and compared model predictions against a random walk alternative, consisting simply of using the last periods value in each location as the forecast for the next periods value in that location. The test measures the sum of errors relative to the random walk. A perfect model gets a score of zero, meaning it made no errors. A model that does no better than a random walk gets a score of 1. A model receiving a score above 1 did worse than uninformed guesses. Simple statistical forecast models that have no climatology or physics in them typically got scores between 0.8 and 1, indicating slight improvements on the random walk, though in some cases their scores went as high as 1.8."
Junk Science Week: Climate models fail reality test
