1981 Paper's Predictions for Global Temperatures Spot-On 371
Layzej writes "The Register reports on a paper published in Science in 1981 projecting global mean temperatures up to the year 2100. 'When the 1981 paper was written, temperatures in the northern hemispheres were declining, and global mean temperatures were below their 1940 levels. Despite those facts, the paper's authors confidently predicted a rise in temperature due to increasing CO2 emissions.' The prediction turns out to be remarkably accurate — even a bit optimistic. The article concludes that the 1981 paper is 'a nice example of a statement based on theory that could be falsified and up to now has withstood the test.'"
Re:monkeys throwing darts... (Score:4, Informative)
I'm not sure what part of this data is falsifiable
Data is not falsifiable, it is either correct or it isn't: it is scientific theory that's falsifiable.
Re:monkeys throwing darts... (Score:5, Informative)
I'm not commenting on the climate one way or the other
Sure you are. You're argument in a nutshell, goes like this:
1. Premise: There were hundreds of predictions about what would happen to the climate over a 30 year period.
2. Premise: One prediction was demonstrably right.
3. Inference: because 99.9% of the predictions were wrong, the one that was right must be due to pure chance.
4. Final conclusion: I can safely ignore any other prediction about climate from anybody, because the only way it can be right is by pure chance.
Well, that's not how science works. The logic of science works more like this:
1. Premise: There were hundreds of predictions about what would happen to the climate over a 30 year period, each using different models and ideas to arrive at that prediction.
2. Premise: One prediction was demonstrably closer to right than the others.
3. Inference: The models and ideas that produced the correct prediction are closer to the truth than those that didn't correctly predict a result.
4. Final conclusion: When making the next prediction, start from using those models and ideas and you'll get pretty close to the right answer.
Here's a similar problem from physics:
Model A: Acceleration due to Earth's gravity near the ground in a vacuum is ~10 m/s^2, so the ball should fall 100 meters in 4 seconds.
Model B: Acceleration due to Earth's gravity near the ground in a vacuum is ~5 m/s^2, so the ball should fall 100 meters in ~5.8 seconds.
Time for a ball to fall 100 is slightly over 4 seconds. Ergo, 10 m/s^2 is less wrong than 5 m/s^2.
In the words of Isaac Asimov, Model A is wrong, Model B is wrong, but if you think that Model A is as wrong as Model B, then your view is wronger than both of them put together.
Re:monkeys throwing darts... (Score:4, Informative)
Honestly, I think you should have kept that to yourself, because on second thought it doesn't make much sense. Nostradamus' "predictions" are incredibly ambiguous, which is why they can be made fit observations after the fact. Quantities such as degrees Celcius/Fahrenheit are not; the observations either fit within the specified level of precision or not.
Re:monkeys throwing darts... (Score:5, Informative)
I'm sorry, you're clueless.
"Climate" means 30-year average in this context. Being able to predict next year's specific temperatures has nothing to do with climate.
Think of the stock market. "Climate" is the 30-year graph and the ability to say "from 1982 to 2012 the trend is ever increasing". http://www.google.com/finance?chdnp=0&chdd=0&chds=0&chdv=1&chvs=maximized&chdeh=0&chfdeh=0&chdet=1333730258898&chddm=4050760&chls=IntervalBasedLine&q=INDEXDJX:.DJI&ntsp=0 [google.com]
"Weather" is saying "last year was up and down". http://www.google.com/finance?chdnp=0&chdd=0&chds=0&chdv=1&chvs=maximized&chdeh=0&chfdeh=0&chdet=1333730383316&chddm=98923&chls=IntervalBasedLine&q=INDEXDJX:.DJI&ntsp=0 [google.com]
You're confusing "long term trend" with "what will it be like this weekend". They are two distinctly different things.
Re:monkeys throwing darts... (Score:5, Informative)
If you can predict the climate, publish your predictions for each and every weather station so we can compare predicted values to actual values. (Oh, and yes, I do know the difference between weather and climate.) But no, we get some hazy predictions for something in 100 years, yet nothing for next year.
It's funny. You claim that you know the difference between weather and climate, and yet you repeatedly mix up the concepts the rest of the time. If you know the difference, why do you want to be given a prediction for a specific location? If you know the difference, why do you want to be given a prediction for the coming year?
The bizarre thing is that if you look at the graph you can see what they thought it would be next year, and indeed all years to the end of the graph. As it gets further into the future then the error range gets bigger because they can't know what the human response to this problem would be.
Moronic arguments about weather vs. climate are not science.
And moronic arguments that get weather vs climate wrong are also not science. This doesn't change merely because you keep mistakenly claiming that you do know the difference.
Re:What about the rest? (Score:4, Informative)
I would also be interested in knowing about other predictions, in particular predictions with specific numbers backed by plausible theoretical models
Here's one from the same researcher [rankexploits.com], from 7 years later, after spending half a decade of super-computer time simulating the warming.
.3 degrees Celsius.
To understand the graph, the red line (Hansen A) was calculated assuming and annual increase of atmospheric CO2 of 1.5% per year. The orange line (Hansen B) was calculated assuming that the annual increase of atmospheric CO2 would be constant, and the yellow line (Hansen C) was calculated assuming CO2 output would decrease so much after 1990 that by 2000 it would cease to increase. He was optimistic in the scenario.
You can also look at the first IPCC report from 1990 [wikipedia.org] which predicted a rise of
Re:monkeys throwing darts... (Score:5, Informative)
Bullshit. Ptolemaic system made accurate predictions, but based on completely wrong understanding of reality. Credence my ass.
The Ptolemaic system was not discarded because it was wrong. It was discarded because the Newtonian System made more accurate predictions.
Re:monkeys throwing darts... (Score:4, Informative)
The Ptolemaic system was not discarded because it was wrong. It was discarded because the Keplerian System made more accurate predictions.
FTFY.
[Johannes Kepler pre-dated Newton. Newton built on his work. The accuracy was already there. Newton just explained how the gravitational force led to Kepler's Laws]