> Retrospectively comparing future model projections to observations provides a robust and independent test of model skill. Here we analyse the performance of climate models published between 1970 and 2007 in projecting future global mean surface temperature (GMST) changes. Models are compared to observations based on both the change in GMST over time and the change in GMST over the change in external forcing. The latter approach accounts for mismatches in model forcings, a potential source of error in model projections independent of the accuracy of model physics. We find that climate models published over the past five decades were skillful in predicting subsequent GMST changes, with most models examined showing warming consistent with observations, particularly when mismatches between model-projected and observationally-estimated forcings were taken into account.
"External forcing" means basically CO2 level. They adjust model projections for errors in projecting CO2 increases. So what they're testing is just the physics of the models.
Lol, you could have simply projected the warming from 1900-1940 and been in that confidence interval.
The planet is warming, and CO2 is drastically exasperating it, but our data and models are crap. Look how many fights and researcher nerd wars have happened over something which sounds trivial like satellite altitude drift or locating ground stations, and you'll see compromise, number fudge, magical constants, and the typical amount of statistical shenanigans.
I am cheered to see that we are applying the fundamental test of good science to a very political topic.
I would be interested to see how recent climate models differ from the (proven able to predict) models from the 70's. Logically, one could make an argument that we should trust the predictions of the (earlier, simpler) models of the 70's than the more recent ones, which are analogous to new medicines which have not been through a double-blind study yet to prove that they are better than the old standard.
Because nobody listens to the scientists. You have two sides where one side thinks we should sacrifice (all) economic growth for the sake of the planet and another that thinks we should sacrifice the (entire) planet for economic growth. The future will hopefully look nothing like either of them. We should find a healthy balance between the two and that means we need a self regulating system and preferably it should resemble something we already have. Landfills charge for disposing of garbage so why not charge for atmospheric pollution? It already exists and is called the Kyoto Protocol.
In the US many (most?) prominent members of the Republican Party (our right wing/conservative political party) deny the existence of global warming/climate change.
There was a NYtimes article showing that the denialism has been happening in all three english speaking countries: US, England and Australia, because of brainwashing.
Of course, nobody wants to hear they are the useful idiot that fell for it, but we can't let that stop us from pointing out reality.
As far as the Republican party goes, I'm sure there are many who do believe in climate change, however they have to fall in line and so they will not speak up. The Republican party is known for presenting a "unified" message.
I am cheered to see that we are applying the fundamental test of good science to a very political topic.
Are we, though? I'm not at all sure that we are. Actually climatology seems to be ridden with disturbing and unscientific practices that somehow they get away with, although it would all be totally forbidden in other fields.
Two huge problems.
Firstly, no, the models didn't correctly predict future temperatures. The prior predictions were wrong. What's actually happening is that climatologists have gone back and adjusted old models to take into account what actually happened, and are now claiming they were making accurate predictions all along:
"This study’s accounting for differences between the projected and actual emissions and other factors allowed a more focused evaluation of the models’ representation of Earth’s climate system"
Not just adjusting for lower levels of CO2 emissions but also, note, "and other factors". That's not how predictions and models work, is it? You can't just go back and edit your old predictions to make them accurate and then claim you were super good at forecasting. The whole point of forecasting is to make predictions about the future. "I would have been right if only I'd known that ...." is the same thing as being wrong.
Secondly, this type of rewriting-the-past is happening here because climatology keeps getting away with it in other contexts. The worst by far is the way temperature records are constantly rewritten in ways that not only create warming where prior timeseries didn't have them, but which routinely invalidate decades of prior climatology.
Look at that temperature graph in the story. The observations line shows a steady upwards trend: the world has been getting hotter at a steady rate since 1970.
But this time series for temperature directly contradicts the global temperature time series from very recently, which showed a "pause" or "haitus" in global warming. Huge amounts were written about this completely unpredicted, unmodelled and difficult-to-explain near 20 year period of flat temperatures. For instance:
"As many people know, the warming of the earth’s surface has slowed sharply over recent years. That slowdown did not match past computer projections of what the climate was supposed to do under the influence of greenhouse gases, and scientists have been struggling to explain it."
So six years ago "many people know" that warming of the Earth's surface has slowed sharply and that this "did not match past projections". Now look at today's story in 2020. It shows a graph of observations since 2004 with no sharp slowing, and apparently most of the model projections were right.
The combined Land/Ocean graph is flat at an average annual anomaly of 1 degree farenheit between 2000-2010.
Now look at that graph vs the one on the "Study confirms" page and you can see they don't match: they both claim to be global records of average temperatures but the shape is different. It's logically impossible for both graphs to be right.
This happens because climatologists edit old temperature datasets in ways that bring the data in line with their models. They then present the edited graphs of long term temperatures without mentioning that this has happened. This graph starts in 1970 although records go back much longer because at the start of 1970 scientists were talking about global cooling, why, because the global temperature graphs they had showed the world had been getting cooler for 30 years. The decline was steep enough to create great concern, there were international collaborations between the USSR and USA for instance. Nowadays that 1940-1970 period of decline is gone. It looks either flat or just slightly climbing on modern graphs - and thus nobody can understand why global cooling was ever something scientists worried about.
I'm sure I'll get downvoted to hell for all this but people need to know. Scientists who have doubts about their data should either show error bars or simply discard the data and refuse to make predictions based on it. They shouldn't edit the data to remove deviations from models and then present it as evidence they were right all along. It's quack science.
Why was blargmaster33's comment killed within 1 minute of posting? Which guideline does it violate? What rule does it break? Most importantly, if it is a false statement, what proves that it is so?
And we’re all surely missing the thoughts of blargmaster featuring such insights as “Pinochet did nothing wrong” and “The only good communist is a dead one” and “God bless the Spanish for expunging this evil from existence” where “this evil” is the Mayan people.
Abstract
> Retrospectively comparing future model projections to observations provides a robust and independent test of model skill. Here we analyse the performance of climate models published between 1970 and 2007 in projecting future global mean surface temperature (GMST) changes. Models are compared to observations based on both the change in GMST over time and the change in GMST over the change in external forcing. The latter approach accounts for mismatches in model forcings, a potential source of error in model projections independent of the accuracy of model physics. We find that climate models published over the past five decades were skillful in predicting subsequent GMST changes, with most models examined showing warming consistent with observations, particularly when mismatches between model-projected and observationally-estimated forcings were taken into account.
"External forcing" means basically CO2 level. They adjust model projections for errors in projecting CO2 increases. So what they're testing is just the physics of the models.