How confident are you in the accuracy of climate models?
Do you think they’re generally accurate? Worthless? On what do you base this conclusion?
Here is one scientist’s take:
Many of the comments to previous blogs have stated that models are “just” a set of assumptions, and that the processes in the Earth’s climate are so complex that they defy our attempts to model them with any rigor. There are assumptions that are made when models are built, but those assumptions are not simply pulled out of a bag of magic tricks. In fact, arbitrary, unjustified assumptions are generally repelled from the modeling community because, first and foremost, the models need to describe some set of observations and the evolution of those observations, i.e. prediction. Most components of models are, just like my original modeling efforts, a representation of mathematical equations that rigorously describe the motion of the atmosphere. The idea that I and my colleagues would work from some potpourri of unjustified assumptions is, in fact, a bit offensive.
http://www.wunderground.com/blog/RickyRood/comment.html?entrynum=57&tstamp=200801
Jello, welcome to our side.
http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png
I’m fairly confident that the climate models used by the IPPC are generally accurate.
A) They are not scribbled out on cocktail napkins; model fundamentals are based on established physical laws, such as the conservation of energy, momentum, and mass, and processes, such as those of orbital mechanics, as well as parameters for such things as equations of fluid motion and formulas for evaporation as a function of wind speed and humidity. [1] Because parameters are involved, there is a range is possible outcomes. According to the IPCC, the temperate will rise by 1.1 to 6.4°C by 2100. The most likely increase will be between 1.7 and 4.4°C.
"Deniers" limit themselves to one or two possible outcomes: "the globe won’t warm anymore", to "global warming to be good." It is obvious as to who’s climate model is more representative of the real world.
B) Today’s models have been able to fairly accurately simulate climate of the past, such as the ones used by the IPCC which began its run in the year 1900 and successfully simulated temperature change during the 20th century.[2]
C) We will never have a climate model that is 100% perfect. “That doesn’t mean or imply that they are not helpful, or needed. This just means that the models will, however, never meet all the demands that have been placed on them, including those by the debunkers who want all action delayed until the perfect model or ensemble is at hand.”[3]
Look at who pays the bill, thats how the data come out.
Science bent to fit your needs.
50/50
It depends. How accurate are they to predict the climate 1month from today, 6 months, 1 year, 5 years from now?
If they can accurately post cast data in the past, then they should also work in the future.
However they can’t. So I guess the models aren’t accurate at all.
Isn’t it true that increased CO2 leads to global cooling? The climate is MUCH more complex than any scientist can comprehend. There are only very small pieces studied.
The models are coming to pass, but they are based on figures from the 1990′s, and the rate of CO2 increase per year has increased from the 1.3% of the 1990′s to 3.3% every since 2000. look for their 50 year changes to hit in the next 3-8 years!
Get a copy of USA TODAY, TUESDAY, OCT 23, 2007 PG 5D upper right hand corner art. by Doyle Rice. Title: "Researchers say CO2 emission accelerating… Faster rate isn’t used for climate predictions" He listed source as "Proceedings of the National Academy of Sciences.
Also, the oil companies are spending billions to keep the true information muddied for the next 5 years so you will not figure the oil is about to run out… and they are buying up all the alternative energy source products as fast as they can…
There are hundreds of scientists worldwide who have dedicated their lives to learning, understanding, and researching the cause and effect of climate change. When you have a near consensus among those scientist as to that cause and effect, I am like to want to listen to what they have to say with an open mind and the idea that they might know what they’re talking about.
I am sure the scientist know what they are doing. And would not make random claims if they could not back it up.
A survey conducted by two German climate scientists shows that most of the climatologists do not base much trust in the polls.
The survey asked scientists to indicate “the degree [to which] you
think the current state of scientific knowledge is able to provide
reasonable predictions of climate variability of time scales” of 10
years, 100 years, and greater than 100 years.
Only one-third (32.1 percent) of scientists reported having
confidence in our ability to make predictions of time scales of 10
years, while more than half (53.3 percent) reported little or no
confidence. When asked about time scales of 100 years, slightly
more than a quarter (27.4 percent) of scientists reported being
confident while 55.6 percent had little or no confidence.
Asked to respond to the statement,
“Climate models accurately verify the
climatic conditions for which they are
calibrated,” barely half (46.8 percent)
of scientists agreed, 17.6 percent were
uncertain, and more than a third (35.6
percent) disagreed. Four times as many
scientists “strongly disagreed” with the statement as “strongly
agreed” with it.
For a complete list of questions and answers to many other questions including are human causing climate change you can read the responses here.
http://downloads.heartland.org/2086111.pdf
From my own experience with computer models of fairly complex systems, I know for a fact that they can achieve excellent predictive capabilities when done well. And from what I’ve seen and read, the models now in use are quite good. Once you understand how modeling works, it’s no longer a black art and you appreciate their capabilities and limitations.
A nice history of climate modeling can be read here:
http://aip.org/history/climate/GCM.htm
And a good article on Hansen’s models accuracy from 1988 can be read here:
http://www.realclimate.org/index.php/archives/2007/05/hansens-1988-projections/
all depends on who is putting out the reports…what spin they want… no different that the major tv companies essentially giving lots of face time to a presidential candidate to get them elected!
I’m not very confident. They are as good as man’s current understanding of the climate.
at this point, the models work quite well.
they’ve been tested, and predicted weather that actually did occur.
the main problem is, how much CO2 will be released in the future?
will the USA build enough nuclear plants to avoid having to use large quantities of coal?
will Calif be allowed to limit CO2 tailpipe emissions?
will the expected increase in the value of the Chinese yuan slow their manufacturing growth, and thus their rate of increase in CO2 emissions?
don’t you wonder about responses? odysseus <<Look at who pays the bill, thats how the data come out. Science bent to fit your needs.>> that’s how politics works, not science. and wall street, apparently.
jello: <<If they can accurately post cast data in the past, then they should also work in the future. However they can’t.>> uh, wrong, they can. they have. the models are accurate. the only question concerns the data input in the future.
kirkill: <<Isn’t it true that increased CO2 leads to global cooling?>> no, warming. that’s what this is about. that’s the measured changes, and the observed effects.
<< The climate is MUCH more complex than any scientist can comprehend.>> It is more complex than you can comprehend. fortunately, it’s not you that we need to depend on. <<source oism>> you’re kidding.. oh no, it’s kirkill, you’re not.
skyhawk: <<Generally not accurate …. Oh, my conclusions are partly based on the opinions of professional meteorologists who provide data to the oil and gas industry.>> (A) weather is not climate. (B) who do they work for? *sigh*
eric: heartland.org or Nobel committee. gee, that’s a hard one. OR NOT!
ken: good luck. you’ll need it.
Well it was this image that got my attention in the first place
http://geog-www.sbs.ohio-state.edu/courses/G520/bmark/19-17.jpg
and this image said to me that I should study the earth and its systems http://www.scienceblog.org/images/climatechange.png
You might say climate models have cost me thousands of dollars in tuition. So I guess I have to say that I trust them.
While I feel that climate models will give us general long term trends, I do not feel confident that any given year in any given place will conform closelu to the model.
We could see massive snowfalls based on the data we are seeing, and those snowfalls could produce local or even global cooling for periods, as we are seeing in Antarctica now. But as the snow falls it releases enormous amounts of heat. The model correctly indicates that the heat will build to the point of clearing the snow, unless we get a lot of volcanic activity .
Our models do not anticipate any large volcanic eruption causing cooling.
I don’t think they are very good.
I had a physics professor who said he started out to be a meteorologist. He found that with all the weather stations and satellites and computers that meteorologists could predict the weather with 95% accuracy, but if you just asked an untrained person who had lived in the same place for 10 or 20 years, he could look at the sky and feel the air and predict the weather with 90% accuracy. My professor figured a 5% improvement was not worth the trouble so he changed his major to physics.
They’re worthless.
These same scientists use models to try and predict how many hurricanes will form each year (they weren’t even close the last two seasons). They can’t predict within 100 miles where a hurricane will make landfall 5 days out.
These models make assumptions based on historic data to guesstimate the future under similar circumstances. If we’re treading uncharted territory, that defies any past data, no? Except they build the models to include the anomalies and claim it works NOW….no, NOW….no, NOW….
The margin of error compounds the further out you go into the future. If they completely drop the ball every year, why in the world do you think they can predict decades out with ANY accuracy at all?
There are so many variables involved in the the models the minor differences in input create wildly differing results. Scientists can’t even agree on all of the variables affecting climate change!! With so many "unbiased" scientists involved with the collection of raw data at all of the remote sites around the world, I do not trust the numbers to be accurate enough to accurately conclude the entire planet warmed one degree in a hundred years.
I think it is another pile of bologna!! These historical cherry pickers should be sent to E 14 th. St, in San Leandro, CA to explain their science to my Homies!! Yo, yo, yo! I guaranty that their ride would be stripped in 5 minutes! Whazzz up!!! Yo, yo ,yo!
The models that they have been able to create have only been on computers. After creating the models, all attempts to recreate the studies in a laboroatory setting. The so called scientists are not working with actual facts that can be proven, which is what real science is, a theory that is proven. The reality if the whole Global Warming scam is that people need to follow the money. Who is paying for the research, the people who say that it is real. Well if you give a drunk $20 and tell him to announce to everyone that he is the president, guess what, He will do it. Al Gore and the questionable scientists are those drunks, and the man with the money is a world government, and the UN is right in the middle of it for political and economic reasoning.