How have the IPCC's computer models performed?

[daveman]

Not so great, actually.

New paper finds computer models are inconsistent with temperature reconstructions of the past millennium

A new paper published in Climate of the Past finds that computer model simulations of past climate are not consistent with reconstructed temperatures of past climate. Thus, either the model simulations are erroneous or the temperature reconstructions erroneous, or both.

--

If we treat simulations and reconstructions as equitable hypotheses about past climate variability, the found general lack of their consistency weakens our confidence in inferences about past climate evolutions on the considered spatial and temporal scales. That is, our available estimates of past climate evolutions are on an equal footing but, as shown here, inconsistent with each other.​

So, the models can't even predict past climate.

How are they working on more recent times?

Not so great, actually.

New paper finds climate models cannot explain the global warming stagnation over past 15 years

A new paper by prominent German climatologists Dr. Hans von Storch and Dr. Eduardo Zorita, et al, finds "that the continued [global] warming stagnation over fifteen years, from 1998 -2012, is no longer consistent with model projections even at the 2% confidence level." In other words, there is a greater than 98% probability that climate models are unable to explain the stagnation in warming over the past 15+ years. The authors suggest 3 possible explanations for this:

1. the models underestimate natural climate variability

2. the climate models fail to include important forcings such as ocean oscillations and solar amplification

3. the models assume exaggerated climate sensitivity to man-made CO2

The authors point out that even if climate sensitivity to CO2 was greatly reduced future models, it is still "hardly feasible" that the models would reproduce the 15 year stagnation of temperature, stating, "a recalibration [with lower CO2 sensitivity] reproducing the reduced warming of the last 15 years appears hardly feasible." All of which suggests that CO2 is not the control knob of climate and natural variability is.​

So -- the models can't predict the past, and they can't predict the present.

Remind me again why I should trust them to predict the future...?

 

[Missourian]

Climate models wildly overestimated global warming, study finds

By Maxim Lott
Published September 12, 2013


Can you rely on the weather forecast?



Maybe not, at least when it comes to global warming predictions over short time periods.


That’s the upshot of a new study in the journal Nature Climate Change

that compared 117 climate predictions made in the 1990's to the actual amount of warming. Out of 117 predictions, the study’s author told FoxNews.com, three were roughly accurate and 114 overestimated the amount of warming. On average, the predictions forecasted two times more global warming than actually occurred.

Read more: Climate models wildly overestimated global warming, study finds | Fox News
​

 

[TheOldSchool]

Does carbon dioxide affect our atmosphere?

 

[daveman]

Does carbon dioxide affect our atmosphere?

Not as much as the models predict, apparently.

 

[TheOldSchool]

Does carbon dioxide affect our atmosphere?

Not as much as the models predict, apparently.

I hope so. At least for the next 5 or 6 decades. After that it can go ahead and affect shit as much as it wants!

 

[Missourian]

Does carbon dioxide affect our atmosphere?

I'd say so, but we only account for 5.5 percent of greenhouse gas emissions.

--------------------------------------------

This is from an older post:

Man-made GHG only account for 5.5% of total greenhouse gas emissions, the other 94.5% is naturally occurring.

And that calculation excludes water vapor as a GHG.

Just how much of the "Greenhouse Effect" is caused by human activity?
It is about 0.28%, if water vapor is taken into account-- about 5.53%, if not.

Global Warming: A closer look at the numbers​

Wikipedia has this

Quote:
Natural sources of carbon dioxide are more than 20 times greater than sources due to human activity.

http://en.wikipedia.org/wiki/Greenhouse_gas#Anthropogenic_greenhouse_gases​

They cite this UN Intergovernmental Panel on Climate Change page as a reference.

Vital Climate Graphics | UNEP/GRID-Arendal - Publications - Vital Climate Graphics
​

That corresponds with the 5.5% above...20 times greater equals 20 to 1 equals 100 to 5 equals 5%.



So if mankind gave up all fossil fuels, industry and livestock, built mud huts and returned to hunting and gathering, 94.5% of greenhouse gas emissions would remain because they are naturally occurring.


Is this true?

Quote: Originally Posted by Chris
Yes, it is true, but the problem is that CO2 stays in the atmosphere a long time, and if you add 8 billion tons of CO2 to the atmosphere every year, year after year, and you cut down trees at the same time, you are going to increase atmospheric CO2 by 40% in 200 years.

Quote: Originally Posted by Old Rocks
Yes, each year we add a small percentage compared to what nature adds. Yet nature also takes out a very large amount of what is added. It removes, through plant life, absorption in the ocean, more than it adds. But not enough more to make up for what we add. And that is how we end up with a 40% increase of CO2 over what that level was 150 years ago. Not only that, that represents a 30% increase over what it has been in at least 650,000 years, possibly in over a million years.

If you read the article on the Carbon 13 and 14 ratios, you will see how we can tell that the additional CO2 is from the burning of fossil fuels.

http://www.usmessageboard.com/environment/81382-greenland-glacier-recedes-10-miles-in-8-years-4.html#post1341995

 

[Abraham3]

That's an impressive bunch of numbers, but you missed one.

Isotopic analysis indicate that human emissions are responsible for 100% of the increase since 1870.

All those natural sources are very steady. Our emissions have grown dramatically.

I'd have thought that would have occurred to you as you were writing all that stuff. No, huh.

 

[Old Rocks]

These silly asses conveniatly skip the fact that the uptake and emission of CO2 was balanced until we began to burn fossil fuels. That 5.5% adds up rather rapidly, even when the ocean absorbs the most of it. We are at 400 ppm at present, up from the 280 ppm that we were at for centuries. That extra 120 ppm of CO2 is our creation. The CH4 was at 700 ppb for centuries, and that was the normal high in an interglacial period. Now it is at over 1800 ppb and rising. And in the time of a decade, CH4 is 100 times as effective of an GHG as CO2. Add in the manmade GHGs, many of which are several thousand times of an effective GHG as CO2, and we are over the equivelent of 500 ppm of CO2. Gonna get interesting.

 

[RetiredGySgt]

These silly asses conveniatly skip the fact that the uptake and emission of CO2 was balanced until we began to burn fossil fuels. That 5.5% adds up rather rapidly, even when the ocean absorbs the most of it. We are at 400 ppm at present, up from the 280 ppm that we were at for centuries. That extra 120 ppm of CO2 is our creation. The CH4 was at 700 ppb for centuries, and that was the normal high in an interglacial period. Now it is at over 1800 ppb and rising. And in the time of a decade, CH4 is 100 times as effective of an GHG as CO2. Add in the manmade GHGs, many of which are several thousand times of an effective GHG as CO2, and we are over the equivelent of 500 ppm of CO2. Gonna get interesting.

In other words even though the models used to predict the supposed future fail miserably we should still believe the scientists that insist on using them.

 

[IanC]

Methane is yet another example of climate model failure. The predictions for methane increase have been wildly exaggerated compared to reality yet they are incorporated into the calculation of future warming.

 

[Oddball]

How have the IPCC's computer models performed?

That's OK....They'll just change the numbers to comport with the new data, just like they have been all along.

All in a day's work in the sub-prime science of the globalcimatewarmercoolerists.

 

[daveman]

That's an impressive bunch of numbers, but you missed one.

Isotopic analysis indicate that human emissions are responsible for 100% of the increase since 1870.

All those natural sources are very steady. Our emissions have grown dramatically.

I'd have thought that would have occurred to you as you were writing all that stuff. No, huh.

This thread is about the utter failure of the IPCC's models.

 

[daveman]

These silly asses conveniatly skip the fact that the uptake and emission of CO2 was balanced until we began to burn fossil fuels. That 5.5% adds up rather rapidly, even when the ocean absorbs the most of it. We are at 400 ppm at present, up from the 280 ppm that we were at for centuries. That extra 120 ppm of CO2 is our creation. The CH4 was at 700 ppb for centuries, and that was the normal high in an interglacial period. Now it is at over 1800 ppb and rising. And in the time of a decade, CH4 is 100 times as effective of an GHG as CO2. Add in the manmade GHGs, many of which are several thousand times of an effective GHG as CO2, and we are over the equivelent of 500 ppm of CO2. Gonna get interesting.

This thread is about the utter failure of the IPCC's models.

 

[mamooth]

But the models have done superbly, once you adjust for ENSO, as one should do.

And if someone isn't adjusting for ENSO, they're fudging hard. And there's no point in speaking with a fudger, since you can't trust a word they say.

 

[skookerasbil]

[ame=http://www.youtube.com/watch?v=NBO2IstMi2A]CO2 is a trace gas. - YouTube[/ame]





Ooooooooops

 

[Abraham3]

CO2 is a trace gas.

Ooooooooops

God are you stupid.

 

[Abraham3]

Some actual data on the accuracy of IPCC projections


The Copenhagen Diagnosis

http://www.ipcc.ch/ipccreports/tar/wg1/pdf/TAR-12.PDF

http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf

http://pubs.giss.nasa.gov/docs/2006/2006_Hansen_etal_1.pdf

http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_3.pdf

Why Is Climate Sensitivity So Unpredictable?

http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf

 

[daveman]

But the models have done superbly, once you adjust for ENSO, as one should do.

And if someone isn't adjusting for ENSO, they're fudging hard. And there's no point in speaking with a fudger, since you can't trust a word they say.

Yes, I'm sure the climatologists who conducted the studies in the OP forgot to include the effects of a major climate phenomenon.

Maybe you should email them and tell them they're wrong. Don't forget to list all the papers you've had published so they know you know what you're talking about.

 

[daveman]

Some actual data on the accuracy of IPCC projections


The Copenhagen Diagnosis

http://www.ipcc.ch/ipccreports/tar/wg1/pdf/TAR-12.PDF

http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf

http://pubs.giss.nasa.gov/docs/2006/2006_Hansen_etal_1.pdf

http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_3.pdf

Why Is Climate Sensitivity So Unpredictable?

http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf

Papers by Hansen?

Yeah, HE'S got no financial turf to protect, does he?

Dismissed.

 

[percysunshine]

The IPCCs computer models will do what ever they're told to do. Rigging a model to give the answer you want is easy.