Timeline for Did the IPCC obfuscate the evidence in a way that obscures the discrepancy between previous climate models and recent observations?
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10 events
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| Oct 10, 2013 at 11:33 | comment | added | user18604 | @gerrit, now one closer to the target! | |
| Oct 10, 2013 at 11:22 | comment | added | gerrit | @DikranMarsupial The only way to prevent that is if experts take part from an early stage. It still needs (at least) 114 more to commit to doing so. | |
| Oct 10, 2013 at 10:42 | comment | added | user18604 | Indeed, IIRC the available evidence suggest that climate (i.e. long term statistical behaviour of the weather) is essentially non-chaotic. The Geoscience SE sounds like a good idea, but I am concerned that it will end up as yet another forum dominated by rhetorical squabbling, rather than discussion of science. | |
| Oct 10, 2013 at 10:12 | comment | added | gerrit | I'm waiting for the Geoscience SE. I've been confused for a while as to climate is chaotic. Weather certainly is (but that's an initial value problem), but climate, being a boundary value problem, I don't quite understand. This betrays a misunderstanding of the difference between weather, which is chaotic and unpredictable, and climate which is weather averaged out over time.. But indeed, that question is beyond the scope of this question. | |
| Oct 10, 2013 at 6:46 | comment | added | user18604 | As I said in my previous comment, you need to understand the basic principles of the models operation in order to know how to interpret the output. This is not a good forum for an in-depth discussion of this, but I would be happy to discuss this with you at a more suitable forum, such as skeptical science.com, perhaps this would be an appropriate thread skepticalscience.com/climate-models.htm | |
| Oct 10, 2013 at 6:44 | comment | added | user18604 | @matt_black The climate system is chaotic. That means that its exact behaviour fundamentally cannot be predicted, because we cannot measure the initial historic observations with perfect accuracy and resolution. That means you can only simulate weather, not predict it. This means that there will be different cycles of internal variability in each run. Adding an offset to bring them into agreement does not initialise them with actual historical observation, and will not synchronise the cycles of internal variability within the models. | |
| Oct 9, 2013 at 21:53 | comment | added | matt_black | @DikranMarsupial In any other sphere a model of the future would be initiated with actual historic observations and one of the ways of judging the model's quality would be whether it self-corrected from a starting point that was a random high or low. Switching from a start point that is fact to one that is partly opinion (which years feed the trend?) seems like allowing arbitrary after-the-fact judgements to post-adjust the forecast. | |
| Oct 9, 2013 at 17:23 | comment | added | user18604 | Yes, it is hard for an outsider to understand these issues without first learning what a climate model does and how it operates. They are essentially simulations of the plausible weather that we could observe for a given set of forcings (e.g. changes in atmospheric CO2, solar output, etc.). Just as in real life there will be warm years and cool years within the general long term trends. There is no reason to expect these variations to be syncronised between model runs or between models and observations, hence they don't agree exactly at any point. There is always some uncertainty. | |
| Oct 9, 2013 at 16:47 | comment | added | gerrit | It is quite clear that the models are not all in perfect agreement about 1990. For an outsider, it may be confusing why models do not agree about years where we have plenty of measurements. It may be worth noting that climate models do not use measurements (as opposed to weather models and closely related reanalysis models). | |
| Oct 9, 2013 at 16:10 | history | answered | user18604 | CC BY-SA 3.0 |