Dear Jennifer,
Here at ABC News Online, in an article titled 'Study shows more severe droughts ahead for Australia', is another example why there are so many cynics/sceptics about Anthropogenic Global Warming [1].
On the one hand the alarmists bang on about the fact that we are the cause of the increase in temperature over the last 100years, and if anyone raises questions about the role of the sun they get jumped on.
But now the academics are saying that the sun will affect our future prospects of drought or no, because they have a connection between sunspots and SOI and our weather.
Here is a delicious concept of one bunch of alarmists, with their "we are doomed because of drought caused by the sun", actually mucking up the argument of "we are doomed because it is Co2, and BTW the sun is not involved at all".
It would seem that the alarmists have some explaining to do.
Cheers,
Malcolm Hill
Littlehampton (where it is very cold and wet).
Australia
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[1] ABC Online: Study shows more severe droughts ahead for Australia.
New research into the sun suggests eastern Australia could face more severe droughts over the next 500 years.
Last Update: Wednesday, July 12, 2006. 1:36pm (AEST), http://www.abc.net.au/news/newsitems/200607/s1684681.htm
A study at the University of New England in New South Wales has shown a link between solar cycles and rainfall patterns, which can be used in conjunction with the southern oscillation index to more accurately predict droughts.
Associate Professor Robert Baker says ...
Paul - I have to say IMHO that Gavin seemed to rebutt any criticism made on solar bias.
There is a good discussion at;
http://www.realclimate.org/index.php/archives/2006/07/the-discovery-of-global-warming-update
about GCMs. The first comment is #43, and it's easy to follow the appropriate comments from then on. Martin Lewitt looks like a serious computer modeller. (But probably in the pay of Exxon.)
Paul - the models do exhibit some non-linearity in that they exhibit chaotic behaviour on input changes which is why they do number of runs. In some respects you have to admire systems that can generate cyclone like vortices and other aspects of the climate system if you give them sufficient resolution. These responses are "produced" not programmed for. Whether you believe the models depends on how well they do against a whole range of validation criteria. For example they are not that good at simulating El Nino (IMHO). I think the modellers know they can do some things well and others less well.
But given the real effects heatwaves, droughts, cyclones and floods already have on humanity you wouldn't want to move the balance on extreme events too far.
The problem becomes if you wait till the science is advanced to the level where someone like yourself will be more than convinced it will be too late to act. The CO2 will already be up there.
In any case I doubt we will act to mitigate (too hard) so we need to plan for adaptation. So we need to encourage the science effort here - not jeer and ridicule it to death.
It's a pity we can't get these discussions to a more positive constructive forward looking aspect. And I for one am not suggesting we go back the caves or wreck our economy to both adapt and mitigate. But we do need to do something.
Paul Williams - "But what if there are other factors not accounted for in the model? What if some of the values, ....."
I am sure that there are thousands of factors not taken into account as the atmosphere is thousands of times more complex than even the most sophisticated model. However you do not have to have 100% accurate model to make accurate predictions.
Here is an example. The model of the atmosphere used to design subsonic aircraft assumes that air is incompressible. Assuming this makes calculations possible using easy to use tools. Now you and I both now that you can compress air as you do that in your car tires however for all purposes of subsonic aircraft design air can be assumed to be incompressible and look at it planes do fly OK. The only place where the commpressibility of air has to be taken into account is transonic and supersonic flight. This is where designers around 1943 got into trouble as the aircraft they were then designing and operating were capable, in a dive, of transonic speeds and did not behave as they predicted. The Spitfire accidently had the best transonic performance of all and could be dived up to Mach 0.84 which testifies to the genius of its design.
But I digress - the point is that the models do not have to be perfect and all assumptions do not have to be perfect. Science usually only works on simplified models however that is sufficient for most purposes as the example I gave testifies to.
Ok Luke, apology accepted. I have no idea what you mean by b/s-ing or lack of full disclosure, I am just an interested onlooker with a point of view. I have no employment or financial interests with anyone who is involved in climate research or any type of energy production or policy making.
The point I am trying to make about the GCMs, which both you and Ender seem to miss, is not that they are being cooked to get a predefined answer, but that when actual data turns out to be different to the model's predicted data, then obviously the model is wrong in some aspect. Presumably the modellers then look for what they may have missed or got wrong, and try to improve the model. This seems commonsense, agreed?
The new and improved model then would be tested to see how well it conformed to historical data, and if it was a good fit, used to predict future conditions under a range of scenarios.
But what if there are other factors not accounted for in the model? What if some of the values, such as the climate sensitivity of CO2, are wrong? From my very basic understanding, models do not allow for non-linear changes, so while they may be a useful study tool, the predictions of doom which the media and some policy makers have extracted from the models probably can't be supported with sufficient certainty to justify changes to energy policy, etc.