|
Post by nautonnier on Jan 22, 2010 14:11:17 GMT
For a long time I've thought this time period would usher in a colder period based on solar cycles and past historical temps. It could still happen. Sentient has posted a site which i've read and find very interesting. www.clim-past-discuss.net/volumes_and_issues.htmlI think there is a multi-centennial natural pattern as well. But to predict it one needs to know what causes it. I figure its likely the sun but it doesn't appear we can as of yet predict future solar cycles with any degree of reliability. Wiggle review seems to be the primary pastime. Looking at the various proxies it appears one can see signs of cycles but it is pretty difficult to find anything that even remotely suggests which century things might change. When you think of it the past century ostensibly brought us about a .5 degC warming. The linear trend line drawn through the Hadrut3 global data 1860-2009 gives you a .72degC increase in temps. That works out to a .48degC/century slope. Not very significant especially when it seems our super modern climate monitoring system has difficult keeping within half that difference month to month from one service to the next even with all the modern technology we have. The problem is that the climate is a chaotic system. Yes there are cycles mainly driven by the Earth's rotation around a precessing axis on a variable elliptical orbit with a moon orbiting around it the pair of bodies orbiting about a barycenter which is also orbited by other planets and the Sun which blasts the parts of the Earth facing it with all sorts of energy at varying rates as the Sun follows its epitrochoid orbit around the barycenter. Meanwhile the surface of the Earth is covered mainly by water which has convection currents affected by the Coriolis force leading to complex differential rotation and convection and the thermohaline currents around the continents, above this is the chaotic atmosphere that has varying quantities of the main 'green house gas' water vapor following the hydrologic cycle and traces of other GHG. The atmosphere itself a chaotic turbulent fluid affected by gravitation, major convective cells and minor convection, moderated by the Coriolis forces ...... With such a chaotic system it is not possible to have purely linear effects. Every now and then the huge set of variables are lined up just right and just at the right time some other event occurs and the climate system flips to the other one of its stable states. It has two. The most stable is ice-age, the less stable are the interglacial. This would suggest that the trigger to move the system from the current attractor is more common in the interglacials or that the interglacials are not as strong an attractor. This flipping between states has been happening for millennia with hugely varying levels of CO 2 and with no correlation between CO 2 levels and temperatures. What would be interesting research would be to find the set of variable states that precede flips or rapid changes in climate - such as the D-O events. Then humanity may have an idea when to tense up and hold tight.
|
|
|
Post by spaceman on Jan 22, 2010 16:30:50 GMT
how much heat would it take to melt the west Antarctic ice sheet. If it raised the sea level 20 m, that is a whole lot of heat. Where is it coming from and what's causing it. So far, as I can see, ice reflects a lot more than just sunlight. The water in the Great Lakes here in the US warmed recently, AGW was ruled out as the cause. Warming the ocean and melting the ice would involve Richter scale types of warming. I was thinking maybe there could be a connection between magnetic monopoles. So if the crystals in the ice line up, the magnetic flux running through them could cause the ice to soften and melt Not that regular ice is spin ice, just a variation. Coldness may be a factor as well. In short, ice could be like the wire in a toaster. When the magnetic field moves through ice , it warms up. Something like a critical mass when the ice sheet becomes so large, it would be like a trigger. Enough heat is generated that a great deal of the ice melts.
|
|
|
Post by jurinko on Jan 24, 2010 19:36:37 GMT
Tropics are up and down per Nino/Nina but basically flat, southern hemisphere is just water + some Darwin Zero stations. Northern hemisphere runs the show. In few years, we are back in 80ties, average of LIA.
|
|
|
Post by aj1983 on Jan 24, 2010 19:46:43 GMT
The eighties the average of the LIA? So there was no LIA after all (or was the LIA a warm period??). I'm sorry but I'm having trouble understanding some AGW skeptic reasoning I think... please explain.
|
|
|
Post by icefisher on Jan 25, 2010 2:47:51 GMT
When you think of it the past century ostensibly brought us about a .5 degC warming. The linear trend line drawn through the Hadrut3 global data 1860-2009 gives you a .72degC increase in temps. That works out to a .48degC/century slope.That could be a misleading calculation. For example let's say temperatures increase another 0.5 deg in the next 40 years. You could argue that's 1.22 deg since 1850 - or just 0.61 deg per century - not that much different from the established (0.5 deg/century) rate. However, it would be obvious that there had been a 1 deg increase in ~75 years and quite clear that the previous cycles had been broken. Lets see if it happens first before we worry about the content of the debate 40 years from now.
|
|
bxs
Level 3 Rank
Posts: 115
|
Post by bxs on Jan 25, 2010 2:50:22 GMT
When you think of it the past century ostensibly brought us about a .5 degC warming. The linear trend line drawn through the Hadrut3 global data 1860-2009 gives you a .72degC increase in temps. That works out to a .48degC/century slope.That could be a misleading calculation. For example let's say temperatures increase another 0.5 deg in the next 40 years. You could argue that's 1.22 deg since 1850 - or just 0.61 deg per century - not that much different from the established (0.5 deg/century) rate. However, it would be obvious that there had been a 1 deg increase in ~75 years and quite clear that the previous cycles had been broken. Lets see if it happens first before we worry about the content of the debate 40 years from now. Icefisher, r u even going to be alive then? ;D
|
|
|
Post by jurinko on Jan 25, 2010 10:35:31 GMT
The eighties the average of the LIA? So there was no LIA after all (or was the LIA a warm period??). I'm sorry but I'm having trouble understanding some AGW skeptic reasoning I think... please explain. climate4you.com/CentralEnglandTemperatureSince1659.htmCheck the CET record and see that LIA average was not much different from 80ties. Of course, there were frequent occurrences of extremely cold years, but also as warm as today.
|
|