ican says:
Quote:This clearly suggests that these oscillations are caused by something other than increases of CO2 density in the atmosphere. Therefore the temperature oscillations both groups have been reporting are unlikely to have been caused by what both groups have clearly, irresponsibly jumped to conclude
OF COURSE, other things than CO2 have an effect on temperature
TOO. THAT'S WHAT WE'VE BEEN TELLING YOU FOR MORE THAN A YEAR NOW. IT'S A MULTIVARIATE SYSTEM. Anytime you have a system with many variables, only one of which is linear, and you expect the combined outcome of all the variables to be linear, you are an idiot. That lack of linearity doesn't mean that variable isn't having a significant effect. It only means you haven't the foggiest idea what you're talking about.
Somewhere in your alleged experience, ican, you must have had some experience with combining curves on graphs. Imagine a straight line with positive slope. That's representative of the effect of a linear increase of CO2, a greenhouse gas, on temperature over time, as the laws of physics have shown since Svante Arrhenius.
Now think of everything else that effects temperature (this is nowhere near an exhaustive list--there are probably hundreds of things, some major, some so nit-picking small it's impossible to show their effect at all, nor are any of these necessarily operative now--Milankovich cycles, the precessional changes in the earth's orbit which act as atrigger for ice ages, only affect us every hundred thousand years or so, for example).
These would include, for example, changes in other greenhouse gases, notably water vapor and methane, changes in albedo (e.g. land use change or melting of the arctic ice cap), changes in insolation, volcanos discharging huge amounts of particulates which block sunlight (The Year Without a Summer, somewhere around 1819, for example), air pollution and smog, chemical releases which deplete ozone (another greenhouse gas), summer and winter, the sunspot cycle (which produces a cyclic change if I remember correctly of about a 20th of a degree C, up and down over 11 years or so). All these and many more produce a picture of temperature change over time rather like the silhouette of an old mountain range--worn peaks and valleys, undulations up and down, usually not a great aggregate change over time up or down.
Now add the two curves. What you get is a composite that has all the peaks and valleys of the other variables but rises over time. You'll still have the valley there, but it's walls will be higher and it's floor will be higher by the amount added by the increasing CO2. And that is what the graphs of global temperature show--rising over time, with peaks and valleys.
And in terms of weather effects on global temperature, the largest single weather event in the world, ENSO, has a significant, tho transient (because it's WEATHER), effect on global mean temperature. When it's a la Nina year you get a cold spike below average global temp, and when it's el Nino (warm water rising), a warm spike is superimposed on the (rising) average temperature--as in 1998-98, which was for 6 or 7 years the warmest year on record and was also the strongest el Nino on record. 2005 dethroned it as the warmest year. 2007 was the warmest year on record on land and likely would have dethroned 2005 except that a pretty strong la Nina developed late in the year and lasted into June (which is your period when temps were lower).
Now I first brought this up here last year some time, before the la Nina event I believe, which means my prediction of what would happen in such an event has proven true.
To utilize Foxfyre's terminology, everytime there's a cold spell (and this isn't even a cold spell--it's a just-a-little-cooler spell but still warmer than anything before the mid-90s), the anti-global-warming religionists say, see, there's no global warming and it's safe to bury our heads in the sand again. Nope, it's just weather. It'll pass.
