Quote:
Originally Posted by AdamLein
Cam, the jury is still out for me as to whether warming is occurring. As you are pointing out, I've seen a variety of evidence pointing both directions. My personal, anecdotal experience says that it is indeed increasing, but even if that's true, I recognize that there are huge swings in the annual mean temperature.
What I'd be interested in seeing is just how huge those swings are, relative to the overall increase over the past hundred years. If there's a two-degree swing every couple of years, then a two-degree increase over a hundred years is not interesting either. In statistical terms, given the assumption that there is no warming going on, what's the probability of observing temperatures as extreme as we're seeing? My guess is: pretty high.
Does anybody have a link to numerical temperature data over the past hundred years or so?
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Adam...the ONLY 100year temp data is from NASA/GISS since the satellites were not flying till the 70's. The problem with the NASA/GISS data is that it is QUITE unreliable even today. Back in the early 1900's and before, there was no real accuracy of the sort needed today and you have to remember that the temps recorded were designed for local weather reporting...not accuracy. Furthermore, without an understanding of the macro events surrounding a year or years, it is impossible to evaluate the temperatures. For Example...an El Nino or La Nina event or a volcano eruption can cause great swings in temps for a couple of years. Also the growth of cities and parking lots and highways etc. causes significantly higher temps in some spots when compared to the same areas 50 or 100 years ago...the is the "heat island" effect.
So...when you see the temperature graphs like I posted, the RAW data is rather meaningless and it has been massaged to wring out the anomalies and then the 5 year smoothing is applied to take out the peaks and valleys and provide a better overall picture of temps.
Having said that...the BIGGEST problem with the GISS data is that the PRESENT temp monitoring sites are hugely inaccurate with only 13% of the stations accurate to within ONE degree according to their own standards!
Only the blue and green sectors of this pie chart are within one degree accuracy. The large organge swath is greater than two degrees and the 13% RED...is 5 degrees or more!! So we are trying to measure temperatures to an accuracy of a 1/10th of a degree or so...and using equipment siting that is orders of magnitude more innaccurate.
This is why I say...only trust the satellite and ocean temp measurements...and even then...check who is messing with the data and how.
Anyway...I think you have a perfectly reasonable stance to say.."I don't know who to believe" at this point in time. I personally think that there is probably some slight warming that has gone on due to 95% natural causes AND that we are in for a number of years of cooling coming up due to solar issues. In either event...it is not a crisis for mankind and we have a lot better things to do with our money than fix imagined crises.