Originally posted by OzWeatherman
Fact is that globally, over the last 2 or so years, the Earth has actually cooled significantly. Wether we will see this trend continue is anyones
guess....but in my opinion, I think the global warming issue may have been inaccurate after all.
Actually expected better from your goodself, Oz. From others here, I do expect statistical and scientific naivete (along with obfuscation,
misrepresentation, willful ignorance etc etc).
You make a number of inane claims here. Firstly, I know weather might be your thing, but climate is more than 2 year trends. A quick look at numerous
2 year periods in the past would show cooling and warming - might as well fling dice as to make predictions from such data.
Try woodfortrees to play around with the data from HadCRUT, NASA-GISS, RSS-MSU, or UAH. To put
any inferential weight on such timescales is
ridiculous.
Moreover, you then ask whether the two year 'cooling' trend might continue. Well, it takes less than 4 or 5 clicks to see the trend since 2008 is
actually upwards. By the end of this year, the two year claim will now be of warming, lol.
So the claim of a supposed 'fact' of 'significant cooling' for the last 2 years (or so) is also ridiculous. The linear trend from 2007 to current
day is negative (giving you the positive 'or so' part), but then you say 'cooled significantly' - what you mean statistically significant?
Unlikely, perhaps run a Pearson's r and see what you get. Funnily enough, run it from 2008 to current (20 months), we get a positive trend (which
would likely be p < .05 on eyeball). So even with the negative trend from 2007 it's neither significant statistically (bet ya, seen enough
scatterplots) nor practically.
Climate is assessed on longer term scales, and the easiest way to measure deviation from the long-term trend is by using the residuals. They show no
recent growing deviation - entirely lying within the noise of the last few decades. Here's an easy illustration, this data shows the trend from 1970
(40 years), 1980 (30 years), 1990 (20 years), 2000 (10 years) to current; along with the 10 year trends for 1970-1979, 1980-1989, 1990-1999. The noise
in the shorter scale data is obvious, but all lie within a longer term trend - go try the same for anything less than 5 years, lol.
The absolute best that can be claimed is that there has been a short term stasis, but just really the normal noise that has been obvious a number of
times over the last 30 years of long-term warming. Given we've had a La Nina along with quiet solar activity, these cooling biases have most likely
just taken the edge off the longer-term warming - nothing more, nothing less.
To see a claim of inaccuracy from you, determined from an vacuous interpretation of 2 years (or so) data, is pretty sad. And then add the cherry of
S&Fing an OP which wallows in cherrypicking (why 11 years? Why not 10? 12? 13? 14? 9? 22.75? And I assume HadCRUT not GISS, lol) and pushing cranks
like Piers Corbyn.
Hey-ho.
[edit on 11-10-2009 by melatonin]