Tuesday, June 09, 2009

Climate change denier redefines the number 10

A magic moment in the history of troll; it may never come again.

OK, so you know the climate-change denier talking point about global warming supposedly "stopping" in the last ten years. It's a classic example of how to lie with numbers; you just choose the bit of the data series that suits you and forget the rest. 1998 was really hot, so you start the chart there, and presto, a flat or declining trend. Learn about it here. Of course, the facts that it was rising steadily before '98 and has been rising steadily since then, and that the best evidence that something isn't rising is not that there has been an all-time high value recently are ignored.

Now, well, 1998 isn't ten years ago any more. So, I was wondering if any of the trolls would be sighted claiming that global warming has stopped in the last ten years, now their own talking point doesn't make sense even on its own terms. Enter David "no-one could be better named" Duff with a genuinely duff performance.
Incidentally, ‘Little Willy’, what’s happened to all that global warming in the last 10 years? No, on second thoughts don’t bother replying to that, your written equivalent of the clicks and grunts of a Kalahari bushman is simply too, too, tedious.
Oh, mate, that's your Prime Directive ("Don't be such an arse about it") violated right there, with a good dollop of racism chucked in.

But for our purposes, look at the chart here; if you start measuring 10 years ago from today, in 1999, you get a warming trend of almost 0.4 degrees C, about four times greater than the linear regression would give you! DOOOMED I tell you!

Quite an achievement; you'd think that repeating talking points was within anyone's abilities, but we've found a troll who can even bollocks that up. FAIL.


David Duff said...

Good morning, Alex. I hadn't realised that your were the infamous 'Yorkshire Ranter' - I should have guessed!

Perhaps your reader would care to glance at this link (the correct one this time - sorry for the error) which displays Dr. Hansen's *own graph* in which he made his, er, historic forecast to Congress of rising global temperatures just over 20 years ago. Unfortunately, some cheeky so-and-so has had the temerity to scribble - in red ink! - the actual temperatures.


"Shome mishtake, surely!"

Alex said...

You haven't addressed the point, nor read it.

David Duff said...

Now, now, no need to sulk! You complained that my dates were incorrectly chosen so I went to your favourite Guru and used his dates and his forecasts.

Suddenly you have nothing to say!

guthrie said...

Nope, that doesn't surprise me, Duff is well known for acting the idiot.

bluegrue said...

David Duff,

the graphic on your page is seriously skewed in several ways, or in other words: plain wrong.

Let me explain:

You are obviously using RSS MSU lower troposphere data instead of surface temperature, judging from the shape of your red curve and your post.

a) You are comparing monthly data to annual data. The former has a much higher variability than the latter. Why don't you just use annual data, so that you at least appear to compare apples to apples?

b) You fail to correct for the different baseperiods of Hansen's prediction (1951 to 1980) and RSS MSU (1979 to 1998). Judging by comparison with GISTEMP (which uses the same base period as Hansen's original plot) the RSS data needs to be shifted up by about 0.25°C (eyeballed from the center of the trendlines in the above plot) to match the projection's temperature scale! The difference in slope of the two linear fits would result in pushing the red line in your graph even higher, but that's a smaller effect. In effect, this necessary correction pushes the red line a good grid cell upwards.

Point b) is fatal to the veracity of your plot. It also destroys the argument you are basing on your graph.

Alex, feel free to distribute this info, it's not really rocket science.

bluegrue said...

Minor correction (I shouldn't post late at night):

The slopes of the linear fits are irrelevant for the base period correction.

kostenloser Counter