I have noted before that cherry-picking short-term trends in data – and scrupulously omitting mention of the same data set when the trend reverses – is a favoured tactic of polemicists attempting to argue against scientific evidence. Let’s take a look at a couple of graphs from sources Andrew Bolt was keen on not so long ago.
Exhibit A
Just last month, Andrew loved this graph:
NASA’s Aqua satellite – one of the four main measurements of world temperature – found June had dropped back to just .001 degrees above the average for the past 30 years.
That means we’re back to “normal”, even if “normal” now is slightly warmer than the average for last century, during which the planet came out of the Little Ice Age that ended 150 years ago.
Exhibit B
At the beginning of May, Bolt noted that Arctic sea ice had “risen” and suggested Four Corners would not give that trend the same coverage they gave to declining Arctic sea ice. At the time, he used this graph:
Ice extent averaged for July 2009 was the third lowest in the satellite record for the month of July. The long-term trend indicates a decline of 6.1% per decade in July ice extent since 1979, relative to the 1979 to 2000 average, an average of 62,000 square kilometers (24,000 square miles) of ice per year.
Conclusion
What do these updated graphs mean in relation to climate change? Nothing much, really – the temperature rise is likely due to the emerging El Nino phenomenon, and the annual level of Arctic sea ice is affected by weather patterns (although the long-term trend is a worrying sign).
Which is what they meant when Bolt used the earlier ones. If he was to post the current graphs, it would reveal to any sensible reader the foolishness of his reliance on these sorts of data. But instead, he’ll probably drop these data sets out of his repertoire and find some new graphs that help his agenda.
UPDATE: Bolt gives the temperature data a very quick mention – without posting the graph – at the end of this post.
7 Comments
I recently visited hospital (just overnight), and while I was there I thought of a fairly decent retort to the “too small to make a difference” graphs. It’s a bit morbid, but …
Take a graph of all the juices in your body. Then show the percentage of those which represent your blood. Then draw a square around the tiny blood-sugar component. Then shade in the amount that has to vary before unconsciousness or organ damage occur.
What’s happened to tee? He should be all over this, calling us innumerate because we believe those graphs are consistent with the AGW hypothesis.
Why don’t his regular readers see these tactics he uses, he’s pretty transparent really.
Anyway once the ETS becomes legislation in november bolt can complain about the weather all he likes, it will be meaningless because everyone else will be talking about emissions abatement strategies and debating nuclear and renewable technologies, not arguing about whether the planet is warming. That will be the ground occupied by nutty conspiracy theorists who think AGW is a leftist plot to destroy capitalism.
He has been banned from commenting.
(NB: Now that I have clarified that point, I don’t intend to have further comments directed toward someone who can’t respond.)
I mentioned the Arctic Sea Ice Extent graphs in a post on his blog and got howled down as a troll by the sheep…….
gezzam – Oh you can’t do that!
It just proves how using short period graphs as ‘proof’ of trends or in Bolt’s case to ‘disprove’ them is silly.
The interesting one about the sea ice is that they include +/- 2 std dev which represents a significant difference to the norm during the timeframe.
I’m confused by the warmists. Last year the drought was due to global warming. This year has been the wettest year in Australia since records were begun in 1904. That too is apparently due to global warming. It seems everything is due to global warming. Now even Osama bin Laden is worried about global warming. Very confusing, and difficult to argue with. Will we see suicide bombings against farting cows next?