Where's the proof?
Take a look at this graph (click to enlarge):
Have a good look – it’s usually only shown for a few seconds on TV. (The bars are mine.)
This is the controversial ‘hockey-stick graph’ developed by Michael Mann, shown in Al Gore's Inconvenient Truth, and held up as proof of C02 induced temperature rises in mainstream TV documentaries and reports.
…and by extension, man-made climate change.
Scientists dispute the conclusions inferred from this graph. Whilst I’m no scientist, fortunately, it only requires the gift of sight to see why.
I’ve highlighted (in bars) the easier-to-see areas of the graph that illustrate one of the broad objections of the so-called “sceptic” scientists. Note: the selections are mine, and may or may not match the same used by scientists.
A B C
The three bars marked A, B and C (shown magnified) show periods where temperature increased just ahead of C02 in the atmosphere. There are other areas of the graph where the upward trends overlap, and so are not so clear. If the graph were stretched we’d see clearer separation, one way or the other. “Sceptic” scientists will show higher resolutions which clearly show, again, that temperature rises preceded C02 increases.
D
The bar marked D is interesting because it shows C02 levels above the peak in temperature. Surely positive feedback cycles would have driven temperatures up further still? Of course, we don’t know – or at least I don’t know – what happened around that time to cause this anomaly; but interesting nonetheless.
E
The E bar is the period which elicits most alarm. But there’s a massive divergence between the temperature trend (which is soaring) and the C02 line, which hovers around 250ppm (parts per million).
You can see from the past that C02 levels have peaked way above 250ppm before.
Dig deeper into this subject and you’ll find further disputing claims. It should be noted that we’ve only been measuring this for about 160 years, mainly in the Northern Hemisphere, using equipment that has evolved and become more sensitive (and numerous) over time – maybe this explains the greater observed temperature increases of late?
One thing does appear to stand out quite clearly, though, and that is C02 levels do seem to fall before temperatures do.
Professor Bob Carter, Climate Change - Is CO2 the cause?
PS… the graph was a screengrab from the BEEB, in case you thought I was using a “sceptic” one.
Tags: climate-change
