I watched BBC FOUR's Climate Change by Numbers programme the other day with my usual foreboding about what the BBC's science programmes often default to: talking heads in exotic locations, with triple air miles and fine hotels for all concerned. I feared yet more trips to volcanoes, icebergs, glaciers, deserts, forests and coral islands, all of which BeeB executives are well practised at. It turned out ok, though, at least in those terms. And it was a programme that would not have been better on the radio, as BBC TV's science programmes often seem as if they would these days.
Perhaps all this was because it was presented by three mathematicians, and was all about numbers, rather than 'science'. Cue, lots of graphs, with super-fine graphics used to display data and trends. Not even Brian Cox could have managed that on the radio.
It was about 3 numbers in particular: 0.85 95 1,000,000,000,000
0.85 is the increase in temperature of the atmosphere since around 1880 – in degrees C
95 is the % certainty of the IPPC that over half this warming is due to human activity
1,000,000,000,000 is the amount of carbon we can burn (says the IPCC) and still be 66% sure that warming will remain under 2 degrees C.
The programme was particularly good at exploring how statistical processes developed in one field (eg, motor racing / the cotton industry / gold mining) were being used to crunch numbers relating to climate change. 'Crunch' is a nice term here, and it could be that those of a skeptical turn of mind might have preferred 'manipulated' or even 'fiddled' as numbers disappeared and new ones appeared in Kalman filtering, kriging, attribution studies, and use of extreme value theory.
Not that I followed all of this.
Given that we've already burnt 500,000,000,000 tonnes of carbon – that is, about half of what the IPCC says we can, and the warming is already at 0.85 degrees, this does not bode well for our being able to stop bad habits in time – as I noted the other day. Never mind. The programme was informative.
I was disappointed about one thing. The 0.85 degrees figure has an uncertainty value attached to it, but no one mentioned this. According to the IPCC this is a whopping 0.2 degrees:
"The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C, over the period 1880 to 2012, when multiple independently produced datasets exist."
That's ± 25% to you and me, which means we could be even deeper in the manure than we think, or breathing more easily. No wonder this is hard to teach about.
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