Forum

Climate science: why the uncertainty?

I note the raft of letters in the last magazine on anthropogenic climate change (ACC). While I, on the committee, am perfectly happy with the position statement and scientific consensus. (ie, Mankind is generating large quantities of CO2, - this entraps solar radiation and causes temperature to increase) I don't understand the massive spread and uncertantity of this increase: 1 to 5 degrees. Hundreds of percent? In fact you can easily find other scientists that say 0.7 to 8 degrees, and even a couple more that claim these figures are half what they should be! They all claim they have good data. Who to believe? Can't climate science please do a little better?

Lets compare it with quantum electrodynamics (like ACC, not a trivial science). Just a few years after Chadwick discovered the neutron, Paul Dirac predicted the magnetic strength of the electron to within 0.007 percent of its modern value. Maxwell's electromagnetic equations were developed in the 1860s after three years of hard work (sans PC or 'app' - gasp!) and are as precise today as in 1865, and are as precise to as many digits as one can afford to buy. Einstein predicted how tiny changes in gravity will alter time, and it took 43 years for atomic clock technology to develop to prove his theory within one percent.

I have also seen, in this debate, a common enough trick by pundits. It's a special technique called 'unit-hopping'. Some will quote in tonnes of carbon, some in tonnes of CO2 (they are not the same!). Some use ppm, some a percentage, and so on. This seems cunningly designed to confuse and confound everybody from newcomer to veteran. Just when things are starting to make sense, the pundit quickly hops to a new unit, so it's hard to follow the line of reasoning.

And obsfucation is a common enough trick. For instance, our WWF claims that if we all had one car-less day each week, changed to CFL/LED lighting and turned off un-needed appliances, we would "have a big impact". Well, they throw about some very large numbers indeed (quite correct ones to be fair, but almost certainly designed to impress the statistically-challenged) but then omit to state their figures work out to about a one percent saving. Well, to me, one percent is not, and never will, be "big". I do all those things, and much more, but still consider my contribution minuscule compared with the 'elephants in the corner of the room'.

So why all the name-calling, angst and vitriol? Well, the uncertainty , the unit-hopping, and the plethora of experts leading to confusion and doubt about their error budgets hardly help. But I also believe a partial answer lies in the cognitive dissonance between the desire to talk about it, and the unpleasant shock of having to actually do something (more simply: lots of hui but little dui). I see one answer in the excellent book Heat by George Monbiot (No 1 arch-enemy of ACC deniers). He points out the changes the world needs to make are possible, but only just, and with consequential dramatic lifestyle changes, but it's political suicide for any government to order this.

The comment at the top of the right hand column on page six of NZ Skeptic 111 illustrates this quite well: "… a social scientist stood up and said that we were all wrong because the real question is how society actually responds to major issues. There was a bit of a stunned silence and the chairman changed the subject". What a party pooper!

Given that we generate about .087 percent of the world's emissions, and that about half our emissions come from farming, mainly dairy, we can only make a large impression (mainly on ourselves) by eliminating farming, especially dairy. So yes, let's do it, that'll show the rest of the world! But this is akin to me worrying about the last two incandescent bulbs in my house: do I need to spend $10-$40 on CFL/LED replacements for lights that spend about one minute per week on? Then I drive about the city, and even after midnight, the place is lit up like an Xmas tree. Worry about saving energy and our carbon hoof-print? Yeah right! The happy-talk and hand-waving is a little overwhelming.

And the committee certainly knows my views on this, but I find the most appalling hypocrisy of all is that of the darling of parts of the climate change industry, one Al Gore, who used some 220,000 kW/hours of power in a year. I use around 6,300 pa. His excuse? That he works from home. Well, sunshine, so do I!

Lastly, I agree that Gold's phrase re "the sack" is wrong. Don't get me wrong, O'Briain is an incredibly funny stand-up, and a favourite of mine, and it does not offend me personally (after umpteen years in the military, I can be as abrasive and foul-mouthed as any drill-sergeant) but it's just plain unnecessary, in my opinion.

Anyway enough from me, I'm off to rustle some cows and then the abbatoir!

Barry Lennox

Rangiora

'Anti-catastrophic principle' is not Pascal's wager

In the Winter 2014 NZ Skeptic Hans Laven states that engaging in actions to combat climate change now, despite uncertainties, because of the expected outcome is equivalent to Pascal's Wager and thus fallacious. However the writer appears to have misunderstood why Pascal's Wager is fallacious. Pascal's Wager is in fact a valid argument (one whose conclusion necessarily follows from its premises). If P is the probability of God existing then the expected benefit of believing in God is P=∞ + (1-P)×f = ∞ whereas the expected benefit of not believing in God is P=(-∞) + (1-P)=g = -∞ (where f and g represent the finite loss). Believing in God obviously has the better pay-off and given the description of the problem this is the correct result. The reason Pascal's Wager is fallacious is because it is not sound (the premises aren't true). The options are not 'believe in God' or 'not believe in God' but rather 'believe in X' where X is no-god or any of a number of gods. Additionally in many cases the belief in one god precludes the belief in others so it is no longer a binary choice. With climate change on the other hand the situation is completely characterised by it either happening or not and so the 'Anti-catastrophic principle' in this case is not fallacious.

Dr Josh Voorkamp

Dunedin

Skeptics should support consensus

I am concerned at the disproportionate number of letters denying Anthropogenic Climate Change in issue #112.

Climate Change Scientists are the primary authority on the subject of climate change and the scientific consensus supports humans causing the current escalation of climate change on Earth.

Not one of your recent correspondents was a climate change scientist and any arguments made were based on the views of a tiny minority of the scientific community.

A Skeptic would take into account this disparity, and agree with the current scientific consensus, until the experts determine otherwise.

There are no Climate Change Skeptics, only deniers of the current scientific consensus.

Matt Beavan

Wairarapa