[From a UK ad campaign for DIY products]

The old man was confronted the other day by a person who wanted to debate the significance of a particular claim which had been made in a newspaper, which in turn had come from a reference to a journal paper about undersea volcanoes (you may know the one I mean) .

The trouble with discussions based on reports about papers is that, unless you can read the paper, it’s hard to know how accurate the report is. Here is an example from a current journal.

This is an abstract for a paper out yesterday in Geophysical Research Letters.

This is a copy:

Long term climate implications of 2050 emission reduction targets

Weaver et. al.

Abstract

A coupled atmosphere-ocean-carbon cycle model is used to examine the long term climate implications of various 2050 greenhouse gas emission reduction targets. All emission targets considered with less than 60% global reduction by 2050 break the 2.0°C threshold warming this century, a number that some have argued represents an upper bound on manageable climate warming. Even when emissions are stabilized at 90% below present levels at 2050, this 2.0°C threshold is eventually broken. Our results suggest that if a 2.0°C warming is to be avoided, direct CO2 capture from the air, together with subsequent sequestration, would eventually have to be introduced in addition to sustained 90% global carbon emissions reductions by 2050.

How is this paper going to be reported? ‘Carbon capture needed to avoid dangerous warming‘ might be one possible headline. This is, at first glance, what the paper has concluded. Maybe a journalist might want to go with, ‘2C warming now unavoidable‘.  Both would appear to report the content of the paper as it is presented here.

But the abstract, whilst it tells us the result of the work done on the climate models by the team, doesn’t tell us a lot of important things we might want to know before deciding what its significance is. Which model are they using? As Weaver et. al. are based in BC, Canada, are they using the Canadian climate simulation model? What equilibrium climate sensitivity has been used as a baseline in their model runs? Have they used a range of values, or the CCSM ‘standard’ value? What about the other sensitivities and the emissions pathway; do these make a difference? And how are feedbacks calculated? What about aerosol outputs?

Then there is the question of the situation under which such reductions in emissions might be made; there must be some assumptions regarding a scenario; have emissions by 2050 been reduced by new power plants, reforestation, economic recession, population stasis? Has technology been introduced by 2050 which might materially change the picture? And that figure of 2C: one presumes it refers to 2C above pre-industrial values, but it doesn’t say so. And is 2C the ‘threshold’ for ‘dangerous anthropogenic interference’? This is a relatively recent suggestion made by several teams/papers, but it is hardly conclusive, yet.

None of these questions can be addressed by looking at the abstract. Nor can the question whether atmospheric capture and sequestration is the inevitable – or even the obvious – conclusion.

Any conclusions drawn from the information then, must be seen as speculative. Unless more information is available in the paper itself, the truth value of the suggested headlines is unknown, even if key words such as ‘needed’ or ‘unavoidable’ are placed in parenthesis.

It may well turn out to be true that we are committed to a global warming of 2C above pre-industrial levels by the end of the century (it certainly seems likely), and it may be true that the only way to avoid this would involve carbon capture. But we can’t know this from the abstract, and probably not from the paper, either. So any reports about what the paper is telling us about our future which is significant are speculative, and cannot be otherwise.

What might look like a simple finding with a simple conclusion, which can readily be presented as ‘evidence’ for the necessity of technological development of carbon capture mechanisms, therefore turn out to be less simple than it first appears. The problem is, whilst any scientist might be aware of these caveats and uncertainties, a journalist might not (or might not be interested), and a member of the ‘non-scientific’ public may well not. But the message that the public will get will be decided by the journalist, not the scientists. And the journalist’s interpretation will depend on a great many things, not least of which is what his boss wants him to say about climate change, but which also is likely to include what his readers’ existing attitude to climate change is, prior to the existence of the story.

So here is an object lesson in not believing what your eyes tell you. Because, in most cases, for most scientific research, not only does it not necessarily ‘say what it does on the tin’, but half the time we don’t even know what’s in the tin. The ‘interpretation’ of the meaning of the paper is thus more likely to be about what we want it to tell us, than about what it actually does tell us.

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