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Climate Change Committee 3

A week ago I traced one of the scientific claims underlying the the Climate Change Committee's policy recommendations back to source. This was the claim that there would be 5-8% increase in dry areas in Africa.

The source was a paper by Fischer et al 2005, although the dry-areas claim could actually be traced back further.

However, I'm grateful to a reader for pointing out some interesting things about Fischer et al 2005. While it is clearly the source of the IPCC's doom-laden claim, in fact the paper appears much more rather optimistic about the effects of climate change on agriculture than might be expected. Here is what it has to say about sub-Saharan Africa:

Of particular relevance to regional food security is the case of sub-Saharan Africa, where a growing share of people considered undernourished is located. BLS baseline results indicate a significant reduction in both the absolute number and percentage (compared to world  population) of undernourished people, i.e. at risk of hunger, for all SRES scenarios by 2080,  except for A2, due to significantly larger populations and slower per capita income growth in that scenario.

Globally the authors seem to think that the impact of climate change will be small, again with the exception of the A2 scenario.

Finally, in terms of food security, AEZ–BLS results indicate significant climate change effects would occur only if levels of undernourishment were already high under ‘no climate change’ conditions, e.g. as in SRES A2.

As I said in my earlier piece about Fischer et al, the output of climate models is not robust at a regional level enough to inform policy. But what this shows is that the IPCC is actually doing something worse than placing reliance on unreliable studies. It is pointing to the black spot on an overwhelmingly white sheet and using this as the basis for the claims in its report - this does look rather like cherrypicking.

And of course, the Climate Change Committee then pick up these carefully selected findings and use them to inform UK policy.



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Reader Comments (12)

There will be drought and famine, biblical flooding, war and disease.....For it is written....

Oct 9, 2011 at 8:01 PM | Unregistered CommenterFenbeagle

Cherry picking, suppressing evidence, or the fallacy of incomplete evidence is the act of pointing to individual cases or data that seem to confirm a particular position, while ignoring a significant portion of related cases or data that may contradict that position. It is a kind of fallacy of selective attention, the most common example of which is the confirmation bias

I left ou the final bit of the quote, which is

Cherry picking may be committed unintentionally

Oct 9, 2011 at 8:05 PM | Unregistered Commenterpesadia

Brilliant FB - your best!

Oct 9, 2011 at 8:08 PM | Unregistered CommenterFoxgoose

what this shows is that the IPCC is actually doing something worse than placing reliance on unreliable studies. It is pointing to the black spot on an overwhelmingly white sheet and using this as the basis for the claims in its report

Got 'em. Well researched and reported Bish.

Oct 9, 2011 at 8:19 PM | Unregistered CommenterRichard Drake

But - all may not be lost.

The pale green horseman may yet meet his match - in Kenji the quadrapedal contrarian "concerned scientist"......

Kenji is already making waves on Guardian CIF with more comment recommends than the usual suspects for his unique scientific insights.........

Oct 9, 2011 at 8:20 PM | Unregistered CommenterFoxgoose

Like they use the hockey stick to show that current warming is not natural, but ignore that the hockey stick may be the result of a natural unmodelled negative feedback, meaning that the models are outputting excessive warming due to CO2. I heard Mann say he agrees with this and that he thinks there is a missing negative feedback'There's this reputation out there that I am some sort of climate alarmist...'.

Oct 9, 2011 at 9:07 PM | Unregistered CommenterMikeN

It is obvious that a world with higher CO2 will be warmer, will promote greater species diversity and will sustain much more life than ours does now. It's just that simple.

Oct 9, 2011 at 9:22 PM | Unregistered Commenterkim

In East Africa 95% of the natural forest has been destroyed in the last 70 years and the population has grown several fold so it is not surprising that there has been a major impact on the regional climate. Its cause is anthropogenic but has nothing to do with carbon dioxide.

Oct 9, 2011 at 9:44 PM | Unregistered CommenterSpen

It's also worth looking at how AR4 applied confidence levels to Fischer 2005. Some parts of AR4 (incl. the Synthesis Report, natch) assigned 'high confidence' to Fischer 2005's modelled projections; elsewhere they were 'highly uncertain'. (And the paper itself said they were a bit wobbly.)

Oct 10, 2011 at 8:42 PM | Unregistered CommenterVinny Burgoo

Also obvious that the sun could make me obviously wrong above.

Oct 11, 2011 at 2:58 PM | Unregistered Commenterkim

[A note to Guardian readers: our host refers here to sub-Saharan Africa as a "black spot on an overwhelmingly white sheet". Please delete all traces of this page from your browser cache.]

Oct 12, 2011 at 12:47 PM | Unregistered CommenterJane Coles

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Mar 18, 2012 at 10:44 AM | Unregistered Commenterreuiqn reuiqn

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