Wednesday, September 25, 2013

Matt Ridley couldn't support his ridiculous claims

Sou | 4:37 PM Go to the first of 10 comments. Add a comment
Update - see below

Matt Ridley, unsurprisingly, can't get a word in at Slate.  So he's had to lower his sights (again) and turn to a fake sceptic, Anthony Watts and his science-denying blog, wattsupwiththat (archived here). WUWT is much less discriminating about what it publishes :(

Here is what Matt claims:
The argument I made was that climate change has benefits as well as costs and that the benefits are likely to be greater than the costs until almost the end of the current century.
Matt's persisting in his false claim that global warming will have net benefits until 'almost' 2100, by which time he'll be long gone so I guess he doesn't care what happens to the world after that.  His main argument seems to be that "CO2 is plant food".  It's clear he's not a very good farmer.  As CO2 increases and the world heats up, it will increasingly be extreme heat, flash floods, lack of water and greater spread of plant pests and diseases that limit plant growth and agricultural productivity.  These are the result of global warming brought on by our CO2 emissions.

Matt says: Stop the World at 2 Degrees?

Logic shows that Matt's argument assumes once global temperatures rise two degrees the world will be able to stop it rising any higher.  But he also argues against any action to limit the rise.  He doesn't say whether he's arguing that the world keep burning fossil fuels till temperatures hit two degrees above pre-industrial temperatures and then all human activity needs to be stopped.  But that's where his argument leads us. The world would have to come to a standstill.

His own articles don't support Matt Ridley's claim

Matt says that he's managed to dig up two articles that support his claim. He hasn't.  He stretched way back to 2004 for one of them.  Way back before the Stern review, way back before the 2008 WGII report.

Matt's first 2004 article doesn't support his claim of net benefits.  It found that the net costs of a higher temperature increase (above 3-4 degrees) were definitely higher than any benefits.  It also found that the overall net cost/benefits up to 3 degrees wasn't clear and that more work was needed.  The paper does not claim that global warming is a net benefit.  More work was indeed done and it shows that the cost is of global warming is high and increasing.

Matt also cited a recent paper by Richard Tol.  I don't know what Richard Tol's work showed in regard to Matt's supposed "net benefits".  It is paywalled.  In the abstract Richard does say that carbon dioxide emissions are a negative externality (which even Matt Ridley shouldn't dispute). However I don't see any sign that Richard's paper says what Matt claims - that global warming is a net benefit.  Nor would I expect to. Richard has written many papers on related topics and I'm not aware of him ever coming up with the finding that rising atmospheric CO2 will do more good than harm - at any level of global warming.


In the comments, Richard Tol states that Matt Ridley "correctly cites my work".  Matt Ridley wrote:
I’d like to direct him to this 2004 survey of many studies, and this 2013 study, which confirm that climate change of 1 or 2 degrees Celsius will probably, in aggregate, do net economic and humanitarian good to mankind. It will do so by lengthening northern growing seasons, reducing winter deaths (which greatly exceed summer deaths even in countries with hot summers) and increasing precipitation, but without raising sea levels sufficiently to do serious harm.
In Richard Tol's 2013 paper, there is no mention of any of the words "humanitarian", "growing season", "rain" or "precipitation" or "summer" or "sea level".  The only mention of death was this:
Arbitrarily stringent climate policy would be a disaster: Billions of people would starve to death.
Unlike Matt Ridley's article, the Tol paper does mention the unequal impact of global warming but from an economic perspective, stating for example:
Fourth, not shown in Figure 1, poorer countries tend to be more vulnerable to climate change. Poorer countries have a large share of their economic activity in sectors, such as agriculture, that are directly exposed to the weather. Poorer countries tend to be in hotter places, and thus closer to their biophysical limits and with fewer technical and behavioral analogues. Poorer countries also tend to be worse at adaptation, lacking resources and capacity (Yohe and Tol 2002). 
The only aspect in which Matt Ridley is correct as far as I can see, is where he writes that the Tol paper indicates that  "climate change of 1 or 2 degrees Celsius will probably, in aggregate, do net economic and humanitarian good to mankind".  That's if I take Richard Tol's Figure 1 as indicative.

And that finding of Tol's I would dispute on the grounds that it must not take sufficient account of the short, and particularly not the medium and long term changes caused by global warming.  Not specific enough?  Maybe.  But I'm not the only one to dispute his findings.  Bob Ward does as well, in this article.

In fairness to Richard Tol, his Figure 1 has huge error margins and his lower bound crosses over to the negative at 0.5 degrees warming.  

It will be interesting to read what WG2 of the IPCC report comes up with when it comes out next year.

Added by Sou 8:47 pm AEDST Sat 2 November 2013.

Maybe my last sentence suggested prophecy - or just some knowledge of agriculture (see here). (Added 3 Nov 2013)

While Matt Ridley is trying to convince everyone that lurching into a hot world will be "good" for them, the rest of the world is looking for a better handle on just how big a price we are going to pay for global warming.

The cost of doing nothing is much higher

Business and political leaders around the world don't agree with Matt's contrarian nonsense.  For example, from Bloomberg this week (my bold italics):
Former Mexican President Felipe Calderon is spearheading a study sponsored by seven countries into the economics of climate change, seeking to elucidate the financial benefits of reducing carbon emissions.
Calderon’s panel will draw from the experiences of companies and governments around the world in fighting off the ravages of storms and droughts, and in cutting greenhouse gases. It also will use academic research to show the costs and risks associated with climate change and efforts to stem it, publishing a report next September to guide policy makers.
“We’ve talked about emissions -- this time, we will try to talk about profits, and that will change the equation,” Calderon said today at an event announcing the Global Commission on the Economy and Climate in New York. “The idea is that we can present an economic case. What we’re expecting is that our report cannot be ignored in 2014.”
The effort by a group that includes Unilever NV Chief Executive Officer Paul Polman and the former leaders of Chile, New Zealand and Mozambique is designed to guide global envoys as they devise a new treaty to fight climate change in 2015. Britain, Colombia, Ethiopia, Indonesia, South Korea, Norway and Sweden are sponsoring the panel.
“The alternative of not doing anything is not actually an alternative,” Norway’s Prime Minister Jens Stoltenberg said at the event. “The costs of not doing anything are much higher.”
The panel also includes business leaders such as Vattenfall AB Chief Financial Officer Ingrid Bonde, China International Capital Corp. CEO Zhu Levin and officials from the World Bank and International Monetary Fund.

Most of the above nations can't be described as aggressive when it comes to mitigation.  If they are worried then everyone else should be very worried.

And in the same week, from the UK Guardian:
It would be "absurd" to claim the risks of climate change are small, economic expert Lord Stern said before the publication of a key scientific report on global warming.
The latest international assessment of climate science makes it crystal clear the risks are "immense", and it would be extraordinary and unscientific to ignore the evidence and argue for a delay in addressing the problem, he said.
The former World Bank chief economist and author of the key 2006 Stern review on the economics of climate change also warned that scientific projections and economic predictions were underestimating the risks of global warming.

Here is a link to the 2008 WGII IPCC section discussing cost implications of global warming.  The next report is due in March/April next year.

It's no wonder that Matt Ridley has to turn to an anti-science blogger to get his silly article published.  His "arguments" are baseless.  He didn't cite a single article supporting his ridiculous claim of "net benefits".  The closest he got was a paper from nine years ago that said costs unequivocally outweigh benefits as warming progresses beyond 3-4 degrees, which is what would be guaranteed if people listened to Matt Ridley, and didn't quantify the net impact below that.

Matt Ridley ignores the range of sensitivity and makes wrong projections

Matt finishes with this, which further undermines his argument:
...if you consult the probability density functions of most recent studies of climate sensitivity, conducted by senior IPCC-affiliated scientists, you will find that there is a significantly higher than 50-50 probability of warming of less than 2 degrees Celsius during the next 70 years.
He fails to cite any "recent studies of climate sensitivity" or how they relate to how quickly the world will heat up.  There are a number of studies that suggest a low climate sensitivity of around 1.9 degrees.  There are as many if not more studies that suggest a higher climate sensitivity.  The current IPCC WG1 report states that it is likely that that the upper bound is 4.5 degrees for a doubling of CO2 - but that "values substantially higher than 4.5°C cannot be excluded".

So Matt misrepresents the risk of higher climate sensitivity by ignoring it.  Now for his assertion of "70 years".  He doesn't give any indication of how he arrived at that figure. It hinges on how long it will take for CO2 to double.   Even using low estimates of climate sensitivity, a doubling of CO2 would raise surface temperatures by about two degrees.

Because Matt urges no action to limit carbon emissions the "business as usual" scenario is likely to be conservative.  Atmospheric CO2 might not just double (to 560 ppm), it could be triple or go even higher before the end of this century.  At that point global warming will not suddenly stop unless the world comes to a complete standstill.

From the WUWT comments

Dr Burns says Matt Ridley is not a good scientist, but for different reasons!
September 24, 2013 at 4:56 pm
A good scientist would consider the potential effects of global cooling. A major Ice Age is inevitable in the not too distant future.


  1. Another problem for agriculture is that much of our food is grown on land within 5 feet of sea level, particularly on the great river deltas which are home to hundreds of millions of people - Nile, Ganges, Bramaputra, Mekong etc - and rising sea levels will make the soil more saline and then drown it. Cereal doesn't grow very well in sea water!

  2. Just had quick look at the 2004 study (Hitz, S. and Smith, J. Estimating global impacts from climate change. Global Environmental Change 14 (2004) 201–218) Mr Ridley cites. It’s a rather long paper so I will quote the basic conclusion from the Conclusions and discussion.

    “That said, one consistent pattern is that by an approximate 3–4oC increase in global mean temperature, all of the studies we examined, with the possible exception of those on forestry, suggest adverse impacts. It appears likely that as temperatures exceed this range, impacts in the vast majority of sectors will become increasingly adverse. Although many studies point to substantive impacts below this temperature level, there is no consistency; in some cases they are negative and in others positive.”

    At one point in his WUWT post Mr Ridley writes “Please note that the papers cited in the 2004 paper I mention also discuss how such mild warming will raise biodiversity, ecosystem productivity and net primary production, so the net benefits are ecological as well as economic.”

    However, unless I’m missing something from the primary literature, I don’t see any mention of effects at the 1-2oC change Mr Ridley is talking about in terms of biodiversity. In fact the section on Terrestrial biodiversity in Hitz and Smith ends with “We are highly confident that biodiversity will decrease with increasing temperatures; what is uncertain is whether the relationship between higher GMT and loss of biodiversity is linear or exponential.” (GMT, global mean temperature)

    As you note, not exactly stellar support for Mr Ridley. You have to wonder if he knows the meaning of the word adverse.

    1. Since we've already experienced some 'mild warming' no doubt Ridley can point to the consequent increase in biodiversity...LOL.

      All we can say over the last century is that we have become better equipped to begin to measure biodiversity, whatever the direction it is headed...and that we have unequivocally diminished and fragmented natural habitat, have unequivocally reduced many population numbers, while creating a few new impoverished niches and unwittingly favoring some species in the process. So whatever effect warming [or cooling] has is well submerged in losses associated with human modification of the environment.

      Ridley is not even beginning to engage with reality if he is claiming net ecological benefits.

  3. This seems to refute Ridley's arguments and emphasize that something needs to be done now:


  4. Matt Ridley correctly cites my work.

    1. Richard - so you're saying that your work shows that:

      "2 degrees Celsius will probably, in aggregate, do net economic and humanitarian good to mankind"?

      Really? If that's the case I'd like to see your work subjected to scrutiny.

      And no comment on all the "wrongs" in Matt's article, Richard? Although Matt suggests it, I find it hard to believe that your paper states that a rise of two degrees will happen: "without raising sea levels sufficiently to do serious harm."

      If it does, you are likely very, very wrong.

      The GWPF should be very proud of you appearing to defend Matt Ridley's nonsense while not really doing so. It must be getting very difficult to straddle the disinformation from the GWPF and people like Matt Ridley on the one hand, while attempting to maintain academic integrity on the other.

    2. Seems to me Richard's comment here was as much about correcting your factual error as it was about defending Ridley. Try being a little gratious and admit you wrongly accused Ridley of misrepresentation. Won't happen though, will it ? More likely that you will somehow try to blame Anthony Watts for your cock-up.

  5. It is one thing to make a mistake. It is quite another to let a known mistake stand.

    1. Oh my! This from the person who spent weeks tweeting and posting stuff all over the internet, trying in vain to dispute Cook13, and still hasn't admitted he was utterly and completely wrong!

      I still have to read your paper, Richard. It's not been my top priority and I've been quite busy this week.

      If Ridley wasn't wrong about your paper, then it's probably fair to say that you were wrong in your paper. I'll add a comment once I've determined which it was.

    2. So you will correct your paper? It contains a mistake, as you have now been made aware of.



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