Mark Lynas's new book The God Species contains a few pages that
dispute my account of ocean acidification in particular. Mark
kindly alerted me to this and asked for my reaction. The result was
an exchange, which Mark has put up on his blog here, which I mirror here.
I thank Mark for taking my arguments seriously and suggesting an
exchange of ideas.
Lynas: In my book The God Species I take science
writer Matt
Ridley to task for downplaying the dangers of ocean
acidification. He responded via email, and I to him. Here is the
exchange. Matt's final short responses are also included, indented
as 'Ridley2′. Square brackets are mine, for clarification.
Ridley: You say [in The God Species]: "Why not
just admit candidly that whilst the human advance has been amazing
and hugely beneficial, it has also had serious environmental
impacts?" Answer: I do. Human beings have serious environmental
impacts. I say so and I do not deny them. For example: "Take
coral reefs, which are suffering horribly from pollution, silt,
nutrient runoff and fishing - especially the harvesting of
herbivorous fishes that otherwise keep reefs clean of
algae." From megafaunal extinction to alteration of the
composition of the atmosphere, I detail lots of changes wrought by
humans. On both climate change and ocean acidification, I accept a
human alteration of the environment as real. What I argue with is
whether the negative impacts are always as great as claimed or the
positive ones always as small as claimed. That's quite different
from not admitting that there are impacts, serious and
otherwise.
Lynas: Fair enough. Everyone is of course
entitled to draw their own conclusions - hopefully based on a
reasonably non-selective reading of the available scientific
evidence - about the relative seriousness of the different
environmental challenges we face. That is actually sort of the
point of the 'planetary boundaries' exercise: to quanfify
numerically the possible limits to human alteration of different
Earth system processes, and in so doing highlight their urgency or
otherwise. From the 'planetary boundaries 1.0′ exercise which I
profile in the God Species book, the conclusion is pretty firmly
that biodiversity and climate change are top-level urgent concerns,
closely followed by the disruption of the nitrogen cycle, ocean
acidification and others. I hope you can see the value in this as a
way to ground our discussions and prioritisation efforts
somewhat.
In addition, the boundaries all interact, and not always in bad
ways - for example, our accidental spreading of large quantities of
nitrogen in terrestrial and marine ecosystems, whilst causing
problems like biodiversity loss and eutrophication, also has the
benefit of increasing carbon uptake and thereby slightly reducing
global warming. My strong contention is that we need to consider
the boundaries together (assuming they are widely accepted in
current or amended form) in any meaningful analysis of how to
manage the planet sensibly.
Ridley: Next, to your discussion of ocean
acidification. I resent the implication that I am a "denier". What
precisely am I denying? I don't deny that oceans are being made
lower in pH by human emissions. I don't deny that man-made
emissions are affecting climate; (I question the evidence for any
large effects through net positive feedbacks). And why use a word
deliberately intended to draw a parallel with the offensive lie of
holocaust denial? I don't call people like you "climate change
liars" when I think you exaggerate the probability of severe
harm.
Lynas: Again, fair enough, and although I have
used the term in the book elsewhere, I accept that the term
'denier' is problematic. In principle a person could call anyone he
or she disagrees with a 'denier'. In fact, due to my stance on
nuclear power, I have been called a 'Chernobyl death denier'. So
the charge cuts both ways. Were I writing the book now I would
perhaps be more careful about any use this term. However, although
you are free to "resent the implication" in that I discuss your
position in the context of "denialist" websites and the like, I do
not actually call you a 'denier'. In fact I talk about the
"criticism levelled by Ridley and other ocean acidification
sceptics", which is hopefully less objectionable. But please note
that I wrote this section of the book in response to your charge in
The Rational Optimist that "ocean acidification looks suspiciously
like a back-up plan by the environmental pressure groups in case
the climate fails to warm". Do you still think this is a reasonable
statement scientifically, with its implication that the undeniable
lowering of oceanic pH was dreamt up by Greenpeace?
Ridley2: of course I do not mean that
Greenpeace dreamt up the pH change, but that the predictions of
extreme damage to ecosystems likely to result from this are indeed
a convenient 'back-up plan'
Ridley: On the topic of labels, you repeatedly
call me a member of "the right". Again, on what grounds? I am not a
reactionary in the sense of not wanting social change: I make this
abundantly clear throughout my book. I am not a hierarchy lover in
the sense of trusting the central authority of the state: quite the
opposite. I am not a conservative who defends large monopolies,
public or private: I celebrate the way competition causes creative
destruction that benefits the consumer against the interest of
entrenched producers. I do not preach what the rich want to
hear - the rich want to hear the gospel of Monbiot, that
technological change is bad, that the hoi polloi should stop
clogging up airports, that expensive home-grown organic food is the
way to go, that big business and big civil service should be in
charge. So in what sense am I on the right? I am a social and
economic liberal: I believe that economic liberty leads to greater
opportunities for the poor to become less poor, which is why I am
in favour of it. Market liberalism and social liberalism go
hand in hand in my view. Rich toffs like me have self interest
in conservatism, not radical innovation.
Lynas: You are of course free to choose your
own political label, and I apologise if I misunderstood your
political allegiances. I can't however see you as a member of the
'left' in any way that I understand the term. Perhaps you are a
'market liberal' then or something? How does this position fall
then in the conventional left-right political spectrum? Once again,
I know how you feel - because in the book I have made an attempt to
cross political boundaries somewhat, and criticise much of the
green movement for entrenching itself on the far left, I am now
attacked - in John Vidal's words in last week's Observer -
as a member of a "strange new grouping" of "free market
environmentalists" supposedly allied with "US conservative
politicians". Well I never!
Ridley: Back to acid. You say that what I say
is false because acid rain was real. I never said it was not. The
acidification of rain by sulphur and nitrogen emissions is not at
issue, only the degree to which it affected forest survival and
growth rates. I made that quite clear in my Times article but you
missed it. The cataclysmic claims made in the 1980s about the
likely effect of acid rain on forest growth in Germany stand in
stark contrast to what actually happened - before any legislation
took effect.
Lynas: Sulphate pollution declined massively in
both the US and Europe due to legislation in the 1980s - cap and
trade in the US, mandatory flue desulphurisation in the EU. This
has largely solved the acid rain problem in this part of the
Northern hemisphere, although at the price of boosting global
warming somewhat by reducing the aerosol albedo in the atmosphere.
I don't think this is controversial. And it was undoubtedly due to
intergovernmental regulation - in Europe sulphur emissions began to
reduce in about 1980, when legislation really began to bite. Can't
we celebrate this as a success: rational regulation of a real
pollutant thanks to visionary policies, which solved an
environmental problem? Why play it down as if it were always a
non-issue?
Ridley2: Because it was a non-issue - in terms
of effect on forest. It's a myth that clean-air legislation had any
effect on forest health. There was not a decline in sulphur
emissions till the very end of the 1980s at the earliest, but
forest biomass was increasing throughout the 1980s.
Ridley: You accuse me of cherry-picking and
misinterpreting scientific studies. How can a peer-reviewed
meta-analysis of more than 300 peer-reviewed papers, the main paper
I cite [on ocean acidification], be a cherry-pick? And in what way
do I misinterpret it? I quote it accurately. Not one of my critics
on the ocean acidity issue has laid a glove on any scientific fact
that I cite in my book or my article. They merely blow smoke at me
by accusing me of leaving things out, or of doing things I do not.
Read my responses to them here and hereand here.
An especially good example is the matter of bicarbonate. Did you
know that bicarbonate ions increase in concentration with rising
dissolved CO2? Did you know that many corals and other calcifiers
such as coccolithophores use bicarbonate rather than carbonate as
raw material for making skeletons? I did not till I drilled into
the scientific literature and found these facts. Somehow a cursory
reading of the media had failed to transmit them. Yet three of my
critics said that while it is true that bicarbonate increases,
carbonate decreases, and then implied that I deny this. I don't,
haven't and won't. The obfuscation and distortion practised by the
critics rounded up by New Scientist on this issue did
shock me somewhat.
Lynas: The answer to your first two questions
is yes and yes. Whilst the top-line chemistry of calcium carbonate
dissolving in (or being less likely to be precipitated out of)
seawater made more acidic by the addition of carbonic acid is
intuitively rather simple, everyone also knows that this is an
over-simplification. The discussion was too technical for me to
include in the main text of my book, but I did put in an endnote
pointing out that: "Carbonic acid dissociates into bicarbonate and
hydrogen ions (protons). Most marine organisms use carbonate for
their shells, and amounts of carbonate (CO3 2-) tend to be depleted
as a result of this process." The essential chemistry is explained
in much more detail than I am competent to attempt by Feely et al,
2009 (PDF), in the journal Oceanography (vol 22, no
4). I am still not clear where you disagree, and how you manage to
conclude thereby that the ocean acidification problem is
overblown.
Ridley2: I do not accept that you are right to
say "most marine organisms…", because of recent literature showing
that many use bicarbonate as the starting point for shell
manufacture. I strongly recommend an afternoon spent
reading Hendriks et al 2010 (Estuarine, Coastal and Shelf Science 86:157 -
$) [who] found that the ion chemistry inside the bodies of
calcifiers is more important than that outside them, and there is
evidence that some of them - eg coccolithophores - actually find it
energetically easier to deposit carbonate shells at slightly lower
pH.
Ridley : You then accuse me of a 'mistake' and
an 'error' because I say "environmentalists like to call this a 30%
increase of acidity". What's the mistake? Where's the error?
Environmentalists do like to call it that. They are not wrong, and
I do not say they are wrong. It IS a 30% increase in acidity. I
merely point out that this is the most alarming way of describing
it compared with others. So you have accused me of an error and a
mistake that I have not made. This is an unattractive thing to have
done, and I would be grateful for a correction in the next printing
of your book.
Lynas: I'm afraid the error is yours, and this
should be easy to establish. You wrote in the Times piece of 4
November 2010 ('Who's afraid of acid in the ocean? Not me' - $
- this is the piece I quoted in my book) the following:
"The dissolution of carbon dioxide in the oceans may lower the
pH slightly to about 7.9 or 7.8 by the end of the century at the
worst [from the pre-industrial value of 8.2]. Environmentalists
like to call this a 30 per cent increase in acidity, because it
sounds more scary than a 0.3 point (out of 14) decrease in
alkalinity, but no matter. It is still well within the bounds of
normal variation."
This is indeed a mistake, because a 0.3 decrease in pH is not a
30 per cent increase in acidity - it is much more than that. As
Feely et al state: "These CO2 levels would result in an additional
decrease in surface water pH of 0.3 units from current conditions,
0.4 from pre-industrial, by 2100, which represents an increase in
the ocean's hydrogen ion (H+) concentration by 2.5 times relative
to the beginning of the industrial era." So if a 0.4 units decrease
in pH represents a 150 percent increase in acidity, then a 0.3
units decrease represents much more than a 30 percent increase - it
is in fact more than 100 percent. Are you now happy to admit that
you got this wrong? (Even if, ironically, it led to you
*understating* the 'scary' environmentalist case!) If I may venture
an explanation, perhaps this mistake arose because you confused the
observed 0.1 unit decrease in pH with the future prediction of
0.3/0.4 units? What we have seen so far indeed equates to about a
30 percent increase in acidity since the pre-industrial oceans
thanks to human emissions of CO2.
Ridley2: You are right and I am wrong. I did
get muddled between the 0.3 and the 0.1, just as you say. My Times
piece should have said 150%. I still find this a misleading way of
describing it, given that the entire pH range would covers many
thousands of percent, or more.
