Examination of Witnesses (Questions 130-139)
Professor Richard Lindzen
25 JANUARY 2005
Q130Chairman: Good afternoon, Professor. I gather
you have had quite a journey getting here and we are extremely
grateful to see you in good shape, if I may put it that way. Thank
you very much for coming and answering questions. We have got
a number of questions that we want to ask you, but is there anything
you want to say to start the ball rolling?
Professor Lindzen: I think the public is being
misled as to the nature of the controversy and the science. I
have given you a deposition and I will not repeat it at length,
but when your Prime Minister assured you that the bulk of scientific
opinion was on one side, in many ways I do not disagree with that.
I want to clarify that the disagreement is not over whether temperature
has been changing; almost everyone agrees somewhere around the
order of a half degree change over the last century. No-one disagrees
that carbon dioxide is a greenhouse gas and that doubling it would
increase the greenhouse effect by about 2 per cent. No-one I know
disagrees—there may be a few—that man has played a
role in the observed increase in CO2 between about 290 and 380
parts per million. Where the disagreement exists is not over that
but over whether that is an alarming statement. The reason that
is argued is, in some ways, the following. The people hear about
a doubling of carbon dioxide, let us say we start at 280 and go
to 560, we are now at 370, 380, and they think of a distant future,
maybe not so distant, probably the end of this century. When they
hear that this may account for four or five degrees or, depending
on your scenario, five-something, they do not question it, and
I think there is a very strong reason to question it. That is
to say, what is important for climate is not the level of carbon
dioxide but how much you have increased the greenhouse effect;
they are not the same. When you look at how much we have increased
the greenhouse effect since the late 19th century, it is about
three-quarters of what one would get from doubling carbon dioxide.
I explained this in my deposition so will not bother you with
it. The point with that is, if you expect four or five degrees
from a doubling of CO2, you expect almost as much, three-quarters
as much, from three-quarters of that forcing, and we have seen
only a half degree. We know that if you just kept everything constant,
doubling carbon dioxide would give you one degree of that, which
means that today we should have seen three-quarters of a degree,
which is already more than we have seen, but the models are saying
we should have seen three, which is about six times more than
we have seen. You have a choice in that, namely to say that the
models are wrong, they are overpredicting what is happening, or
saying the models are right but an unknown process has cancelled
the difference. That is where the argument lies. Are we to say
that the response today indicates low sensitivity, or we go with
an unknown process, cancelling the difference? I think that should
be understood very much. A half degree is small on several counts
and one of them has to do with a feature that I think laymen somehow
have difficulty with, namely, climate varies without any forcing.
Things like El Niño, and so on, do not have an El
Nin¯o forcer, it is just the system wobbles all of the
time, and this is true even in models, incidentally, you run them
with no forcing and they wobble. You look at a temperature records
and it oscillates and goes through all sorts of things. We do
not know what causes it and most of the time we know the system
will do it without any cause whatsoever. It means, when you are
comparing observations and what is called the null hypothesis,
the null hypothesis is would you have the agreement between observations
and a picture that just had the random internal variability? That
would consist in a horizontal temperature that was broadened to
represent the extent of the internal variability, it might be
about 0.4 or 0.5 degrees. If then you took these famous curves
of temperature, which even though they look dramatic are still
half a degree, and broaden them to indicate the uncertainty in
the observations, which is about plus or minus 0.15, 0.2 degrees,
there is no time when these two curves do not overlap, which means,
on the face of it, you do not have any reason to expect the need
for any forcing whatsoever. In engineering terms, there is a saying
we have a very poor signal to noise. I would leave it with that
as a summary of my views on the subject.
Chairman: I think you have pretty well answered the
question I was going to ask you, so I will ask Lord Marsh if he
would like to start.
Q131Lord Marsh: One of the problems, as you
know, for some of us on this Committee, is that we are not specialists
in this field at all, and listening to people like yourself it
is fascinating and produces increasing bewilderment at the level
of magnificence, so we are trying to catch up on this. To try
to get a simple question—we are on only the third meeting
of this inquiry—what sort of temperature increases, plus
or minus, by, say, 2100, do you think are at issue here?
Professor Lindzen: It depends on a lot of things.
I see no reason at present, with or without Kyoto, why carbon
dioxide will not increase. As I say in the deposition, radiative
forcing, which is the climate forcing, does not increase proportionately,
it increases ever more slowly. I do not expect to see a huge increase
in the forcing. Right now, it is close to three watts per metre
squared, do not worry about what that means. I do not see it going
to much more than four, maybe five. Even if one quadrupled CO2,
one is not talking of more than about seven or eight in that range.
The evidence so far, contrary to the models, suggests to me that
the sensitivity to four watts is of the order of a half degree,
so even with the quadrupling of CO2 I would not see more than
a degree. It is true that the models are predicting four degrees,
but the same models predict three degrees for today, and we do
not see that. In addition to that you have other pieces of evidence,
I could explain if you wanted but they are technical, they are
things that determine sensitivity, that have to do with the time
of response to perturbation, so technical issues. They point to
low sensitivity. The one thing that points to high sensitivity
is models, and these models for economists I find I have to explain.
There are in the world of models, I think, a variety of different
kinds. There are models that are "constructs" for fields
where you do not have fundamental equations, where you put in
how you think the system behaves and you use the model to see
the complicated ramifications. There are other models, like most
of the climate models, which are based nominally on physical laws,
where you do not have too much choice in the equations, you have
plenty but, the question is, can you solve them? The difficulty
with meteorology and climate models is we know the system depends
on scales ranging from metres to the radius of the earth. We do
not even anticipate a model that can encompass these spatial scales
or the timescales, we are talking about thousands of years. As
a result, the models we build do not correspond necessarily to
the underlying equations and they can produce results that differ
from the solutions, and this is particularly important for certain
things when you are transporting things, water vapour or clouds.
Clouds are the classic case. The IPCC freely acknowledges that
there is no model today that gets cloud cover within 40 per cent
of what is observed, and 40 per cent in terms of radiation represents
something an order of magnitude bigger than the effect of CO2.
Q132Lord Lamont of Lerwick: It is probably a
little unfair but I wonder if I could read you just one sentence
of the evidence we had last time from Sir John Houghton and ask
you to comment on it. "If you come to the 20th century, you
find that the increase in global average temperatures is phenomenal"
that is the word he used "compared with any variation over
the whole millennium." Could I ask you just to comment on
the validity of comparisons over a millennium and, secondly, the
use of the word "phenomenal"?
Professor Lindzen: Could I reverse that to deal
with phenomenal? You can give it any word you want, phenomenal,
unprecedented, record-breaking; it does not change the fact that
it is a half degree, we are talking about a half degree. Do not
let words befuddle you. A half degree is to be compared with the
model expectation of three. Seventeen years ago—it pains
me to think it is going on this long—when the issue started,
alarmists wanted to avoid the temperature argument, because they
were aware of that. Then they realised that the public did not
look at numbers, it was like looking at the stock reports for
the day, if the market goes up one point it looks like it goes
up a thousand points, nobody can tell the difference. Phenomenal,
I think, does not make any sense. It is small. Unprecedented is
the other thing, in the millennium. I do not even want to get
into that argument. It reminds me very much of, I do not know
if you want an anecdote but once I had a friend who went into
the Army and he came back home after basic training and was saying
he had learned something very strange. In basic training, they
were explaining to the recruits what to do if an enemy came at
you with a bayonet, and they gave them a technique so that they
could always disarm the enemy and kill them. He said he had reached
the conclusion that if his enemy has a bayonet and he has a bayonet
the first thing he should do is throw away his, because he had
a technique for defeating someone with a bayonet. We have thousands
of thermometers and we have trouble measuring the temperature
to better than a couple of tenths of a degree, averaged over the
globe. The record going back a 1,000 years is based on a couple
of handfuls of tree rings which only observe growth in the summer.
If that is good enough to tell you within tenths of a degree,
we should throw away our thermometers. The truth of the matter
is, when the people who wrote that drew their uncertainty, you
no longer could speak of "unprecedented". The statement
that it is unprecedented, by any argument at all, and plenty of
people say you cannot measure it back with any meaningful accuracy,
still it is not unprecedented, the statement has to be political.
Q133Lord Lamont of Lerwick: What about isotopes
then?
Professor Lindzen: In general, isotopes are
used delta 0-18 for much longer periods. They have very course
time resolution by this standard. They would not be too helpful
on it. They have tree rings, they have bore-holes, things like
that, there are various techniques you can use, but they are all
inferior to thermometers and yet they are talking about tenths
of a degree.
Q134Lord Macdonald of Tradeston: Just pitching
forward now rather than back. Sir John, talking to us, also asserted
that even a one degree centigrade change in average surface temperature
in a hundred years would cause all kinds of unacceptable climatic
problems. Do you agree?
Professor Lindzen: I do not. I think he differs
even with the IPCC on this. This is a problem of procedure. The
IPCC has a lot of people speaking for it. That tends to override
what the text actually says. These days, people are saying, "Yes,
2 degrees." It is always arbitrary. The thing I think you
have to remember is, here in London, or especially back in Boston
for me, or in Paris, or any other place you wish to name, the
temperature variability is far greater than it is for the global
mean. Each of us is living through fluctuations of several degrees
from year to year in the place we live. Moreover, each of us lives
through a season, lives through day/night, we are talking about
20 degrees. I find it very hard to believe that, since our agricultural
systems, our lifestyle, all encompass such large changes, some
global mean is going to swamp it.
Q135Lord Lawson of Blaby: You have been very
eloquent and it is fascinating, but are you a lone voice or is
there substantial support for your views among the scientific
community?
Professor Lindzen: I think there is no core
of the scientific community.
Q136Lord Lawson of Blaby: You must speak to
your fellow scientists from time to time?
Professor Lindzen: Yes, of course, all the time,
because some of the work is really just quite independent of one's
position on this. I think, at MIT, Chicago and other places I
deal with, even at the Laboratory for Dynamic Meteorology in Paris,
where I spend a lot of time, most people realise the issue is
a bit dodgy, but there is a problem, and you say it and it is
kind of like being a skunk at the party. In Europe, the Laboratory
for Dynamic Meteorology's climate modelling effort exists because
of global warming. At the Max-Planck Gesellschaft, their climate
modelling effort exists because of global warming. The Hadley
Centre exists because of global warming. The only place in the
world where there were efforts before global warming was the US,
but even in the US the first President Bush responded to the alarmism
with two billion dollars a year for research. I do not think you
are going to see much objection to the alarmism, but the points
of agreement, when they say that scientists all agree, it is basically
what I have written in this deposition. Scientists have learned
of what I call the iron triangle of alarmism, that they can utter
innocent statements, such as the one the Prime Minister said,
that are completely consistent with nothing much happening, so
they have not compromised their scientific integrity and yet these
will be interpreted with alarm, and the body politic, at least
in my country, will respond by feeding money to the science. Why
would anyone get in the way of that?
Q137Lord Lawson of Blaby: That I understand
very well, but the suggestion is that policy decisions, which
might be economically extremely costly, should be based on what
you call alarm. So it is not just academic corruption, in the
nicest possible way, academics being human like everybody else,
put it that way, there is more involved?
Professor Lindzen: Of course there is. I think,
and here I am not speaking as a scientist, we have reached a stage
in our country where the belief is, if the politicians want to
go along with this and are gullible enough, it is their problem.
I think there is that degree of social disintegration.
Q138Lord Lawson of Blaby: Lord Lamont mentioned
an important bit from the evidence that this Committee received
last week from Sir John Houghton. Have you seen a transcript of
his evidence?
Professor Lindzen: No, I have not, but I have
heard of it.
Q139Lord Lawson of Blaby: If you have heard
about it, is there any comment you would like to make on any of
the things you have heard?
Professor Lindzen: Yes; sure. First of all,
I heard him say that my comments are simply verbal and I have
presented nothing on it, so I have brought with me my list of
peer reviewed publications. In the last four years alone there
are 28 on the issue of feedbacks, and so on. The other thing is,
he argued, and this relates to the IPCC, that the IPCC Third Assessment
rejected the views, and this really presents a problem. I do not
know how familiar you are with the procedure, but each chapter
has a set of lead authors, of the order of 10 or a dozen. They
have a co-ordinating lead author. Each of the lead authors is
responsible for a page or two or three, together with two other
authors. In some ways, in science, this is one of the most expensive
volumes I know. I estimate, per page, in travel expenses alone,
plus missed work, it amounts to about $40,000 a page.
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