Examination of Witness (Questions 20 -
WEDNESDAY 15 MARCH 2000
20. That is very helpful, Sir John. Can you
help us further by just elucidating which you think are the important
areas on which there is genuine debate and variation within the
broader consensus, because those are areas which might well affect
(Sir John Houghton) I mentioned one, that is the role
of clouds, which is probably our biggest single uncertainty in
the whole business. There is the role of particles in the atmosphere,
which are also anthropogenic, many of them, they come from burning
forests, they come from sulphates emissions from power stations,
creating sulphate particles, and so on; there is a lot of uncertainty
about our knowledge of those. There is quite a lot of uncertainty
here about the influence of the ocean and possible changes in
the ocean which may occur. Rather less uncertainty aboutit
depends on the timescale you are talking about, on a hundred-year
timescale there is rather less uncertainty aboutthe ice-sheets,
on a longer timescale there is much more uncertainty about the
ice-sheets. So there are many areas of uncertainty which we argue
about and which we try to present.
21. Do you think there is any serious risk,
then, that such a level of consensus that the IPCC has arrived
at could lead to complacency on the part of governments around
the world, so that they do not react, as possibly they need to,
to guard against possible alternative explanations of climate
change; do you do anything to guard against that happening?
(Sir John Houghton) We do try, in the IPCC, to look
very hard at alternative explanations, and spend, actually, probably
more time than we should on some of them, because they get so
much publicity. We actually spend more time, for instance, on
the solar variations, about which we have very little real scientific
evidence but which some people have exploited in the media a great
deal, and we spend more time on that than probably we should,
considering how important it is scientifically. In fact, we give
more time to those things than we do to some of the more important
elements of the science I have talked about.
22. Just on this very interesting questionin
a sense, this is typical of a historical process in the development
of all branches of science, that you have a period when you have
a new subject, a new topic, and new techniques being brought to
bear, when there is debate, and so forth, and then, hopefully,
you move on to what becomes a consensus, which becomes established
science and then you can take the thing forward. How far off,
do you think, is the prospect of a sort of scientific consensus
which establishes basic knowledge in this area; or actually are
we going to have to look to a situation where the world is going
to take political decisions in conditions of continuing, as it
were, uncertainty and debate amongst scientists?
(Sir John Houghton) There always will be uncertainty
in an area as complex as climate change, partially because our
scientific knowledge is inadequate and partially because the nature
of the climate system is not entirely predictable, there is a
certain chaotic element, as it is called, chaotic being a technical
term for something that is not perfectly predictable, in the climate
system, as such, and that will always be there. So the amount
of certain information that we can give will always be limited,
and that would always be the case. But climate change is not unique
amongst science; many scientific fields, including some of those
you have already looked at, very much have the same flavour. I
think what is almost unique, perhaps, about the way in which the
climate change community has got together is that we have actually
carried out a serious, wide-ranging, completely wide-ranging,
debate in the scientific community, and attempted to put that
science forward in a coherent, understandable, accurate and balanced
form. And a great deal of effort has gone into that, the review
process, I have talked about, in the IPCC; it actually takes months
of the scientists' time, going through the review comments, which
are many times greater in volume, very often, than the document
on which they are commenting, so a great deal of effort goes into
looking at all those comments. And this is the way in which the
contrary views, of course, are properly taken into account and
23. Obviously, there are political differences
between the member countries that make up the IPCC, in particular
the States. What do you do, as IPCC, to try to resolve those differences?
(Sir John Houghton) The IPCC tries to ignore those
political differences and tries to make sure that, in IPCC meetings,
those political differences do not influence the debate. Now that,
of course, is quite difficult, because, not so much with the USA
but with the oil countries, in particular Saudi Arabia and some
of the oil-producing countries, who are strongly fed with information
by the American lobby, actually, the American coal and oil lobbyists,
they can be very difficult, in some of these meetings, because
they try very hard to weaken, or to change, or to alter, scientific
conclusions. But, so far, we have been able to, I think, successfully
resist those influences, because we stick very firmly to a presentation
of the science, not the political interpretation of that science.
24. So I guess you would say that the main political
differences, rather than being rooted in science and based on
scientific evidence, are the other way round, that there is a
very real danger of scientific evidence, in your context, being
distorted by political and commercial influence?
(Sir John Houghton) Yes, that is true, and after each
of our meetings we have had, when we have agreed policy-maker
summaries, but to agree them, by consensus, with 100 countries,
including those oil countries, is, I think, quite remarkable,
and that, actually, under a discipline of science, when you say:
"We are presenting the science, we are not presenting politics,"
it is possible to do that. There have always been some debates
after those meetings, unhappiness, perhaps, on the part of some
of the scientists, that we have bent too much in their direction
because we have had big, big debates about it. I do not think
we have bent very much at all, actually; but, nevertheless, it
has appeared to some scientists that we have appeared to do so,
that we have done so.
25. Can I come in on this? That must be very
frustrating for you, to have the US and the oil lobby, and so
on. Do you take it as part of your responsibility, not only to
collate the evidence and prepare these reports, but actually to
go to the United States, to their conferences, and perhaps even
lobby their politicians, congressmen, and so on, to do a kind
of missionary job of educating the US public, their politicians
and opinion-formers, that really they are out of line, they are
out of step?
(Sir John Houghton) Yes; many of us do try to take
opportunities in the United States to do that sort of thing. The
IPCC, of course, as an organisation, is not a lobbying organisation,
we do not take part in any political activity, we do not make
policy statements, as the IPCC; though many of us, of course,
involved in the IPCC, do go and try to explain the science, in
the best way we can, as people, as scientists.
26. Is there a part of your budget to do with
public understanding of science?
(Sir John Houghton) Yes; sure.
27. And where that public understanding is least,
for political and energy and self-interest reasons, that is where
the budget needs to be greatest, to try to persuade the politicians
there that they need to come on board?
(Sir John Houghton) Our remit, of course, is really
to do with assessment, is to publish an assessment and make that
widely available, and, by doing that, we believe we are doing
the sort of job you are describing. As an organisation, we do
not have funds for campaigning, of any kind, though some of us,
of course, do give lectures, and if we had an opportunity to go
and talk to a group of US congressmen we would take that, in order
to try to explain the science in a way that is understandable
28. Have you been able to persuade any congressmen,
senators, given your presentations to them, have they actually
changed their minds?
(Sir John Houghton) I have no evidence that any have
changed their minds. I think I have strengthened the minds of
some of those who were ready to listen, I do not think I have
succeeded in changing the minds of those who were not prepared
29. We have all met one who spectacularly refused
to listen. I am sure you know who I mean. It has been argued that,
the political differences that occur, that we have just referred
to, make it more likely that scientific opinions that challenge
the mainstream consensus have a value during the deliberations
of the IPCC. Would you agree with that?
(Sir John Houghton) Yes. Although bodies like the
Global Climate Coalition are an awful pain to us, in the way they
lobby round, and so on, and sometimes it is almost unacceptable.
Our meetings are open to observers from all non-governmental organisations,
including the industrial lobby groups, and they are very active,
of course, in our meetings, particularly the plenary meetings,
when we are trying to agree policy-maker summaries; and although
their activity is sometimes, we think, quite deplorable, but we
still have them there because it is better to have them there
than not to have them there. And, if I were asked, have they been
a good thing, in helping us produce better reports, I would say,
yes, we have produced better reports as a result of that.
30. They make you test your arguments that much
(Sir John Houghton) Because they make sure we are
absolutely honest and absolutely straight down the line, yes.
31. Just a question, or an informal observation,
on this point about your lobbying role. Really, your motto is
the motto of my old universitygreat is the truth and it
(Sir John Houghton) Yes.
32. There are strong connections between the
IPCC and the Hadley Centre, and they are both major contributors
to government advice. Do you not think that is a kind of weakness,
in a way, and perhaps the Government should extend its network
out and get more independent advice from separate university researchers,
(Sir John Houghton) The Government does, actually.
The link between the IPCC and the Hadley Centre, I suppose, is
quite strong, because the IPCC unit is housed in the same building;
but the work of that IPCC unit is not primarily scientific, the
work of the IPCC unit is organisational, it is getting the scientists
worldwide involved in this process.
33. But your advice to government often looks
very much the same, the language is different but the advice is
similar, is it not? You have not had a real argument with them
about anything yet, have you?
(Sir John Houghton) There are arguments with the Hadley
Centre about various
34. But in public?
(Sir John Houghton) Not public arguments, no. I think
a lot of members of the Hadley Centre do play a part in the IPCC
assessment, because they are one of the leading places in the
world where you find scientists of this kind; it probably involves
a wide range of university people, too.
35. Does the Government go independently to
these other organisations besides you and the Hadley Centre?
(Sir John Houghton) Yes, it does, actually. For instance,
the University of East Anglia is well represented in government
36. Do they ever have contradictory advice to
government, that you know of?
(Sir John Houghton) Their emphasis sometimes is quite
different, and we have argued about certain things. I will not
go into those details now, but there have been arguments between
us, as you can imagine.
37. So you do not think there is a cosiness
that makes you vulnerable to outside attack from green groups,
as, for example, English Nature felt with the GMO debate?
(Sir John Houghton) That danger is always there, of
course, if there are people who are working too closely together,
and that danger must be watched; and government must go to a wide
range of people to get its advice, to make sure that that cosiness
is not a problem, I would agree with that.
38. Sir John, your memorandum states that "the
variety of factors influencing climate change is well understood
by government". What evidence do you have that the reports
and assessments produced by the IPCC have been understood and
have been absorbed by the key policy-makers that you are addressing?
(Sir John Houghton) I think, if you take meetings,
for instance, of the Framework Convention on Climate Change, those
international meetings of politicians which are addressing the
climate change issue, they are making a lot of use of IPCC material,
in fact, they use it a great deal, and I think it has educated
them very much in the science of climate change, and, indeed,
in the possible impacts and the policy responses from the other
IPCC working groups. So it has been a very influential body, in
39. Is not there a risk that people are uncomfortable
with the uncertainties that you have been speaking of, and the
brackets and tolerances, and come down on a particular number
and a particular interpretation without taking into account some
of what are probably your reservations?
(Sir John Houghton) Our assessments do not give you
one given number, they give you a range of numbers, in all cases,
actually; they do not come down on particular answers to the problem,
they give you a range of answers to the problem.