Examination of Witnesses (Questions 80-85)
Dr Chris Hope
18 JANUARY 2005
Q80Lord Macdonald of Tradeston: And are such
models being worked on?
Dr Hope: Yes, at all levels of detail from the
rather simple functions of integrated assessment models like PAGE
to much more detailed models which try and look at the whole of
the energy economy and optimise that under different conditions.
That side of the problem is being worked on probably with at least
as much effort as is being put into trying to make estimates of
damage.
Q81Chairman: Sir John said that there were about
25 models. Do you confirm that that figure is about right?
Dr Hope: He was probably talking about the very
large scientific models, the general circulation models. The integrated
assessment model is a slightly different beast but I would say
there are probably about 20 of those as well.
Q82Chairman: Does the IPCC rely upon some models
rather than others? What do they use?
Dr Hope: They try, when looking at integrated
assessment models, to take the same kind of approach as they do
with the scientific and economic information they get, which is
to invite in as many people as they can who have something sensible
to say. The schools of modelling tend to be a group of people
in the United States with Bill Nordhaus and Hadi Dowlatabadi,
who build these kinds of models, which tend to be more of the
optimising models, in the United States. There is a school of
modelling which occurs in Europe—Richard Tol in Hamburg,
there is the PAGE model here in the UK, and there are models that
come out of Japan. All of those have been incorporated into the
IPCC.
Q83Lord Sheldon: The basic problem seems to
be that of population and damage to population. I imagine that
is by far the largest important element that you take into account
and have to account for. Which are the biggest population problems
that you have seen? We know that Bangladesh is an obvious one.
What are the others? Can you give us some indication? Indonesia
is one. What are the other ones that worry you most?
Dr Hope: It certainly looks as though over probably
the next 50-100 years the major impacts of climate change, the
most severe ones, will be likely to be from sea level rise. Sea
levels rise because the oceans expand and also because you maybe
get a melting of ice which leads to sea level rise. We might be
talking about a sea level rise of a metre or so. Therefore, the
most vulnerable populations are likely to be the ones that are
in the low-lying areas and that is why Bangladesh is particularly
vulnerable. The other populations that are likely to be at risk
are in areas where you are already at the margin of liveability.
The temperature is so hot and the air is so dry that it is almost
impossible to live there and grow crops or have livestock. Those
areas are the ones that are likely to be hit if the temperature
rises by two to five degrees and if the rainfall patterns are
altered. That would be African populations typically. In the integrated
assessment models, when you look at the different regions, by
far the biggest impacts (both in absolute terms and also as a
percentage of GDP) occur in Asia, in Africa and Latin America
tends to be the third. The impacts in the developed world often
are under one per cent of GDP by 2100. The impacts in Asia could
be well over 10 per cent of GDP and maybe up to 20 per cent of
GDP or more if we do not take some serious steps to cut back the
emissions and therefore lower climate change.
Q84Lord Sheldon: You mentioned Latin America
which rather surprised me.
Dr Hope: Yes, areas of Latin America typically
that are the border areas where people are trying to live on the
margins. They are the ones that would tend to be affected, mainly
because the adaptive capacity is lower there. You can assume that
in developed countries, such as Europe and North America and other
parts of the OECD, if we were to have, say, two or three degrees
centigrade temperature rise, we would be able to adapt to it fairly
well, but that scale of temperature rise would be almost impossible
to adapt to in Asia, in Africa and in parts of Latin America.
Q85Lord Sheldon: What parts of Latin America
are you thinking of?
Dr Hope: It tends to be areas of Brazil and
Central America, areas which are already on the margins of liveability,
and vunreable to extreme climate events.
Chairman: Thank you very much indeed.
We are most grateful to you for coming along and answering our
questions. We have all learned a lot from it.
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