Day 011 - 12 Jul 94 - Page 52
1 After that, once the chlorofluorocarbons have got into the
upper part of the stratosphere and have been broken apart
2 by ultraviolet light from the sun, then it is the current
chemical model assumes that the chlorine, once it has
3 reached that stage, is held in two types of chemicals,
so-called reservoir species (of which the two principal
4 ones are hydrogen chloride and chlorine nitrate) and the
destructive species (which is chlorine monoxide) and,
5 therefore, the atmospheric measurements attempt to measure
both the concentrations of reactive chlorine of which
6 chlorine monoxide is taken to be an example, and the
inactive but possibly liberatable chlorine, of which
7 hydrogen chloride and chlorine nitrate are taken to be
examples.
8
So that until either hydrogen chloride or chlorine nitrate
9 have been removed from the stratosphere, they form part of
a pool of the so called chlorine loading in the
10 stratosphere. In other words, the chlorine loading is the
amount of chlorine which is primarily in the source
11 molecules and the reservoir species and the reactive
species.
12
MISS STEEL: What do you consider the overall effects of HCFCs
13 to be now?
A. If I take the government reports and paraphrase those,
14 they are considered to be very much the minor contributor
to the ozone, current ozone depletion. The main
15 contributor is the residual CFCs in the tropisphere which
have not yet made it into the stratosphere together with
16 the use of CFCs and, in fact, carbon tetrachloride in
other countries which have not so far got the technology
17 to, in fact, control them. But if you actually look at
the evidence about the use of these by the McDonald group,
18 then in fact the McDonald group are not using any of the
CFCs any more and their HCFC use is at a very low level.
19
Q. Just while we are on that small point, where did you get
20 your figures from for McDonald's usage?
A. I got the figures for McDonald's usage from the paper
21 work provided by either Perseco or, in fact, by the UK
suppliers of blowing agents to McDonald's who, in fact,
22 quoted the Stratospheric Ozone Review Group documents as a
reason for why in the United Kingdom McDonald's should no
23 longer use HCFCs.
24 Q. Right, so they were basically from McDonald's?
A. Yes.
25
Q. Or their suppliers?
26 A. Yes, but the global -----
27 MR. RAMPTON: My Lord, I have to say -- may I intervene; I am
sorry -- as I indicated this morning, I think the witness
28 has information or some paper which I do not have and
which I think the defendants probably do not have.
29
MR. JUSTICE BELL: What is it which you have got this from,
30 Professor Duxbury?
A. The information I got was from, basically, all the
