Day 011 - 12 Jul 94 - Page 19
1 A. No.
2 Q. The easiest way of dealing with this is to turn to section
C in that bundle, just to get it out of the way, which is
3 the SORG report for 1990?
A. Yes.
4
Q. Page 12, I do not know how this is arranged, but mine has
5 a "12" at the bottom left-hand corner under the main
heading "Predicting Changes in atmospheric composition".
6 Have you got that, Professor Duxbury? Page 12 of section
C?
7 A. Well, in this one, yes. It is the one which has the
label little 11 at the bottom, "Predicting changes in
8 atmospheric composition".
9 Q. That is the heading. If you turn over the page, the
chapter heading is "Predicting changes in atmospheric
10 composition"?
A. Yes.
11
Q. On the right-hand side, table 2.1, do you see that?
12 A. Yes.
13 Q. These substances are called generally halocarbons, are
they?
14 A. Yes.
15 Q. In the right-hand column we see the estimated lifetime?
A. Yes.
16
Q. CFC-12 has now gone up from 111 to 120, do you see that?
17 A. Yes.
18 Q. HCFC-22 has a lifetime of roughly 15.3 years, do you see
that?
19 A. Yes.
20 Q. Which is roughly five per cent as long as -- sorry, 15.3
years. If you look at this time the ozone depleting
21 potential, which is ODP; is that right?
A. Yes.
22
Q. Under 1-D*, yes?
23 A. Yes.
24 Q. Which is just a question of where the data comes from, is
that not right?
25 A. No, the 1-D and the 2-D depend on the type of model
which has been used to do the calculation. 1-D means it
26 is a so-called one dimensional model; 2-D means it is a
two dimensional model. If you like, the difference
27 between 1-D and 2-D will give you some idea of the model
accuracy. You will notice under both models it ends up
28 with roughly the same ozone depleting potential.
29 Q. I was just going to draw your attention to that. HCFC-22
has an ODP of 0.05 in both columns?
30 A. Yes.
