It is true, as the IPCC says in its defence, that the
panel presents a range of scenarios. But, as we
pointed out before, even the scenarios that give the
lowest cumulative emissions assume that incomes in
the developing countries will increase at a much
faster rate over the course of the century than they
have ever done before. Disaggregated projections
published by the IPCC say that – even in the lowestemission
scenarios – growth in poor countries will be
so fast that by the end of the century Americans will
be poorer on average than South Africans, Algerians,
Argentines, Libyans, Turks and North Koreans. Mr
Castles and Mr Henderson can hardly be alone in
finding that odd.
TUNNEL VISION
The fact that the IPCC mobilised as many as 15
authors to supply its response is interesting. The
panel’s watchword is strength in numbers (lacking
though it may be in strength at numbers). The
exercise criticised by Mr Castles and Mr Henderson
involved 53 authors, plus 89 expert reviewers and
many others besides. Can so many experts get it
wrong? The experts themselves may doubt it, but the
answer is yes. The problem is that this horde of
authorities is drawn from a narrow professional
milieu. Economic and statistical expertise is not
among their strengths. Making matters worse, the
panel’s approach lays great emphasis on peer review
of submissions. When the peers in question are
drawn from a restricted professional domain –
whereas the issues under consideration make
demands upon a wide range of professional skills –
peer review is not a way to assure the highest
standards of work by exposing research to scepticism.
It is just the opposite: a kind of intellectual restrictive
practice, which allows flawed or downright shoddy
work to acquire a standing it does not deserve.
Part of the remedy proposed by Mr Castles and Mr
Henderson in their new article is to get officials from
finance and economics ministries into the long-range
emissions-forecasting business. The Australian
Treasury is now starting to take an active interest in
IPCC-related issues, and a letter to the British
Treasury drawing attention to Castles–Henderson
(evidently it failed to notice unassisted) has just
received a positive, if long delayed, response. More
must be done, and soon. Work on a question of this
sort would sit well with Mr Henderson’s former
employer, the OECD. The organisation’s economic
policy committee – a panel of top economic officials
from national ministries – will next week install
Gregory Mankiw, head of America’s Council of
Economic Advisers, as its new chairman. If Mr
Mankiw is asking himself what new work that body
ought to take on under his leadership, he need look
no further than the dangerous economic
incompetence of the IPCC.