1. Does (climate) science need to be consensual
to be authoritative?
Mike Hulme
Professor of Climate Change
STEPS Centre Conference, 6 February 2013
‘Credibility across cultures: expertise, uncertainty and the
global politics of scientific advice’

2. Making consensus
2
“… the peer review has helped
ensure a high degree of consensus
amongst authors and reviewers
regarding the results presented.”
[IPCC, 1990: v]
Sir John Houghton
July 1990

3. Selling consensus
3
IPCC media release, November 2007

4. Defending consensus
4
“This is the conclusion of 4,000 scientists appointed by
governments from virtually every country in the world …
Attempts by politicians in this country and others to present
what is an over-whelming global scientific consensus as little
more than an unfolding debate … are nothing short of
intellectually dishonest. They are a political attempt to subvert
what is now a longstanding scientific consensus …”
Kevin Rudd, 6
November 2009

5. The Guardian, 27 January 2007
Exploiting consensus

6. Acknowledging dissensus
6
… “Although … there is a minority of
opinions which we have not been able to
accommodate, the peer review has helped
ensure a high degree of consensus
amongst authors and reviewers regarding
the results presented.”
[IPCC, 1990: v]
Sir John Houghton
July 1990

7. Claiming authority
7
… “Although … there is a minority of
opinions which we have not been able
to accommodate, the peer review has
helped ensure a high degree of
consensus amongst authors and
reviewers regarding the results
presented. Thus the Assessment is an
authoritative statement of the views of
the international scientific community
at this time.”
[IPCC, 1990: v]
Sir John Houghton
July 1990

8. 8
“Climate skepticism is free speech.
Alternative points-of-view deserve to be
heard” (Donna Laframboise’s blog)
Challenging consensus