The IPCC assessments 221community to the understanding of global climate change and to the
communication of the best scientific information to the world’s politi-
cians and policymakers. After all, the problem of global environmental
change is one of the largest problems facing the world scientific com-
munity. No previous scientific assessments on this or any other subject
have involved so many scientists so widely distributed both as regards
their countries and their scientific disciplines. The IPCC Reports can
therefore be considered as authoritative statements of the contemporary
views of the international scientific community.
A further important strength of the IPCC is that, because it is an inter-
governmental body, governments are involved in its work. In particular,
government representatives assist in making sure that the presentation
of the science is both clear and relevant from the point of view of the
policymaker. Having been part of the process, the resulting assessments
are in a real sense owned by governments as well as by scientists – an
important factor when it comes to policy negotiations.
In the presentation of the IPCC assessments to politicians and pol-
icymakers, thedegree of scientific consensus achieved has been of great
importance in persuading them to take seriously the problem of global
warming and its impact. In the run-up to the United Nations Conference
on Environment and Development (UNCED) at Rio deJaneiro in June
1992, the fact that they accepted the reality of the problem led to the
formulation of the Climate Convention. It has often been commented
that without the clear message that came from the world’s scientists,
orchestrated by the IPCC, the world’s leaders would never have agreed
to sign the Climate Convention.
Since the publication of the reports, the debate concerning the scien-
tific findings has continued in the world’s press. Many have commented
favourably on their clarity and accuracy. A few scientists have criticised
because they feel the reports have insufficiently emphasised the uncer-
tainties; others have expressed their disappointment that they have not
spelt out the potential dangers to the world more forcefully. The scientific
debate continuesas indeed it must; argument and debate are intrinsic to
the scientific process.
I have illustrated the work of the IPCC by describing in some detail
the activity of the Science Assessment Working Group. The IPCC has
two other Working Groups that have followed similar procedures and
have dealt with the Impacts of Climate Change, with Adaptation and
Mitigation strategies and with the Economics and Social Dimensions of
Climate Change. Contributions to their work have not only come from
natural scientists; increasingly social scientists, especially economists,
have become involved. In these social science areas much fresh ground
has been broken as consideration has been given to questions of what,