Chairman's Introduction

John Houghton is a well qualified person to give this lecture: as some of you will know, he has been deeply involved in the debate over climate warming for some time, has a strong academic background in the area, was lecturer, reader and professor in atmospheric sciences in Oxford, then was Director General of the Met Office and as such, became involved in the IPCC, the Intergovernmental Panel on Climate Change. The IPCC has been an important body in the formation of global opinion about what is happening to global warming. It's a very interesting process, which I think is unique, by which scientists, working through a series of panels, have produced consensus statements which have been taken as the consensus view of the scientific community by governments. So instead of each country working on its own, there has been a national and international consensus formed which has been extremely influential. John has been at the heart of that.

So without further ado, I am going to ask John to give his lecture which is entitled "Global Warming - the Latest Science and Its Challenge".

Introduction.

Ladies and Gentlemen, it's a pleasure to be here. I gave a lecture here about 3-4 years ago on the same topic, but of course things have moved on since then. And I'm delighted to be here again. In the third week of January I was in Shanghai at the final meeting of working group 1 of the IPCC - that's the Science Assessment Working Group - to agree a policy-making summary. At that meeting there were 99 countries represented, each with their own delegates. We had simultaneous translations into six languages; countries of all shades of opinion regarding the climate change issue were present; and the world scientific community was represented by 45 leading scientists all of whom had been involved in writing, reviewing or helping with the fourteen chapters and 900 pages which make up the full report. The full report will be published by the Cambridge University Press in July 2001.

There was a very good dialogue between the scientists and the countries' delegates. The purpose of the meeting was to agree the Summary for Policymakers (SPM) of the Scientific Assessment, about 10 pages long. We went through it sentence by sentence, bullet by bullet, over four days and much of the nights in between and everyone -delegates and scientists - agreed with the final scientific message. It's a remarkable process: it's wonderful to see the discipline of science in action as a large group of scientists struggle with their responsibility to create clear messages and to say what they know, explaining just how certain they are, and also to explain the areas of large uncertainty. In this IPCC report, for the first time, we have tried to quantify rather specifically the degrees of uncertainty.

The agreed statement went on the Internet straight away (the IPCC web site is www.ipcc.ch) and within three weeks there were 1 million hits on that site. That's not bad for the Internet - there may be other sites, of course, that had more hits, but there are not many respectable ones!