Every United Nations conference on global warming since the 1992 Earth Summit in Rio de Janeiro - and there have been eight such meetings so far - is populated by the same cast of characters. They haunt the corridors and the lobbies, buttonholing delegates to find out what's happening and to put forward their points of view.
These characters on the climate-change circuit range across the spectrum from Dr Jeremy Leggett, science director of Greenpeace International, who wants action on the issue, to Mr Donald Pearlman, a US lawyer, and his allies in the Global Climate Coalition of oil, coal and motor industry interests, who always seek to block progress.
Not many people have heard of Mr Pearlman, though his influence has been enormous. He has never missed a meeting and is believed to have read every single line of well over 1,000 UN documents on climate change.
Clients of his Washington law firm, Patton, Boggs and Blow, include such industrial giants as DuPont, Exxon, Shell and Texaco.
A profile in Der Spiegel during the 1995 First Conference of the Parties to the UN Climate Change Convention in Berlin memorably described this publicity-shy lawyer as the "High Priest of the Carbon Club" and said his aim was to "ensure that climate protection negotiations end in the nevernever land of vague declarations."
Negotiations under the convention work on the basis of consensus: everyone has to agree on a text before it can be adopted. This inherent weakness in the process has been exploited over and over again by the fossil fuel lobby, and Mr Pearlman in particular, to weaken the wording of both scientific and political documents.
As one leading environmentalist put it, "He is there arguing over individual words in the text, watering down the science so there are more uncertainties . . . Having succeeded in this ploy, his lobby can and do argue at the next meeting and all the ones afterwards that the science is uncertain and therefore it is too early to take action."
He "systematically uses" delegates from the Gulf states, Der Spiegel said, to "undermine the credibility of scientists" at meetings of the Intergovernmental Panel on Climate Change. They "engage in endless hair-splitting" and, at one stage, a Kuwaiti delegate even submitted, in Mr Pearlman's handwriting, proposals to change the text.
The US fossil fuel industry, which Mr Pearlman so assiduously represents, has spent millions of dollars in recent years on what the Worldwatch Institute in Washington regards as a "disinformation" campaign to prevent President Clinton taking action on climate change.
Yet Greenpeace is not without allies. Its biggest coup, engineered by Dr Leggett, was to persuade significant elements of the world's insurance industry to climb on board.
What Dr Leggett set out to do was to create a counter-lobby, which would become as important as the coal and oil industry group in pulling the other way. He began talking to insurers, telling them that the thousands of claims from householders with subsiding houses built on London clay were "merely the tip of the global warming iceberg."
Paul Brown, author of a definitive book on climate change, notes that between 1975 and 1993 Britain's bill for subsidence totalled £2.5 billion. Problems began mainly in the long dry summer of 1976 but were repeated in the 1980s.
Yet another crop of claims emerged as a result of the very hot and dry 1995 summer. The ground underneath these houses was quite literally cracking up.
Many of the damaged houses were Victorian which had stood on clay foundations for 100 years, yet over the spread of a few years thousands required major repairs.
No wonder insurance companies have introduced a differential premium for houses built on clay; this is "England's first global warming insurance premium," as Paul Brown called it.
It was Greenpeace's 1994 report, The Climate Time Bomb, detailing a huge number of natural disasters worldwide, that made the insurance industry sit up and take notice. In the US alone, 21 of the largest 25 insured catastrophes on record occurred in the past 10 years, and 16 of the 25 involved a combination of wind and water.
The league table for 1992 and 1993 included Hurricane Andrew in the US (£16.7 billion), flooding in the US Midwest (£8 billion), gales in the US, Canada, Cuba and Mexico (£3.3 billion), Cyclone Iniki in Hawaii (£1.7 billion), flooding in Belgium, France, Germany and the Netherlands (£1.3 billion) and Typhoon Polly in China (£1 billion).
Dr Leggett, who assembled insurance executives for a press briefing at the 1995 Berlin conference, said later: "The worst case for insurers is very bad indeed. I have now been personally told by people at the top of the industry, in Munich, Zurich, London, New York and Tokyo that climate change could bankrupt the industry."
The fossil fuel lobby's biggest ally is public apathy. Public interest in "saving the world" has waned quite perceptibly since the Earth Summit. The issue is seen by ordinary people as too complex and the solutions too difficult to contemplate.
But Chancellor Helmut Kohl put it up to us in 1995 when he said: "Preserving Creation and securing sustainable development is a task for the whole of mankind, a task which no one, no state, no economy and no individual, must shirk."