Here it is: the future of the world, in 23 pages
It is about the size and weight of a theatre programme and when it was published in Valencia, Spain, at the weekend, the first eagerly grabbed copies were held together by a hastily punched staple. Yet these 23 pages are crucial for the future of the world.
This is the key document on climate change, and from now on you can forget any others you may have read or seen or heard about. This is the one that matters. It is the tightly distilled, peer-reviewed research of several thousand scientists, fully endorsed, without qualification, by all the world's major governments. Its official name is a mouthful: the Policymakers' Summary of the Synthesis Report of the United Nations Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment. So let's just call it The Synthesis.
It is so important because it provides one concise, easily-readable but comprehensive text of facts, figures and diagrams – in short all the information you need to understand and act on the threat of global warming, be you a politician, a businessman, an activist or a citizen (or for that matter, a doubter).
The Synthesis has been distilled from more than 3,000 pages of research published in the three separate parts of the IPCC's Fourth Assessment Report, or AR4, during the course of 2007 – on the science of climate change, on its potential impacts, and the possible remedies.
These individual sections – published in Paris in February, in Brussels in April and in Bangkok in May – spelled out comprehensively that the Earth could warm by an average of up to 6C during the course of the coming century, and that this would be catastrophic in its impact for human society, most of all the poor in developing countries; but they also offered hope that the problem was solvable, if the governments took rapid and decisive action to reduce the greenhouse gas emissions causing the warming.
The IPCC, awarded the Nobel Peace Prize this year (along with Al Gore) for its efforts to raise awareness of climate change, was set up by the UN in 1988 and published its first assessment, sounding the initial warning about rising temperatures, in 1990; it issued subsequent reports in 1995 and 2001. But this year's fourth assessment has an importance all its own.
For it is the one where scientists now feel confident enough to declare that the warming world is a phenomenon beyond all doubt, and that the likelihood of this being caused by the human actions of putting greenhouse gases into the atmosphere – and not say, by increased solar activity, as some have argued – is greater than 90 per cent.
For all but the most perverse of sceptics, it ends the basic argument. And it also urgently warns that the risks are greater, and possibly closer in time, than was appreciated even six years ago, when the third assessment was published.
It is chapter and verse, it is Holy Writ: you may not agree with it, but this (backed up by the full reports) is what the world scientific community thinks. Its opening words are magisterial – almost Biblical – in tone. "Warming of the climate system," it pronounces, "is unequivocal". It goes on to spell out that the atmosphere is rapidly warming, snow and ice are melting across the world, and the global sea level is rising at an increasing rate; yet the problem is solvable if governments act decisively.
It is of immediate importance: for the 10,000 ministers, diplomats, officials and civil servants from every country in the world who are assembling in Bali, Indonesia, in two weeks' time to try to sketch out a new international climate treaty to follow the bruised and battered Kyoto protocol.
The Bali conference was put back by a month so that the participants could be in possession of The Synthesis for the talks, and the document will provide the essential background information against which all delegates will work. "We expect to see their personal copies return from Bali, battered and worn from frequent use, with paragraphs underlined and notes in the margin," said Stephanie Tunmore of Greenpeace.
Because all governments adopted The Synthesis by consensus (after a week's negotiations in Valencia), it means they cannot disavow the underlying science and its conclusions (although it does not commit them to specific courses of action).
In Bali, delegates will attempt to set a path forward to a replacement treaty for Kyoto, which runs out in its present form in 2012. The original protocol called on industrialised countries such as the US and Britain to cut their carbon dioxide emissions, without imposing a similar task on developing nations such as China and India – which was one of the reasons President George Bush withdrew.
But no new treaty will work unless it brings together both the US and China – now jointly the world's greatest CO2 producers – along with the rest of the international community in a unified attempt to bring emissions under control.
The Synthesis shows in its 23 short pages – just 5,000 words – exactly why that is necessary. It shows it to governments and it shows it to all of us. It will be one of history's most important documents, and because of the phenomenon of the internet you can read it in a matter of moments and judge for yourself.
Download it at www. ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_spm.pdf
Latest statistics and shocks still in store
* 11 of the past 12 years (1995-2006) rank among the 12 warmest years in instrumental records of global surface temperatures (since 1850)
* Global average sea level has risen since 1961 at an average rate of 1.8mm per year – but since 1993 at an average rate of 3.1mm
* Temperature changes will depend on how much CO2 is emitted, but different scenarios see the increase by 2100 ranging from 0.3C to 6.4C
* Up to 30 per cent of the world's species are at increased risk of extinction after a 2C temperature rise
* Between 75 million and 250 million people in Africa could suffer water shortages by 2020; in Asia, heavily-populated "mega-deltas" are at greatly increased risk of flooding; tropical forest in eastern Amazonia will turn to savannah by mid-century