By Richard Black
Environment correspondent, BBC News website
In awarding the Nobel Peace Prize to Al Gore and the Intergovernmental Panel on Climate Change (IPCC), the committee has signalled its view that climate change is now one of global society's defining security issues.
Mr Gore has taken the message of climate change to the public
Just look down the list of previous winners and the issues they represented.
Nuclear weapons, nuclear proliferation, the Middle East, North Korea, East Timor, Northern Ireland, Soviet break-up, the ending of South African apartheid, landmines, the Middle East again, South Asian rural poverty... all things which threatened to affect, and in many cases did affect, the well-being of citizens inside and outside the conflict zones.
Now the Nobel Foundation has added climate change to the list. And the conflation of the laureates is interesting.
In the IPCC they have picked the body which has done most to establish the science of climate change and project what it may mean for the natural world and human society.
As a heavyweight political figure... Mr Gore gained the attention of gadfly media organisations in a way that no scientist or activist ever could
If the IPCC has been the global leader, Mr Gore has been its minstrel, taking the message of climate change to the public in a way that no-one had previously attempted.
There is some irony in the twin award, given the High Court judgement handed down in Britain this week which found that Mr Gore's film An Inconvenient Truth contained some rather important errors, despite being truthful in its central message - which was derived principally from the IPCC.
Al Gore was by no means the first to try to engage the public on climate change - that accolade belongs partly to a few pioneering scientists, but mostly to the environmental movement, to groups such as Greenpeace and Friends of the Earth.
But many of their top players have been in scarcely-concealed despair over their inability to get people interested.
George Marshall of Rising Tide said a few years back: "For 15 years, environmental activists, myself included, have been pursuing this tried-and-tested model (of public awareness-building).
"Our call to action has been made against a backdrop of serious warnings from scientists. And yet there is still no vocal mass movement against climate change in any country.
"Where did we go wrong?"
As a heavyweight political figure in the most powerful and one of the most climate-sceptical countries on Earth, Mr Gore gained the attention of gadfly media organisations in a way that no scientist or activist ever could.
Ole Danbolt Mjoes announced the winners on Friday
He also revealed himself as a superb communicator - sharp, witty, and engaging.
And in the political sense, he had been there, done it, worn the t-shirt and eaten the burger.
For eight years, his finger had been a heartbeat away from the button deploying the world's most terrifying nuclear arsenal.
Who would not listen when he warned of a catastrophe not nuclear, but climatic, in nature?
And the non-governmental organisations, struggling to find a new relevance for themselves now that Tony Blair, Al Gore, Jacques Chirac and Ban Ki-Moon have stolen their clothes, have applauded the Nobel award.
WWF's Hans Verolme spoke of "our gratitude to Al Gore for championing this issue".
Chris Miller of Greenpeace said the former vice-president had "inspired many around the world to redouble their efforts to protect the planet".
Putting in the hours
You could argue that Mr Gore was fortunate in beginning his campaign at a time when the scientific picture on climate change was becoming clearer.
For that, he must thank the IPCC; the bureaucrats who manage it, the hundreds of scientists who take part in its discussions, and the thousands of other scientists whose research feeds into it.
Most science is not glamorous. Unless you spend time close to scientists, it is difficult to appreciate the sheer mind-numbing tedium which many of us would feel if we put ourselves through their daily routines.
INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)
Established in 1988 by the World Meteorological Organisation (WMO) and the United Nations Environment Programme (Unep)
Made up of more than 2,000 leading climate experts
Tasked with assessing scientific data on the risk of human-induced climate change, its potential impacts and options for mitigation
Does not carry out any research of its own
First Assessment Report published in 1990; its Fourth Assessment Report called Climate Change 2007 to be published mid-November
My favourite example comes from a different type of scientist, albeit a Nobel Laureate, Sir John Sulston, who scooped the Medicine Prize in 2001.
In his book The Common Thread, he relates how his Nobel-rewarded research involved looking down a microscope for several hours at a time, every day, for more than a year, drawing the patterns he saw in the cells of tiny nematode worms as they replicated and died.
Sex, drugs and rock and roll it is not.
Some of the scientists involved in painting the climate picture are engaged in work of equivalent, usually thankless tedium, and this Nobel Prize is in part an award for them.
Their years of labour led to the IPCC's latest analysis, that it is more than 90% certain that humans are the prime agents behind changes now being observed in the Earth's climate.
Combined with the panel's soberly-written projections of the impacts of those changes, it is that certainty which Mr Gore and his like can now draw on when they talk about climate change in the corridors of power and on our movie screens.
Over the last year it has been possible to detect a sea-change in the way climate change is regarded and discussed.
Such impressions are necessarily nebulous. But there seems to be more acceptance of the science at the top tables in sceptical governments.
And it is worth remembering that what emerges in the IPCC's headline reports is endorsed by representatives of the world's most important governments, so it is not just a bunch of scientists making just another study.
Former World Bank economist Sir Nicholas Stern has made the economic case for tackling the problem soon and taken it to finance ministers and corporate chiefs around the world.
Partly spurred on by electoral concerns, US President George W Bush and Australia's John Howard have both endorsed the need to curb greenhouse gas emissions more explicitly than ever before, though their own domestic policies fall short of what the IPCC or Mr Gore would recommend - as do those of many still nations within the Kyoto Protocol process, including Britain's.
Whether any of this will make a difference in December, when delegates gather in the tropical heat of Bali for the United Nations climate convention annual meeting, is an open question.
The Nobel accolade for the scientific collective and the great communicator perhaps make it a little more likely.