I have just spent 10 days traveling across Africa to assess the impact of climate change. From north to south the broad observations are remarkably similar. More floods, droughts, storms and changing seasons are being experienced: the heatwaves are getting longer and more frequent; the storms more intense; the nighttime temperatures higher; the farmers see new diseases and pests; and the growing seasons appear disrupted. On top of that, the marginal areas are turning to desert and cities are becoming unbearably hot. The peer-reviewed science is still sketchy, but it's the best there is in a continent starved of research funds and it is consistent with the latest models done by the Intergovernmental Panel on Climate Change.
What is less predictable is the extreme variability of governments' responses to this unfolding drama. Having dragged climate change from seemingly nowhere to the top of the global agenda only two years ago, and brought more than 100 heads of state to Copenhagen in 2009 to sign a historic new deal, the UN generals sitting in Brussels, Washington, Beijing and Delhi have not just marched it down, they seem now to have disbanded the troops and sent them back home.
Before Copenhagen we were told the world would stop at nothing to get an equitable, fair agreement. Then, we were told, a deal could be done in a week. After Copenhagen, it was so important for the future of humanity that we could expect a deal within the year. That then morphed to two or three years, and now ministers and senior diplomats are playing down expectations even further by suggesting it may take another four years of talks to come up with a plan that could, possibly, come into effect in 2020.
In other words, some leaders of the rich and big-emitting countries have lost interest and political momentum and want to consign the talks, like those on world trade, to a never-ending, never-achieving, low-grade, low-profile discussion to take place in backrooms without anyone listening or caring much. They may profess concern, but there is little evidence they want to act.
But something else has changed since 2009, too. The 175 or more developing countries are now talking more as one, and the great illusion trick of the rich world is wearing thin. What has changed, they ask? The science of climate change is firmer than it ever was. A 2C-4C temperature rise still means that Africa fries and the polar bears die out, that Bangladesh and Egypt drown, the droughts in Latin America and Ethiopia continue to worsen, and the poorest communities and small-island states, who have the least resources to adapt, will be hurt the hardest.
Here we are, they say, in the midst of a 10-year drought and food crisis in Africa, with unprecedented flooding in south-east Asia and Central America, and North America, Australia and Europe having just had some of their most extreme climatic years ever. Emissions and temperatures are higher than ever, people everywhere are genuinely concerned, but the big emitters are still not prepared to do anything. What more do they need to be persuaded to act swiftly?
Any postponement of a deal, they say, is not just dangerous politics, it is criminal negligence, consigning the poor to oblivion. If treasuries can find trillions to bail out dodgy banks, if financiers can be paid hundreds of millions in bonuses and the politics of Europe can be redrawn in just a few weeks, then why can't the rich and big-emitting countries make a deal to try to avert what could be the greatest problem the planet has faced? In short, why are world leaders gambling with the fate of the planet?
The answer, in short, is because the talks are becoming disconnected from reality. They are in danger of being no more than a diplomatic sideshow for leaders to profess concern and responsibility, an occasion to do nothing more than defend the status quo and protect existing economic self-interests.
We saw how the big emitters were playing the game last month. After six months of intense but productive behind-the-scenes negotiations before the Durban conference, it appeared that both rich and poor countries had agreed on how the giant "green climate fund", planned to deliver the billions of dollars that may one day flow from rich to poor countries via carbon credits, would work. The consensus report was to go forward to Durban as a ready-to-roll package. It would have constituted a major diplomatic success, but at the very last minute and without warning, the US and Saudi Arabia pulled out. With so much at stake, there were loud appeals by some countries to prolong the meeting or hold another, but these were dismissed by the rich countries. It does not mean agreement on the fund cannot be reached at Durban next week, but it makes it that much harder and more likely that it won't.
Equally, the fate of the Kyoto treaty is in the balance again. This is the treaty under which all developed countries except the US legally commit to reduce emissions. It looks increasingly as if it won't survive Durban, because Japan and Russia have openly stated they do not want to continue with it, and Europe is divided. Those against want Kyoto replaced with a system of voluntary pledges by developed countries, while developing countries are also pressed to take on more commitments. It is a recipe for blame and recrimination. Meanwhile, the thorny but vital subject of emission cuts will not be discussed, kept off the agenda by the big polluters.
Now the developing countries are furious. They have already pledged that the Kyoto protocol must be saved and not buried at Durban, but this week we saw the first stirrings of a proper UN revolt, with senior diplomats from several continents saying they are considering a call by the former Costa Rican president Jose Maria Figueres to "occupy Durban". This could mean little more than a symbolic boycott of a morning meeting or a polite ambassadorial sit-in, but behind the grandstanding and breast-beating there is no disguising the mounting anger and potential for fireworks.
For the big emitters it is now a zero-sum game. The poor hold all the moral cards and will undoubtedly play to the galleries back home. The US and Europe, already looking like a wounded, shabby elite representing the 1%, will be pilloried.
The prospects for Durban are slim. The energy and climate change secretary, Chris Huhne, argued on Thursday that a global deal covering all major economies was not a luxury or an optional extra but "an absolute necessity". Fine words, but startlingly similar to those of Ed Miliband talking before Copenhagen, and David Cameron just before Cancun. No one doubts Huhne's desire to make progress, but convincing the US to stop playing with the lives of the poorest or China to brake their economic rise may be too much to expect.