Quietly in public, loudly in private, climate scientists everywhere are saying the same thing: it's over.
The years in which more than 2degrees of global warming could have been prevented have passed, the opportunities squandered by denial and delay.
On current trajectories we'll be lucky to get away with 4degrees.
Mitigation (limiting greenhouse gas pollution) has failed, now we must adapt to what nature sends our way. If we can.
This was the repeated whisper at the climate change conference in Copenhagen earlier this month.
It is more or less what Bob Watson, the environment department's chief scientific adviser, has been telling the British government.
It is the obvious, if unspoken, conclusion of scores of scientific papers.
Recent work by scientists at the Tyndall Centre for Climate Change Research, for instance, suggests that even global cuts of 3per cent a year, starting in 2020, could leave us with 4 degrees of warming by the end of the century.
At the moment, emissions are heading in the opposite direction at roughly the same rate.
If this continues, what does it mean? Six? Eight? Ten degrees? Who knows?
Faced with such figures, I can't blame anyone for throwing up their hands. But before you succumb to this fatalism, let me talk you through the options.
Yes, it is true mitigation has so far failed. Sabotaged by Bill Clinton, abandoned by George W. Bush, attended halfheartedly by the other rich nations, the global climate talks have so far been a total failure.
The targets they have set bear no relation to the science and are negated anyway by loopholes and false accounting.
Nations such as Britain, which is meeting its obligations under the Kyoto protocol, have succeeded only by outsourcing it's pollution to other countries.
And nations such as Canada, which is flouting its obligations, face no meaningful sanctions.
Lord Stern made it too easy, he appears to have underestimated the costs of mitigation.
As the professor of energy policy Dieter Helm has shown, Stern's assumption that our consumption can continue to grow while our emissions fall is implausible. To have any hope of making substantial cuts we have to reduce our consumption and transfer resources to countries such as China to pay for the switch to low carbon technologies.
As professor Helm says, ''there is not much in the study of human nature and indeed human biology to give support to the optimist''.
But we cannot abandon mitigation unless we have a better option, but we don't.
If you think our attempts to prevent emissions are futile, take a look at our efforts to adapt.
Germany is spending $US600million ($A871million) on a new sea wall for Hamburg and this money was committed before the news came through that sea-level rises this century could be two or three times as great as the Intergovernmental Panel on Climate Change has predicted.
The Netherlands will spend $3.19billion on dykes between now and 2015 and again, they are likely to be inadequate.
The UN suggests rich countries should be transferring between $72billion and $109billion per year to poor countries now, to help them cope with climate change.
But nothing like this is happening.
Rich nations have promised $26billion to help the poor nations adapt to climate change during the past seven years, but they have disbursed only 5per cent.
Oxfam has made a compelling case for how adaptation should be funded. Nations should pay according to the amount of carbon they produce per capita, coupled with their position on the human development index.
On this basis, the US should supply more than 40per cent of the money and the European Union over 30per cent, with Japan, Canada, Australia and Korea making up the balance. But what are the chances of getting them to cough up? There's a limit to what this money could buy anyway.
The Intergovernmental Panel on Climate Change says that ''global mean temperature changes greater than 4degrees above 1990-2000 levels'' would ''exceed ... the adaptive capacity of many systems''.
At this point there's nothing you can do, for instance, to prevent the loss of ecosystems, the melting of glaciers and the disintegration of major ice sheets.
Elsewhere it spells out the consequences more starkly. Global food production, it says, is ''very likely to decrease above about 3degrees''. Buy your way out of that.
And it doesn't stop there. The IPCC also finds that, above 3degrees of warming, the world's vegetation will become ''a net source of carbon''.
This is just one of the climate feedbacks triggered by a high level of warming. Four degrees might take us inexorably to 5degrees or 6degrees, the end for humans of just about everything.
Until recently, scientists spoke of carbon concentrations and temperatures peaking and then falling back.
But a recent paper in the Proceedings of the National Academy of Sciences shows that ''climate change ... is largely irreversible for 1000 years after emissions stop''.
Even if we were to cut carbon emissions to zero today, by the year 3000 our contribution to atmospheric concentrations would decline by just 40per cent. High temperatures would remain more or less constant until then. If we produce it, we're stuck with it.
In the rich nations we will muddle through, for a few generations, and spend nearly everything we have on coping. But where the money is needed most there will be nothing.
The ecological debt the rich world owes to the poor will never be discharged, just as it has never accepted that it should offer reparations for the slave trade and for the pillage of gold, silver, rubber, sugar and all the other commodities taken without due payment.
Finding the political will for crash cuts in carbon production is improbable. But finding the political will when the disasters have already begun to spend adaptation money on poor nations rather than on ourselves will be impossible.
The world won't adapt and can't adapt, the only adaptive response to a global shortage of food is starvation.
Of the strategies it is mitigation, not adaptation, which turns out to be the most feasible option.
Yes, it might already be too late even if we reduced emissions to zero tomorrow to prevent more than 2degreesC of warming. But we cannot behave as if it is, for in doing so we make the prediction come true.
Tough as this fight may be, improbable as success might seem, we cannot afford to surrender. Guardian