The news on climate change from the emergency science summit in Copenhagen is unremittingly gloomy. Worst-case climate change scenarios appear increasingly likely; the body of opinion seems to be that we’re already failed to restrict warming to the ‘manageable’ level of a two degree increase, and the cost of addressing climate change has increased since Nicholas Stern’s Review. The summit was attended by 2,500 experts from 80 countries. Stern, meanwhile, is perplexed, or perhaps dismayed, by the lack of response by politicians, and the failure of imagination it represents. At least some of the climate change economists are now a bit more cheerful.

Stern said that that he thought that his 2007 report had underestimated the risks of global warming.

“The reason is that emissions are growing faster than we thought, the absorption capacity of the planet is less than we thought, the probability of high temperatures is likely higher than we thought, and some of the effects are coming faster than we thought,” he explained.

In fact, the scientists’ prognosis is unremittingly gloomy.Their starting point is that our chances of keeping global warming to within 2 degrees is increasingly unlikely, given that there has been no visible progress in starting to make the emissions cuts needed to reduce emissions by 50%’ let alone 80%. As a result we need to start planning for a 3 or 4 degree increase. Welcome to dystopia.

The final statement will be published in June, but a report in the Times on the end of conference summary statement is clear enough.

Most of the impact of a four degree rise would be felt by the less affluent world, but there would be significant effects in the rich world as well. Drought would lead to increasing desertification, and food production would be likely to fall – even while the global population is expected to increase to around nine billion. Southern Europe could lose much of its agriculture.

The combination of droughts, famine and other impacts, including floods, hurricanes and the spread of deadly diseases, would mean that many millions of people would starve or be killed in wars over resources. Numbers of refugees would be in the hundreds of millions, perhaps even billions, putting untold pressures on other regions.

Along the way, sea levels could rise by up to a metre (though bad, this is not quite so dramatic as news reports suggested); the Amazon rainforest could be reduced to one-sixth of its present size; and even modest warming could release what was described as a ‘carbon time bomb’ from the presently frozen Arctic soils.

If scientists are gloomy, at least (at last) economists seem more positive; as they say, don’t waste a good crisis. At least the scale of the banking bail-out has made the green investment numbers seem modest. Stern thought an effective ‘green deal’ would take around $400 billion of the current reflation packages.

The Cambridge economist Terry Barker – of the University’s Centre for Climate Change Mitigation Research in Cambridge – suggests that previous models, which suggest that stringent emissions controls reduce economic activity, have assumed that they are being introduced in a world of full capacity and full employment. Not true, even before the financial crisis, and certainly not true now. Barker is quoted at length in Business Green:

“There is some evidence that harder greenhouse gas targets and regulation may actually increase benefits through improved innovation and distribution of low carbon technologies, and increased revenues from taxes or permits,” he said. ” These revenues can be spent to further support new technology and to lower other indirect taxes, ensuring the fiscal neutrality of these measures.”

And more in the New York Times:

“The current global financial crisis must be seen as a timely stimulus to tackling climate change, not a hindrance,” Barker said. “If all G-20 countries adopted a ‘green New Deal’ similar to the one proposed by President Obama, the world economy would be greatly strengthened, especially the sectors producing low-carbon technologies. But global coordination is critical. Any single country’s New Deal may fail if its extra demand for goods and services is met with imports. If we act together, everyone’s exports will increase and we can recover employment much more quickly.”

The end of conference summary statement seems to encapsulate the scientific community’s frustration at the failure of (short-term) political processes to respond to long-term climate catastrophe.

“”The climate system is already moving beyond the patterns of natural variability within which our society and economy have developed and thrived. … There is no excuse for inaction. We already have many tools and approaches – economic, technological, behavioural, management – to deal effectively with the climate change challenge. But they must be vigorously and widely implemented.”

Nicholas Stern was more direct when he spoke to the media after giving his speech:

“Do the politicians understand just how difficult it could be? Just how devastating four, five, six degrees centigrade would be? I think not yet.”

As Kevin Anderson of the Tyndall Centre put it: “Scientists have lost patience with carefully constructed messages being lost in the political noise. We are now prepared to stand up and say enough is enough.”

At least Prince Charles appears to understand this – picking up on nef’s “100-month” warning on climate change in a speech in South America. For the rest of it, it gets more and more like Easter Island every week.