If you’ve been following the news over the weekend, you’ll probably have noticed Blair’s back, and he brings glad tidings to the world of men. The disgraced ex-premier and war criminal flew to Japan on Friday to discuss his plans for a global climate deal, establishing binding targets for reductions in greenhouse gas emissions by 2050. The Guardian, which happily landed an interview with the guy, told us of Blair’s “ambitious plan for a global climate change deal” which has “been in gestation ever since he left office”. The word “ambitious”, indeed, appears three times in this interview (only once attributed to Blair – evidently the paper was kind enough to echo and amplify his thoughts).

Much of the mainstream press also echoed the adulation of Blair’s “ambitious” new plans. “My God,” writes the Guardian’s Martin Kettle, “now even Tony Blair has got religion on climate change.” John Rentoul in the Independent could barely restrain his lofty estimation of the man’s vision – Blair’s is an “absurd ambition”, he writes – but one which is nonetheless “admirable, however far it falls short”. The same message – combining a lofty appraisal of Blair’s goals with cynicism about the possibility of achieving them – was peddled by the Times. In their headline’s words: “After world peace, Tony Blair’s next mission is to save the planet”. Even Mark Lynas, of all people, gets in on the act – granted, in a more measured and qualified way – writing that Blair may be a “champion” for climate change campaigners; a “man whose time has come”.

So what does his plan actually amount to? According to the BBC, Blair is trying “to guide attempts to secure a deal involving China and the US to slash emissions by 50% by 2050”. Why 50%? In Blair’s words: “There is no point producing something that is not politically doable.”

On the other hand, is there any point producing a target that won’t keep us in the climatic safe zone, avoiding the “tipping points” we need to avoid to prevent runaway climate change? Certainly, a binding agreement would be better than the nothing we have at the moment; and as Blair suggests, this initiative may set the stage for future agreements. Otherwise, amidst the talk of Blair’s “ambitious” plans, the question is barely raised.

It’s time we started raising it rather more forcefully. According to what now constitute the more conservative estimates, “The task of cutting greenhouse gas emissions enough to avert a dangerous rise in global temperatures … would require the world to cease carbon emissions altogether within a matter of decades.” In February, research by Damon Matthews, from Concordia University in Canada, and Ken Caldeira, from the Carnegie Institution for Science, Stanford, USA, published in Geophysical Research Letters, found that “[g]reenhouse gas emissions will have to be eliminated completely to stabilise the Earth’s climate and prevent temperatures from rising.” As New Scientist reported,

“Roger Pielke, a climate policy expert at the University of Colorado in Boulder, agrees with the findings. “This research makes the case that simply stabilising concentrations is insufficient to stabilise temperatures. Their argument, if widely accepted, raises the bar on what it means to mitigate climate change,” he says.

“Matthews and Caldeira warn that current emissions targets for 2050 are insufficient to avoid substantial future warming. Instead they believe that we need to eliminate emissions, or find a way of actively removing carbon dioxide from the atmosphere.”

This research echoed the findings of a study published last October by Andrew Weaver and colleagues at the University of Victoria in Canada, that “[o]nly the total elimination of industrial emissions [by 2050] will succeed in limiting climate change to a 2°C rise in temperatures”. As Weaver adds, “There is a disconnect between the European Union arguing for a 2°C threshold and calling for 50% cuts at 2050 – you can’t have it both ways”. And he’s not alone.

“Tim Lenton, a climatologist at the University of East Anglia in the UK, agrees that even the most ambitious climate change policies so far proposed by governments may not go far enough. “It is overly simplistic [to] assume we can take emissions down to 50% at 2050 and just hold them there. We already know that that’s not going to work,” he says.

“Even with emissions halved, Lenton says carbon dioxide will continue building up in the atmosphere and temperatures will continue to rise. For temperature change to stabilise, he says industrial carbon emissions must not exceed what can be absorbed by Earth’s vegetation, soil and oceans.

“At the moment, about half of industrial emissions are absorbed by ocean and land carbon “sinks”. But simply cutting emissions by half will not solve the problem, Lenton says, because these sinks also grow and shrink as CO2 emissions change.

“People are easily misled into thinking that 50% by 2050 is all we have to do when in fact have to continue reducing emissions afterwards, all the way down to zero,” Lenton says.”

Unfortunately, this itself may not be enough. As the US’s leading climate scientist James Hansen put it last May, “what’s now become clear is that maybe 1 degree Celsius is dangerous, because already we’re seeing on West Antarctica a net loss of ice and the ocean is warming and it is beginning to melt the ice shelves.” In June, Hansen, along with five other scientists “from some of the leading scientific institutions in the United States”, published a report concluding that the dangerous level of man-made greenhouse gases “is much lower than has commonly been assumed. If we have not already passed the dangerous level, the energy infrastructure in place ensures that we will pass it within several decades”. A “feasible strategy for planetary rescue” therefore “almost surely requires a means of extracting [greenhouse gases] from the air.”

Since this report was published, the data from the melting of arctic sea ice has worsened considerably. As Mark Serreze, senior scientist at the US government’s snow and ice data center in Colorado, put it in December, “The Arctic is screaming”. According to Dr. Olav Orheim, head of the Norwegian International Polar Year Secretariat, it is “highly possible” that “the ice cap in the Arctic will all melt away” this year. As Hansen told one interviewer in February,

“we will have to restore the point of energy balance because as it stands now we will lose the arctic sea ice without any more greenhouse gases, because there is additional warming that’s in the pipeline, because the planet is out of energy balance, just because of the inertia of the system.

“That means we would have to reduce the amount of CO2 at least to the 350ppm level, and we are already at 385. So, we’ve actually got to go backwards …

“We can see that 385ppm is really going to produce a significantly different planet. And also just looking at what’s now happening, not only in the Arctic, and the fact that the ice sheets are not stable with the current CO2 amount, and the fact that the sub-tropical regions have expanded noticeably by a few hundred kilometres, that’s enough to effect the southwest US, the Mediterranean, and Australia I should point out.

“So there’s a lot of things, also coral reefs are another example. If we want to reduce the stress on coral reefs, we have to both reduce CO2 and the warming of the ocean temperatures. So there are a number of things like that which make it clear that we’ve already passed the target level that we should be aiming for.”

Stripping carbon from the atmosphere is possible, Hansen notes, principally through “improved agricultural and forestry practices” (which, he adds, we’re currently undermining). How long we have in terms of time is something we simply don’t know:

“you know we’re pushing the atmospheric composition beyond the level which will give us a stable climate, so we’re overshooting the acceptable level. And we don’t know how long we can stay in a state where we’ve overshot that level. Obviously, if you overshoot for one day, that’s not going to cause a problem. It’s a question of how many years can you leave it at a level which is going to cause long term unacceptable impacts, like instability of the ice sheets. …

“That’s the key question, but it’s a very hard one because the systems in question are non-linear. Inherently it’s very difficult to predict a point of collapse. Whether you’re talking about an ice sheet collapsing or whether you’re talking about an ecosystem collapsing because as some species go extinct, that effects others because they’re all connected. So it’s just inherently a very difficult non-linear problem, and the models are just not up-to snuff as far as giving us the numbers for that. We can’t simulate the responses that are occurring right now in Greenland and West Antarctica.”

As John Houghton, formerly both Co-Chair of the Intergovernmental Panel on Climate Change and Director General of the UK Metrological Office, adds, “[t]he urgency of action on climate change is being recognised at an ever increasing rate, with new evidence constantly coming to light.”

We simply have no time to lose. And what is abundantly clear is that none of this can happen at all unless we phase out coal power. The British government, as should also be abundantly clear by now, is going in the opposite direction – both stepping up the extraction of coal from the ground, and building a new generation of coal-fired power plants. If we want to prevent this from happening, as both Hansen and Al Gore have suggested, direct action has to be a serious part of our efforts (and, as we now know, this year’s climate camp is set to be targeting the site of the proposed new coal-fired station at Kingsnorth in Kent). On its own, one big climate camp a year is unlikely to take us where we need to go. But, if part of a concerted, growing campaign, direct action works; it has worked before; and it can work again. Moreover, the necessary target is achievable. As Hansen says:

“I think an initial target of 350 is doable provided we phase out coal, and although that sounds like a real tough job, in fact it’s doable and if we don’t do it there is no question, if you look at the times in the earth’s history when there was that much CO2 in the atmosphere it was a completely different planet. We have to do it and it is doable … if we compare it to how much effort we put into World War II, it’s a doable job and the incentives are just as great as they were then.”

The original purpose of this post was to draw attention to the looming chasm between what the mainstream media lauds as “ambitious” and what the science is telling us are our minimum necessary targets. What I’m particularly struck by, though, is the extraordinary sense of hope and possibility with which Hansen himself seems to be able to tell us the apparently unthinkable. The mainstream media’s version forms an extraordinary contrast: a totally inadequate target not only rendered “ambitious”, but in some cases so ambitious that it’s barely worth imagining we can possibly achieve it. We are presented with two highly divergent visions of the future. Only one of them can possibly bear thinking about.