Climate visions: a widening divide?
At the UN climate summit in Copenhagen
It's been two years minus just over a week since 192 governments agreed to formulate a new deal on climate change.
There are now just under two weeks left before they're due to conclude it.
As anyone who's employed builders will know, overruns and unanticipated problems are nothing new in many walks of life; so perhaps the already acknowledged failure to finalise a new treaty here shouldn't be regarded too harshly.
But at least if you know fundamentally in which direction you are walking, there's a chance of arriving at the same place eventually.
In the hours before the Copenhagen talks officially open, it appears that if anything, the paths of the industrialised and developing country blocs are moving away from each other.
Last week, the BASIC group of countries - Brazil, South Africa, India and China - put forward proposals (originating from China) detailing some principles they would like to see in any agreement here.
As I wrote in my last post, these included a rejection of binding constraints on emissions for developing countries, opposition to international verification of those constraints, and the continuation of emission reductions from developed nations under the Kyoto Protocol rather than any new framework.
As I also wrote, some of this was very much at odds with principles proposed by the Danish host government - presumably with the approval of all other EU states, and reportedly with the approval of the US.
As I write this post on Sunday evening here, the G77/China bloc - the disparate collection of 130 countries ranging in wealth from prosperous Kuwait to impecunious Togo, which acts as the developing countries' main forum - is holding a day-long meeting to agree its opening position.
The indications are that this will take the bloc even further away from the sort of thing favoured by the EU and US.
Steers I've picked up so far suggest that over half the countries in the bloc are now supporting the demand of small island developing states that the end goal of all of this should be to keep the rise in global average temperature since pre-industrial times to 1.5C, rather than 2C.
Translate this to greenhouse gas concentrations, and the demand is stabilisation at 350 parts per million (ppm) of CO2 or equivalent, rather than the 450ppm that's implicit in the proposals of Western countries and the declaration made in July by G8 members and a group of major developing nations.
Other delegates tell me the G77/China group is toughening other demands as the day progresses; we'll see.
Whatever emerges, the general move of toughening puts a different slant on things from the optimism expressed by Yvo de Boer, the UN climate convention's executive secretary.
He is of course factually correct in saying that more countries have put forward pledges on curbing emissions than ever before, and that the level of political commitment shown by heads of government to tackle the issue is unprecedented - as evidenced by the fine speeches made back in September at the UN secretary general's special session on climate change.
More than 100 heads of state and government are due in for the final days of this conference; and many of them could up their "level of ambition", as the UN tends to call it, with the strike of a decisive pen.
But will they? Or will the fundamental divide prove too wide to cross?
Is there yet - after nearly two years of talking - an agreement on how the world should move forward on climate change?