That is a vital step away from the 22-year-old dogma which has bedevilled the geopolitics of climate change: that the world can be neatly divided into developed countries, which must bear all the cost of curbing emissions, and the rest of the world which can concentrate on economic development.
What is equally clear is that the form of the commitments countries will undertake - "independent nationally determined contributions" in the jargon - will vary widely in their nature and level of ambition.
And Lima was unable to agree that the offers countries tabled have to be in a form that makes them able to be compared as to time-frames and base years or scope and coverage, or why they consider them fair and ambitious given their national circumstances.
Climate Change Minister Tim Groser argues that abandoning the top-down uniformity of the Kyoto Protocol is a geopolitical necessity which reflects entirely different policy environments among even the big three emitters, China, the United States and Europe.
China is prepared to commit to its emissions peaking before 2030, but not to a specific level, and to serious targets for emissions-free electricity generation.
The US Congress will not agree to be legally bound to an agreement if China is not, but the Administration has offered a target which represents a significant reduction in emissions. Europe continues to lead the pack with an offer to reduce emissions to 40 per cent below 1990 levels by 2030.
Groser says that at this point the focus needs to be on a wide-ranging agreement covering say 80 per cent of global emissions rather than how far the aggregate pledges fall short of what scientists say is needed to avoid dangerous climate change - lest the best be the enemy of the good.
The Lima accord also agrees post-2020 pledges will represent progress beyond what countries have already undertaken to do.
That suggests New Zealand's target will have to better the 5 per cent reduction from 1990 levels which is our commitment for the period out to 2020.
Trouble is, actual emissions are running 25 per cent above 1990 levels and climbing, unconstrained by any meaningful carbon price from the emissions trading scheme.
The post-1989 "Kyoto" forests which have generated credits to offset that emissions growth will have flipped from being a net sink to a net source of emissions by the 2020s.
It is difficult to make big gains from decarbonising electricity generation when three-quarters of it is renewable already.
And nearly half of national emissions arise from the bodily functions of livestock, which are harder to redesign than the propulsion systems of vehicles, for example.
So coming up with a "respectable" target for the post-2020 period, as the Government must before May next year, will be challenging, Groser says, especially as the key legally binding ground rules for the international agreement, covering for example access to international trading and accounting for land use change and forestry, have yet to be agreed.
