The latest round of international climate change talks began yesterday with the now perennial warning about the need for greater urgency from governments as they battle to curb global greenhouse gas emissions.
Speaking at the opening of the annual week of talks, the head of the UN's climate change secretariat, Christiana Figueres, warned diplomats they "must do more and do it faster".
She warned governments had already used a third of the time between the 2011 Durban commitment to finalise a new international treaty and the 2015 deadline for agreeing that treaty.
The week-long talks follow the release last week of fresh data from the Scripps Institution of Oceanography
in San Diego that suggests for the first time in human history concentrations of carbon dioxide in the atmosphere are set to rise above 400 parts per million
(ppm) for sustained lengths of time from next month.
Climate scientists have long maintained that concentrations need to be kept below 350ppm if the world is to stand a reasonable chance of meeting international targets to keep average temperature increases below 2C, while concentrations of above 400ppm put the planet on track for levels of warming deemed 'dangerous' by the international community.
"I wish it weren't true, but it looks like the world is going to blow through the 400ppm level without losing a beat," said Scripps geochemist Ralph Keeling. "At this pace we'll hit 450ppm within a few decades."
Our situation seems so typical of the breakdown of societies described by Jared Diamond in Collapse.