Ideally, the leaders who participated in the climate change negotiations in Copenhagen would have agreed to long-term emissions reductions, backed by short-term reduction targets. Apparently, however, even a 50-per-cent overall reduction target for 2050 was too stringent for too many countries and therefore Copenhagen ended without either long-term targets or short-term yardsticks.
Measurable yardsticks would have required hard decisions by many countries whose publics are not ready for strong action such as the United States; by democratic governments such as Canada that do not wish to lead; and by developing countries such as China and India unwilling to acknowledge that although the developed world has created most of the emissions to date, the fast-developing countries will be responsible for a growing share of emissions in the next half-century.
Instead, what seems to have been agreed upon was a process whereby countries will list their targets voluntarily. A long negotiation will follow to try to make these binding and included in an international treaty. The result was better than a complete collapse of the talks, but it left much of the detailed work for long negotiations ahead.
Copenhagen, therefore, was a predictable disappointment. The gaps coming into the talks between and among countries' positions were too large; the domestic political stakes in some cases were too high; the economic fears too great; the temptation to finger-point too irresistible.
Just as the shift to a de-carbonized economy is a process of great complexity that will stretch over many years, even decades, so international climate-change negotiations are perhaps as complicated a set of talks as it would be possible to imagine.
The technical issues are formidable, such as how to count, monitor and verify emissions, and how to give credit for reforestation or the end of forest-clearing, as in Brazil.
The economic tools are in their infancy, so that reasonable questions can be asked about their efficacy, as in how would a cap-and-trade system work in one country, let alone a number of them together.
The crunch question of pricing carbon - how and at what price? - remains unsettled around the world. Until that question is resolved, countries will be circling the issue of reducing emissions without addressing the core challenge.
Technological changes are in their early stages, as in how to bury carbon in massive quantities, how to manufacture cost-competitive cars that run on something other than gasoline. The international framework does not exist, because the previous Kyoto Protocol did not include major countries, and some of those that did sign Kyoto broke their promises with impunity and apparently no shame; to wit, Canada.
Above all, the negotiations involved all the countries of the world, from fragile, tiny island states whose very existence will be threatened by 2050 to the two leading emitters - the United States and China - and countries of every size, standard of living, geography and political system in between.
Finding common ground among them was always going to be supremely difficult, and it remains so in the months, perhaps years, ahead as countries struggle to do better than they managed at Copenhagen, where they avoided the worst but did not achieve the best.
The negotiations did underscore the emergence of the world's new power structure, since the critical negotiations involved the United States, China, India and Brazil, with the European Union off to one side, and Canada off the stage completely.
It took a major effort by President Barack Obama to save the negotiations; it will take an even larger one for him to persuade his Congress and the U.S. public to do something serious about climate change. But a Canadian could only admire his moral passion for the issue and his determination to lead, in contrast to the Canadian government's approach that, appropriately enough, earned the country "Fossil of the Year" award by environmental groups at the conference.
Prime Minister Stephen Harper did get two things he wanted from the broad deal at Copenhagen. He had persistently and correctly argued that any new deal had to involve all countries, including the up-and-coming economic powers whose emissions are rising fast. And he had insisted Canada would follow along with whatever the United States decided.
This follow-the-U.S. approach will very likely mean that his government's target of a 20-per-cent reduction by 2020 from a 2006 starting point - a target that almost no one believes will be achieved anyway - can be diluted when the U.S. congressional system lowers the 17-per-cent target contained in a House of Representatives bill.
In other words, the government has given itself splendid political cover for a retreat from the targets it has held aloft for so long.