Now it looks like the two countries will continue to dominate talks, due to increasingly divergent views on their own responsibilities. On Wednesday, China's lead negotiator at Copenhagen, Su Wei, spoke out on the disagreement at a Beijing climate conference. According to the AFP, Wei told an audience that China "could not and would not" set any limits on its emissions.
The statement wasn't a radical departure from China's stance at Copenhagen, but presents more of a cut-and-dried statement than the country's ruling party has presented at times. At Copenhagen, China suggested it would only set a goal of cutting "carbon intensity", or the emissions produced in its usual activities, by 40 to 45 percent by 2020, which would still allow unlimited growth in total emissions. Now it appears to be trying to set that target in stone.
China's refusal to accept a carbon cap presents a political problem for the U.S., though, which has for years avoided the Kyoto Protocol and other measures in part because voters fear giving developing nations another commercial advantage, in addition to cheap wages. With a carbon cap at home but not abroad, the thinking goes, the remaining emissions-heavy industries would quickly move overseas.
So the U.S. is fighting back, by attempting to set the terms under which negotiations will re-start in Mexico later this year. On the same day as Wei's statement in Beijing, a U.S. document was posted to a United Nations website showing support for the so-called Copenhagen Accord, the non-legally binding treaty worked out at the last minute in December.
That might sound like an uncontentious position, but whether to move forward with the Accord is an important question for Mexico. Under the Accord, the U.S. might be able to argue that China, India and other large developing nations should cap their emissions. But previous agreements -- those that China prefers -- set most of the responsibility for reducing emissions on developed nations like the U.S.
The great fear among environmentalists is that the Mexico conference, like Copenhagen, will fizzle out in diplomatic wrangling. But on the current course, it looks like disagreements will once again be the main show.