What a difference a year makes for climate change activism.

Twelve months ago, thousands of young campaigners worldwide converged on Copenhagen to pitch protests against the global political failure to tackle global warming.

They disrupted summit meetings with non-violent civil disobedience to air demands of climate justice. Scores were arrested. Naomi Klein, the writer and activist, said at the time that it felt as though “progressive tectonic plates are shifting.”

But a year later – with the start of the next big climate-treaty conference in Cancun, Mexico, days away – activists appear to have dramatically changed their emphasis from confrontation to cooperation.

“There are certain times when it’s useful to take a more critical tone and times when it’s useful to take a more collaborative tone,” said Michael Davidson of SustainUS, an all-volunteer climate action group.

The two meetings “are extremely different,” he noted. For one, the eyes of the world were on Copenhagen as 120 heads of state attended, garnering gobs of global media coverage for the summit – and youth-led protests.

But few government heads are expected in Mexico, meaning that a majority of advocates’ influence will be behind the scenes, not in front of the camera.