LIMA, Peru — U.N. global warming talks head into their last scheduled day Friday with rich and poor countries arguing over what kind of climate action plans they should present in the run-up to a key summit in Paris next year.

In a brief visit to the slow-moving negotiations in Lima, U.S. Secretary of State John Kerry urged governments to stop bickering over who should do what to rein in the carbon pollution blamed for heating the planet.

“Pretty simple, folks: It’s everyone’s responsibility, because it’s the net amount of carbon that matters, not each country’s share,” Kerry said Thursday.

He warned that neglecting to forge an effective plan to fight climate change would be judged a “massive, collective moral failure of historical consequences.”

“If we don’t lead, future generations will not forgive us,” Kerry said. “They will want to know how we together could possibly have been so blind, so ideological, so dysfunctional and, frankly, so stubborn” by failing to act on overwhelming scientific evidence.