The original idea was meant to avoid that. Many of the developed nations expected to contribute some sort of levy or subsidy, and try to help developing nations

The original idea was meant to avoid that. Many of the developed nations expected to contribute some sort of levy or subsidy, and try to help developing nations short cut their way past simply repeating all of our fossil-centric development trajectory. The earliest pre-Kyoto UN talks often seemed to be thinking along those lines. Sadly some nations - especially the US - weren't willing.