What is the justification that the proponents of the Kyoto Protocol offer for developing countries having different requirements than developed countries?

the Kyoto protocol justified the diffference in requirements by pointing out that the bulk of the current problems were created by developed countries and so they should make the bigger sacrifices necessary to clean them up

Explanation: the Kyoto protocol is an international treaty extending the 1992 United Nations Framework Convention on Climate Change (UNFCCC) which commits nations to reduce greenhouse gas emissions, based on the fact that global warming is occurring and most likely caused by human-made CO2 emissions.

The common but differentiated responsibilities is as a result of each member nation's abilities,as the developed countries economically developed and they created the bulk of the emissions.