Historically, the primary responsibility for climate change has been borne by advanced economies and their industrialization process. The contribution of poorer countries (the global south) was negligible. The Kyoto Protocol recognizes "common but differentiated responsibilities" in the fight against climate change. Its successor, the Paris Agreement, asked countries to set voluntary emissions targets, but required richer countries to make financial transfers to developing economies to help developing economies catch up (i.e. reduce emissions and adapt to the negative impacts of climate change). The problem. It set a minimum threshold of $100 billion per year for these transfers. It should have been more than 0.7 percent of their national income, which was foreign development aid. (Partha Sen)