Western countries can use some of the wealth they made by getting us into this situation in the first place [1] to pay for green energy projects in developing countries, so developing countries can develop without having to go the same massive CO2 emitting route that Western countries took.
[1] CO2 stays in the atmosphere for several hundred years or more. The US is the source of 25% of what is in there now, and the EU-28 another 22%.
Wealth is not gobs of gold that Western countries sit on. Wealth is the ability to produce energy and turn it into creature's comforts, on a massive scale.
There is no development without massive growth in energy consumption. Please point to a single developed country on this Earth that has CO2 emissions per capita smaller than what Paris accords call for, which, depending on the source, is somewhere between 1.5-2.5 CO2 t/year/capita.
To limit emissions all countries must converge to a low energy lifestyle. There is no more developing for poor countries, and there is harsh un-developing for erst rich countries.
[1] CO2 stays in the atmosphere for several hundred years or more. The US is the source of 25% of what is in there now, and the EU-28 another 22%.