Currently, the richest 10% are responsible for half of all CO2 emissions [1], and you only need $93k be in the richest 10% [2], quite modest by HN standards. Historically, the only way countries have been able to lift themselves out of poverty is by burning fossil fuels for energy. While alternative energy is rapidly advancing, Nigeria isn't going to wait decades to build a solar plant when they can build several coal power plants right now.
[1] https://www.theguardian.com/environment/2015/dec/02/worlds-r...
[2] https://www.cnbc.com/2018/11/07/how-much-money-you-need-to-b...