A lot of it is out of their control as well as there being a scale issue - for instance if you're a country like Niue which has a population of 1,000 and a tota

A lot of it is out of their control as well as there being a scale issue - for instance if you're a country like Niue which has a population of 1,000 and a total GDP of $10 million and you're thousands of kilometres from the nearest country that gives aid rather than relies on it, then you have limited options with what you can do. Getting goods to the country means it has to come from NZ which is almost 3,000 killometres away, that's a lot of oil for the ships. There's limited ability to use green power as it has a high up front cost and isn't going to be able to provide consistent enough power (relying on wind, or tides, or daylight). It's not economic to ship trash off shore to recycle so it's burnt. Things will change as the west advances, for instance a single wind turbine and batteries could power a country like Niue completely renewably, couple that with solar powered shipping and you start to see a change. But, these countries have very limited natural resources, technical expertise, and are constantly at the mercy of the elements. Any change to make them greener will have to be paid for and be driven from wealthier countries and it makes more sense, environmentally, to spend that money on those wealthier countries where it can go further to reduce more emissions.