(a) China and India are doing the best they can, as highlighted by several links in this thread. I don't know where you get this information that China and India are "doing nothing". Please share your source. (b) "I say let it happen", "No one is going to take it seriously until its to late anyway ". Do you see the irony?

Do you have any number to show that developed nations cannot put a dent on global warming? Whatever I could gather in 5 minutes points otherwise [1]. Even if you believe so, they can still help by: (i) Using their technical expertise and money in helping developing countries develop and deploy green technology. (ii) They are the consumers of most of the manufacturing output. They can set stricter rules on ecological impact of produced goods. They can set local laws that will not allow companies to buy from polluting industries.

[1] https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...