Who is the subject should be instead who the subject is if there is an indirect question. In other words, put the conjugated be form after the subject in indirect questions. If the subject here is the full the subject of global warming and climate change, then it may be better actually to move the is all the way to after this full length subject: I want to know who the subject of global warming and climate change is ...
... climate change whether developed or the developing countries? needs work to become correct: ... climate change, whether in developed or developing countries. Basically, there needs to be a comma after climate change, the two complements of whether need to have the same form (both using the article the, or neither using the), the word in needs to be added after whether, and there should not be a question mark since the question is indirect.
Finally, Are the rich or the poor? needs some work as well to be fully clear. One option is to use the singular is instead of the plural are, which follows from the idea that there is an implied dichotomy in your question, where only one option is possible as the answer. In this approach, the result could be Is it the rich or the poor?. If the word it is undesirable here, the word subject could be used in its place: Is the subject the rich or the poor?. Another approach is to make it clearer that two options are being contrasted. One way to do this is to separate the options into individual sentences: Are the rich? Or are the poor?.
