In the US legislator, the elected people govern to help their constituents. How does this work with governing for the greater good of everyone. Let’s use climate change as an example and assume it is real and a threat. How should a senator or legislator from “coal country” like Kentucky, vote when it comes to climate change, given the assumptions above? On one hand, and productive climate change mitigation legislation would not be good for coal, so it would be bad for their constituents (at least in the short term). But on the other hand, it would prove beneficial to the world in order to pass climate change mitigation. Is there ever a justification under any political philosophies that you vote for something that will hurt your constituents if it means helping everyone else? Do the founding fathers discuss how to balance this?
The Founding Fathers balanced this by how they set up just who the Constituents of each House were. Originally written the House of Representatives was supposed to represent the interests of the common people in their district, and would vote in their interests. The Senate counter balanced this by being the representatives of the State Government (appointed by election in the states' own legislatures) and would vote for the interests of the State Governments despite the people's will. It wasn't until the 17th Amendment that Senators were directly elected by the people (The initial problem was that states with evenly split legislatures weren't filling vacant seats and would go for periods with one or both seats vacant).
This is the reason for some of the other separation of powers between the two houses, such as the power of the purse, the different term periods (Reps serve for 2 years, Senate for 6) and why the Senate will advise and consent nominations to office by the President but not the House as hold the trials on matters of Impeachment.
This is common practice in many bicameral legislatures around the world, where the lower house represents the people and the upper house represents regional governments of some sort. The United States Model substituted State Appointed Senators, because they modeled congress off of British Parliament, which had the Upper House (House of Lords) seated based off of titles of nobility, which was not something that transferred in a republic government.
One of the purposes of having a legislature with committees is to have robust debates, with a wide range of responsible viewpoints. This mitigates the risk of falsehoods being treated as "givens".
For example, representatives from "coal country" can point out that global warming stopped 22 years ago. (Yes, really.)
But suppose there were a constitutional proposal that would help the United States, but hurt Kentucky. If the proposal really would help the United States on net, then the best possible outcome for Kentucky would be to require the rest of the United States to provide enough benefits to Kentucky that Kentucky is not made worse off by the proposal. The representatives from Kentucky should point out the costs of the proposal, and demand the best possible deal. If the expense of buying off Kentucky (and similar states) was too much to make the proposal worthwhile, then the proposal would probably fail -- and with good reason.
Such vigorous representation helps protect the rights of minorities. Respecting the rights of all minorities ensures that the rights of all people are respected.
Furthermore, all U.S. congressmen have a sworn duty to uphold the U.S. Constitution. If a policy that would help the rest of the world would contradict the U.S. Constitution, they have a sworn duty to oppose that policy.