The notion of how to save the world is different for everone.
One person might want to fight carbon emissions by reducing number of cars. Meanwhile, the other person will want to enable efficient agriculture, by increasing supply of the farm machinery in the short term. Both will be saving the world, while fighting each other.
Everyone thinks they're a good person. Everyone's fighting for somebody else, for a cause or religion or a person or a family member or a legacy or a loved one or something.
One man's terrorist is another man's freedom fighter.
Instead of fighting, build your own garden, clear your own mind, and attend to your own household before you go out and try and fix the world.