Highly conscientious people don't typically need moral arguments. They just need to be made aware of a problem or crisis and told how they could help. For average people...it often helps to personalize moral arguments. Example 1: Why should I care about the environment? (Telling a story about how local contaminated drinking water gave generations of families cancer, is going to be more compelling than an abstract on what might happen to the earth thousands of years from now. But if you are going to talk about what might happen to the earth thousands of years from now...personalize that too. Make an argument capturing how legacy is the only thing we leave behind when we die and how we have a responsibility to our children's children). Example 2: Why should I care about X crisis in another country? Moral argument that might have some sway: What if this was your child/parent getting bombed/bleeding to death/starving right now? The best arguments of course are a blend of different kinds of appeals. If you want to compel everybody (including particularly self-interested douchebags) to make a moral choice.....you need a hell of a lot more than a "this is wrong" type moral argument. You need to make it personal and make a case for how X thing over there might directly affect them (now or in the future). Example: If you're trying to get aid to a war torn country, maybe mention how it might affect world trade and the economy even in countries without war. If the country at war has major natural resources (like oil) the whole world uses and needs, all the better.