a vast improvement in the lives of a huge number of people. It sounds like you view utility of happiness as additive, in which case the only justifiable decisi

a vast improvement in the lives of a huge number of people. It sounds like you view utility of happiness as additive, in which case the only justifiable decision in your unlikely circumstance would be to do everything in your power to prevent the 19th/20th century population explosion that resulted in the need for the aforementioned activities that resulted in climate change. Additively, there's far more misery and suffering in the world now than there has ever been at any point in history.