> The biggest gain would be in how to refine the aluminum without shipping across the world twice. I keep seeing this about "shipping" being a major contributo

> The biggest gain would be in how to refine the aluminum without shipping across the world twice. I keep seeing this about "shipping" being a major contributor to greenhouse emissions but some brief googling shows it's only 2.2%. This seems very little considering how much is shipping across the oceans and compared to electricity generation and ground-based transport. https://ourworldindata.org/grapher/ghg-emissions-by-sector https://ourworldindata.org/grapher/ghg-emissions-by-sector