Nontherapeutic enhancement isn't just a private choice. It's a global ecological lever. If enhancement becomes a market, it fuels a positional arms race. Richer nations and individuals consume more energy, materials, and medical resources to gain advantages, while the planet already overshoots. Healthcare emits around 4 to 5 percent of global greenhouse gases, and elective enhancements would add demand without treating disease. And a global ban is the only fair way to stop a two tier species split, because patchwork rules just offshore the labs. We can't claim sustainability while engineering luxury upgrades. Ban it.