Current environmental regulations focus exclusively on tailpipe emissions, which are linked to a vehicle's weight. It's true that lowering vehicle weight is important to lowering GHG emissions during the vehicle's driving (or use) phase. But only measuring tailpipe emissions neglects the greenhouse gases created from producing the material in the first place. When we measure C02 emitted during raw material production, it's clear that not all materials are created equally. In fact, steel production emits 5 to 20 times LESS GHG emissions than other material alternatives.