Audi is making a new fuel for internal combustion engines that has the potential to make a big dent when it comes to climate change – that's because the synthetic diesel is made from just water and carbon dioxide. The company's pilot plant, which is operated by German startup Sunfire in Dresden, produced its first batches of the "e-diesel" this month. German Federal Minister of Education and Research Johanna Wanka put a few liters of the fuel in her work car, an Audi A8, to commemorate the accomplishment. The base fuel is referred to as "blue crude," and begins by...