Depends on how much society is willing to sacrifice. One year isn’t long, but you could conceivably get just about every car and van off diesel, get just about everyone off heating oil (which is just diesel), go crazy on electric trains, dramatically decrease construction and electrify what you can there, and switch backup generators to gas (which doesn’t really help the climate of course but helps with no diesel). The biggest near term issue is likely heavy transit. You could displace some with trains and petrol/electric vans, but there’s going to be serious rationing going on and supply chains will be hanging on by a thread. Farming equipment also a big issue. Hydrogen might be able to start replacing diesel for these uses but within a year is crazy ambitious. This would be hard to do in a decade.

Regardless, we need to approach this from a “war economy” standpoint, so I like the question.

How is it better? It all just evaporates and breaks down into the same amount of CO2, while also poisoning some habitat along the way. I guess it’s less NOx, so maybe that’s a benefit?