Natural gas is a fairly straight forward conversion. Similar to a propane conversion but the tank is high pressure, so you can park in your garage or underground parkades. Yes it has a low Btu value, but high octane rating. And it is readily available and burns quite clean. This would drop total emissions considerably. CO2 is not the climate villain it is made out to be. We are nearing the end of thawing from the iceage, which is the reason for global warming and the consequence of climate change. All this carbon bullshit is an excuse for billionares to pick peoples pockets!