Transportation is a quarter of global emissions, with passenger vehicles making up half of that number and is only getting larger as more people in the world decide they need a car.

The number you're looking for is 20 companies making up 30% of emissions. They're almost exclusively oil companies, with more than half of them being state owned enterprises. Reduce the need for oil and you reduce the amount they pollute.

So, how do you do that?

Personal vehicles are the most flexible in terms of emissions. Increasing the usability of public transportation has a direct correlation with the number of vehicles on the road. Sure, people out in the middle of nowhere need a vehicle and nobody is looking to take that from them, but you could HALF the number of people in the US with a car if cities had proper public transport or were as walkable as they were barely 80 years ago.

The private sector is more difficult. We'd need to rebuild our train infrastructure that has been gutted and raided by our rail companies in order to get trucks off the interstate. Coincidentally, that would get MORE people off the road since you wouldn't need a car to go between cities.

Additionally, you seem to be under the impression that we're incapable of solving multiple problems at the same time. We can make cars unnecessarily (not GET RID of them) while also cutting emissions in other areas.

Make no mistake, we do need to address other areas, but cars are an easy target that would reduce tons of emissions and increase people's quality of life as well. Cars are a massive waste of space and a huge ongoing drain on taxpayer dollars for very little benefit when you compare it to the alternatives.