Is there a viable alternative to using cars?
Yes and no. 100 years ago it was no problem not to have a car and most people didn’t have one or really need one. But since then, since WWII especially, we have been spreading out to the suburbs, distributing ourselves over the land in a way as to make public transportation less efficient and convenient and make a car more of a necessity. We can begin to reverse this process but it didn’t take place in a day and it will take a while to change.
In the meanwhile there are lots of things we can do to cut our energy consumption by half or more. For starters we could stop buying ginormous SUVs and get back into small, efficient cars. We could share cars for commutes. We could begin rebuilding the public transportation infrastructure we destroyed in the 20s, 30s and 40s. We could give people incentives to buy scooters and motorcycles.