“We found there are four actions that could result in substantial decreases in an individual’s carbon footprint: eating a plant-based diet, avoiding air travel, living car free, and having smaller families. For example, living car-free saves about 2.4 tonnes of CO2 equivalent per year, while eating a plant-based diet saves 0.8 tonnes of CO2 equivalent a year.”
If you can (you know, based on where you live or work), you should give up the car. Just hire one when needed. It’s completely doable.