Tackling the problem from the top-down (regulation) and bottom-up (personal responsibility) is the most effective path forward. The first step is education, actually understanding what contributes to our carbon footprint and more importantly radiative forcing. This gets complicated fast (here's an article on aviation: https://www.theguardian.com/environment/blog/2010/sep/09/car...), but reasonable ballpark estimates can be made.

Transportation accounts for about 14% of emissions, compared to 24% for agriculture and 21% for industry. https://www.epa.gov/ghgemissions/global-greenhouse-gas-emiss...