Global shift to mass transit could save more than $100 trillion and 1,700 megatons of CO2

UC Davis News & Information: "Currently the world leader in urban passenger transportation CO2 emissions, the U.S. is projected to lower these emissions from 670 megatons annually to 560 megatons by 2050 because of slowing travel growth combined with sharp improvements in fuel efficiencies. But a high shift to more sustainable transportation options, along with fewer and shorter car trips related to communication technologies substituting for transportation, could further drop those emissions to about 280 megatons.  "