The twin ports of Los Angeles and Long Beach are the busiest in the nation. They also have some of the dirtiest air, thanks to thousands of cargo trucks that pass through each day.
But this month marks the beginning of a new era, as tighter emissions standards go into effect.
'100 Percent Clean Energy'
A common trope in environmental stories is to put things in terms of jobs vs. the environment. But that's not what happened in the case of the ports.
