Reuters: The ports of Los Angeles and Long Beach, the busiest U.S. cargo complex, launched a landmark clean-air program on Wednesday banning some 2,000 older trucks blamed for half the pollution spewed by the ports’ diesel haulers. The port complex ranks as the biggest air polluter in Southern California — more than the region’s cars — and heavy-duty trucks operating there generate more than a third of its overall diesel emissions, port officials say. Despite weeks of court wrangling …