The D.C. Council is debating how to spur many of the District’s 7,500 licensed cab drivers to replace their gas-guzzling taxis with more environmentally friendly hybrids, though the city is not expected to establish a costly mandate.

On the heels of a report that the Washington area outpaces the nation in producing greenhouse gas emissions, seven council members Tuesday co-introduced legislation to nudge the District’s cab drivers toward hybrids.