UCLA students call about 11,000 Uber and Lyft rides that never leave campus every week, raising concerns about the environmental impact of unnecessary trips.

Concerns about carbon emissions.

CJ Macklin, a Lyft spokesperson, said "that Lyft has invested hundreds of millions of dollars in carbon offsets, such as renewable energy programs and forestry projects, to cancel out the carbon emissions from their rides."

Doesn't really cancel out in the area receiving the pollution.