California’s Air Resources Board (CARB) released a statement saying the state will transition to 100 percent zero-emission busses for its public fleets by 2040.

According to reports, the state currently has 153 zero-emission busses as part of its various fleets, with the goal of having more than 1,000 by the end of 2020. The Innovative Clean Transit would aim to replace 12,000 diesel busses currently in service throughout the state. The regulation will require all busses purchased after 2029 to be electric.

According to a press release by CARB, the initiative will reduce greenhouse gas emissions by 19 million metric tons from 2020 to 2050. They also claim transit agencies in the state would save $1.5 billion in maintenance and fuel costs.