As stated above, it's for CO2 reduction.
It is also good to note that natural gas is methane, CH4, with just one carbon atom per molecule. It's BTU content vs CO2 production numbers are favorable. About 1/2 that of coal, per BTU and about 1/3 that of coal per KWH.
Solar and wind are incapable of doing the job we need done, even if batteries were up to the task. There is already backroom talk of nuclear acceptance among the group that shuns nukes!
Fuel to power plant, to transformers, to high tension lines, to transformers, to power meter, to charger, to battery, from battery, to controller to motor to wheel. That's a stack of epic losses, and it's forbidden to mention them in any EV publications today. It's why the EV "facts" use watt-hours-per-mile measured at the controller, as that is very favorable. But it has little in common with how much fuel was consumed to generate the power used to charge the EV.
Same goes for electrical costs. They regularly publish 10 cents per KWH as the rate. But those of us who pay electric bills know the total bill includes taxes, fees and charges that can double the cost. It's utter NONSENSE to quote the KWH rate and ignore the rest.
Charge your EV with the most efficient portable inverter generator and get 12 to 19 MPG.