Promising advances are being made to reduce the amount of greenhouse gas emissions in natural gas. The most promising is renewable natural gas (RNG), which mostly comes from sources such as dairies and landfills. This biogas is cleaned up and injected into the natural gas system. Unfortunately, there are not enough sources of RNG within California to meet all of our current natural gas needs. However, RNG is a very good solution for interim and hard to electrify applications such as existing buildings, heavy industry and freight.
Another promising resource is hydrogen, which can be injected in small amounts into the natural gas distribution system. The natural gas distribution system can only handle small amounts of hydrogen injection before significant and costly upgrades need to be made.
The bottom line is that there is no way currently make the natural gas system carbon free.