Gas is a fossil fuel that emits carbon when we burn it. Fracking gas is even worse, often making gas dirtier than coal.
Swapping all your gas appliances to electricity saves the average Canberran 824 kilograms carbon per person per year. I've made these calculations based on average ACT usage and the ACT's 100% renewable electricity grid. There are carbon savings in other states too and these will improve as Australia switches off coal-fired electricity and onto renewable electricity.
We don't need gas. You can run your heating, cooking and household appliances on electricity instead. Modern electric appliances are very efficient, particularly reverse-cycle heat pumps. They are cheaper to run, too. Replace end-of-life gas with electricity or consider upgrading even sooner. There are government subsidies in some areas to help.
Combined with my tip on cutting your driving in half by riding a bike, this saves 1.78 tonnes carbon per person per year. If you cut out petrol and diesel cars altogether by swapping to an Electric Vehicle, combined savings are 2.49 tonnes carbon per person per year. Great work!
Notes and data in the 'Notes' section.