Stop buying means not turning on the heater in winter… so go back to hearth and fireplace for heat to combat… pollution?
And nuclear energy, while having no carbon emissions, has the problem that nobody wants it in their backyard. Plus, huge upfront investments and costs.
Where? And how?
>>using alternatives, such as green gas
You mean synthetic gas? There is absolutely no capacity to produce anywhere near enough to satisfy even a single percent of European needs.
>>or heat pumps
Heat pumps are not a universal solution, they don't work in all climates, or they require digging trenches or wells to actually be efficient - again, not possible everywhere and for everyone.
And even if it was - with what money? Where I'm from in Poland I know lots of people who still heat their houses with coal, purely because gas is too expensive as it is. And you want to switch their source of heat to an even more expensive one? I'm sure they will be super happy to do that, sure.
You only need as much gas as is required to fill the gap that alternative gas providers and heat pumps can't provide to compensate the lost gas.
Another option is to improve the houses such they leak much less heat.
Money allocation could be managed through a variety of ways, such as EU funds
https://www.theguardian.com/environment/2021/may/07/fireplac...
Politicians tend to make delusional promises which can never happen. Something like this is a long term thing it’s not… stop using gas now!
Governments are trying hard to artificially keep the prices low, but the reality is that the market really really wants people to give up on fossil fuels.
I mean electric boilers, heating panels, ranges and car chargers will easily increase peak loads by 15-25 kilowatts per house, that's 2-4x as much as they currently pull. Do that times hundreds of thousands of houses and you see the issue.
The right conclusion is that now they need to buff up the power grid extremely quickly TOO (it needs not take such a long time, some choices like solar or wind are quite quick to install).
Both the consumer endpoints and production endpoints have to change, of course.
As for the billions required for the transition, since when absolute figures make for good decisions? What is required is a comparison with alternatives. And one sure thing is that the cost of a failed transition, of a climate catastrophe, or indirect consequences like wars, are tremendously more expensive.