My guess is nuclear energy, more efficient cars, better insulated houses, and less heavy industry.
As electricity prices are lowered (e.g. by state investment in nuclear) various things that use fossil fuels will shift over to electric.
1. https://www.cleanenergywire.org/factsheets/heating-40-millio...
2. https://heatpumpingtechnologies.org/annex46/wp-content/uploa...
Unfortunately, that does not exist in nuclear power. As in, not a single one of those requirements is fulfilled by any commercial design.
moving manufacturing overseas
I'm tired of: "The EU doesn't emit as much as China does". Let's account for all the garbage we let China produce and then look at the numbers again.
Which sadly is usually absolutely no controls
At least per the available data from 1990, France has lowered its consumption-based CO₂ emissions in absolute terms:
* https://ourworldindata.org/grapher/consumption-co2-emissions...
And given the population has also risen since 1990:
* https://ourworldindata.org/grapher/population?time=1990..lat...
even if total emissions had stayed the same, per capita numbers would have gone down.
The same if often said of the US, and it is not true either:
* https://www.noahpinion.blog/p/no-the-us-didnt-outsource-our-...
https://ourworldindata.org/co2/country/france
Somehow, from 1973 they went from 10t C02 per capita to 4.8 t per capita in 2022.
Their GDP at the same went from 264 Bn to ~2779 Bn
https://www.macrotrends.net/global-metrics/countries/FRA/fra...
Whatever mysterious method of C02 reduction they used should be investigated.