The EU decided to declare gas along with nuclear to be green. It's easy to see why one might see nuclear energy as a green energy source, it's harder to see the case for gas.
As I previously pointed out, we currently have days in Germany where energy is free and companies can get paid to use up energy. The continuously lowering cost of solar power suggests that those days will increase. Rolling out enough solar and wind to be able to power everything on most days means massive overproduction in electricity on summer days that can be used for applications that need a lot of cheap energy but that are okay with only running when energy production is high. One option for using the energy is to turn CO2 into Synthetic Natural Gas (SNG):
The overall efficiency of energy storage and reuse (power-to-power) is quite high. In the case of SNG synthesis, the energy stored in methane accounts for 53.2% of the input energy. The maximum recoverable energy in the form of heat and electricity is 37.3%
If we predict a future where we will use surplus solar energy to produce SNG, it today makes sense to build gas plants to provide us with energy on winter days with little wind. It’s building plants that will actually provide green energy in the future, which justifies seeing them as green in the EU energy plan.
It also suggests that moving a huge sector like shipping to using natural gas is a valid strategy for making the sector completely green.