Natural gas is not "clean". Moreover, it is well known that the biggest problem with gas is the production of methane during extraction that is MUCH more dangerous than CO2.
Regarding Germany, the switch is temporary (geopolitical), and they still produce less CO2 every year as planned and have a strong CO2 phase-out plan.
Methane has approximately 28x the warming effect of CO2 in those 10 years, and ultimately it breaks down... To CO2 and water. So every ton of CH4 is like 28 tons of CO2 in the medium term, and like 1+ tons of CO2 in the long term (since water vapor is also a GHG).
It's still CO2 emissions at the end of the day. The issue is nuclear power is right there as the better option. At the end of the day natural gas is still liberating carbon which was locked away and won't be put back anytime soon.
Regarding Germany, the switch is temporary (geopolitical), and they still produce less CO2 every year as planned and have a strong CO2 phase-out plan.