On the note of ULEZ and EV to save CO2 emission, it doesn't make...

On the note of ULEZ and EV to save CO2 emission, it doesn't make sense and will not make any significant in emissions in global perspective.

Take example of EU as a whole. EU total annual global CO2 emission is 17% of global emissions. And roughly 15% of this annual emission (17%) come from car and light vans which the PM wants to ban by 2030.
15% of 17% is about 2.5%. So even if the EU goes 100% EV by 2030 it will only shave off about 2.5% global emissions. And that is ONLY on the conditions that their grid electricity to charge EV is 100% renewable and fossil fuel free. And having all the critical minerals and infrastructure to support EV.
Apply the same equation to UK and AU, 100% EV does not mean anything in term of global emissions.

Put that in the bigger picture of human emissions is about 3-5% of all sources of CO2 emissions (noting natural seasonal variations of CO2 emissions is about 10%) numbers appear to be even less significant.