[PhDuck]

I'm not quite sure about the national transportation being 100% green, or at least I misunderstood what you are saying.

As a Dane I can promise you that our governmental public transport is not 100% green, our main long-distance trains (IC3) currently operate on diesel. Neither is the private transport 100% green, since people can buy traditional combustion engine based cars.

[Symbiote]

Indeed, only about a quarter of the Danish rail network is electrified -- quite poor when compared to the neighbours. There's a plan to electrify all the main lines by 2025, according to Wikipedia [1]. I'll be pleased when there's no longer an awful smog on the underground platforms at Nørreport.

DSB publish pollution figures for their fleet: https://www.dsb.dk/om-dsb/samfundsansvar/miljo/fakta-om-milj...

[1] https://en.wikipedia.org/wiki/Rail_transport_in_Denmark