Consider this. In the UK, it is often much cheaper to fly somewhere than to use a train. For example, London to Newquay, by train will be £150-£200 and by air, about £50. There are countless examples of this.

Airlines are not paying for the pollution they are causing (they should be having to add the price of co2 removal to the ticket prices), whilst trains are too expensive. Individuals will choose using price and convenience. Individuals cannot change big picture issues this. Governments can. Governments have to lead with smart policy and also motivate citizens to do their part where they can.