Ross Greer, the party’s co-leader, said the 31-49 age group was the only one not to be offered a discounted rail fare scheme.
The Scottish Greens have promised a new railcard for millennials paid for by wealthy flyers.
Ross Greer, the party’s co-leader, said the 31-49 age group was the only one not to be offered a discounted rail fare scheme.
Under the Green plans, a “millennial railcard” would save people a third off fares across Scotland.
Read more: Ross Greer: Why the Greens are taking votes from the SNP over climate
Speaking during his keynote speech at the Scottish Green conference, the Greens said their plans would be paid for by a frequent flyer levy.
The party said the policy would target the richest and most frequent flyers and would help limit emissions while supporting Scots taking the bus or train.
According to the Scottish Trades Union Congress (STUC), a tax on frequent flyers could raise around £50 million a year.
The Greens said their plans would include an exemption for lifeline flights to Scotland’s islands.
Mr Greer said: “This weekend we are proposing a Frequent Flyer Levy for those who get the plane like the rest of us get the bus.
“Regular business flights within the UK are literally fuelling climate breakdown.
“They should be paying far more than families going on holiday once a year.
“While bankers fly back and forth between Edinburgh and Canary Wharf multiple times a week, millions of people are working every hour they can get and still struggling to get by.”
Read more: Scottish Green activists push for legal recognition of polyamory
Mr Greer said “a whole generation” of Scots came in adulthood since the financial crash in 2007/2008 have struggled with the basics of life.
He told Green members at Eden Court: “Millennials who too often still can’t afford a deposit for a home, still can’t afford to start a family, still can’t get graduate jobs.
“They are also the only people currently paying full price for their train tickets.
“Everyone else can get a discount or railcard.
“So today I can announce that Green MSPs would use the money from taxing frequent flyers to deliver a millennial railcard, offering one third off train fares for people in their 30s and 40s.”
It is the latest push from the Greens on public transport, with the party playing a key role in the scrapping peak rail fares, rolling out free bus travel to under 22s, and the £2 bus cap in the Highlands.