Wales does not need an airport, the leader of the Wales Green Party has said.
Anthony Slaughter said the Greens in government would halt Cardiff Airport expansion and tax aviation fuel.
Mr Slaughter said he had not gone as far as calling for the airport's closure, but said contemplating expansion was a "crime against future generations".
The party launched its election campaign in Barry on Monday.
Mr Slaughter is standing for the party in the Vale of Glamorgan, where the Rhoose airport is located.
The party pledges to "restore and revive devastated communities" with "bold, radical policies".
Asked if a Green-led Wales would have an airport, Mr Slaughter told BBC Wales: "I don't think there's a need for one, personally, so no."
Under the party "we definitely wouldn't see any more expansion" at Cardiff Airport, he said.
"It's a crime against future generations to be contemplating that.
"We would immediately put a halt to all expansion, start charging tax and aviation fuel and slowly make a just transition to a time we do not need Cardiff Airport."
Earlier he told Claire Summers on BBC Radio Wales Breakfast he had not gone as far as calling for it to be scrapped.
Mr Slaughter said: "We are against all airport expansion. It is one of the biggest increasing contributors to carbon emissions.
"We have to look at aviation, and we have to also remember that this is also an equality issue," he said. "The vast majority of flights are taken by a very small number of people.
"The aviation industry is heavily, unfairly subsidised - no tax, no VAT on aviation fuel.
"We cannot carry on with business as usual, and we've seen figures, I think, last week - an increase in the sale of private jets in the UK."
Mr Slaughter said he believed the Greens would cut through with voters.
"We are seeing more and more extreme weather events. Climate emergency is very real, people are aware of it. This has to be the climate election," he added.
"Every issue in this election has to be looked at through the lens of the climate emergency.
"That's why we are offering this green, bold vision - our green vision for Wales: an all-encompassing overall view, radical policies which will not only help us meet our decarbonisation targets but transform our lives."
The party's Brexit policy backs a second referendum - offering either the existing deal or remaining in the EU. Mr Slaughter said was confident remain would "very strongly" win a second vote.
Meanwhile it is pitching to revive "devastated communities" that have "long suffered" the effects of an "unjust industrial transition" and austerity agenda.
Mr Slaughter said the Greens' plans would "pay for the transformation we need".
"It's all been costed. I can't give details until we see the manifesto. But it'll be progressive taxation," he said.
"And there's also the buy-back you get from these things - these things bring money in. You reduce air pollution, you increase health, you reduce the burden on the NHS. So over the years there is an investment that comes back."
Mr Slaughter is standing for the Greens in the Vale of Glamorgan - the party has agreed a pro-EU electoral pact with Plaid Cymru and the Liberal Democrats.
Candidates will stand aside for each other in 11 of the 40 constituencies in Wales to increase the chances of a remain-supporting MP being elected.
Under the deal, the Greens will stand aside in the 10 other seats but will be the only one of the three parties standing in the Vale of Glamorgan.
Other candidates standing in the Vale of Glamorgan for the 12 December general election include Alun Cairns for the Conservatives and Belinda Loveluck-Edwards for Labour.
The close of nominations is 14 November.
Russell George, Welsh Conservative economy spokesman, said: "To say that Wales does not need an airport is both short-sighted and narrow minded.
"Not only is Cardiff Airport a national airport and now a major regional hub - including direct flights across Europe, and to the Middle East - but it is also a major employer for south Wales and beyond, and attracts passengers from this region, across Mid-and West Wales, and England."
Labour was also asked for comment.