update 3pm: In a statement, Ryanair maintained that its passengers had the lowest CO2 emissions per km travelled than any other airline, and directed readers to its environmental policy, which invites customers to offset the carbon cost of their flight by making a voluntary donation to that airline's climate charity partners at the end of the booking process.
Earlier: Ryanair has been ranked as one of the worst carbon emitters among EU companies.
New figures put the airline in the top 10 for the first time, only behind nine coal-producing plants.
Its planes emitted 10 megatonnes of greenhouse gases during 2018.
Andrew Murphy, aviation manager at environment campaign group Transport & Environment, said: “When it comes to climate, Ryanair is the new coal.
“This trend will only continue until Europe realises that this undertaxed and under-regulated sector needs to be brought into line, starting with a tax on kerosene and the introduction of mandates that force airlines to switch to zero-emission jet fuel.
“The worst thing we can do in response is to put all our hopes in an offsetting scheme that gives airlines a license to grow indefinitely. But that is exactly what airlines have cooked up at the industry-dominated UN aviation agency.
“The time has come for a big change in Europe’s aviation policy.”