The decision to sign the European Union reform treaty in Lisbon on Thursday, just a day before EU leaders meet in Brussels, "hardly sends out the right message" about climate change, Taoiseach Bertie Ahern has said.
He was referring to the amount of extra air miles that will be involved for those concerned.
The location of the treaty signing provoked a major row between Portugal, the current holders of the EU presidency and which wants the deal to be known as the Lisbon Treaty, and Belgium, which jealously guards the role of Brussels in EU affairs.
Portugal wanted the EU six-monthly summit held in Lisbon alongside the treaty signature, while Belgium wanted both to be held in Brussels.
Since a compromise could not be found, EU leaders will now travel to Lisbon on Thursday morning, spend less than six hours there, then fly to Brussels for the summit - accumulating a total of about 48,000 air miles.
The Taoiseach told senior EU officials in Dublin yesterday: "We have to concede that from a climate change perspective, the arrangement hardly sends out the right message: this is something that, as leaders, we have to consider more fully in the future."
Mr Ahern said a date for next year's treaty referendum had not yet been decided, nor had the Government decided if it would put the treaty and a constitutional amendment strengthening children's constitutional rights to the public on the same day.
"That has some attractions, but also presents us with timetabling issues ," he said.
"We know that the implications of the Irish debate will reach far beyond our own borders, yet it must be an Irish debate. Many will visit us from abroad to try and shape the outcome," Mr Ahern told EU heads of missions during their meeting in Dublin.
"For some, particularly those opposed to the European Union, it will be a proxy for a national debate that they would wish to have in their own country. This is not especially helpful to us here, but nonetheless may be the reality."
Delivering perhaps an oblique message to other EU states to tread carefully in the coming debate, he said: "Let us also acknowledge that how the public perceives Europe when they walk into the ballot box will be influenced to some degree by how Europe is featuring in the news that day, that week.
"One of the most striking things about the series of referendums we have had over the decades is how the negative arguments remain the same. This particularly applies to the argument that Europe somehow wants to evolve into a military superpower.
"To you, representatives of our partners, that concept may seem far removed from the real world, but however ill-founded, it is a genuine fear for many in Ireland.
"It highlights the need for us to better explain to our public what it is our Union is doing in seeking to spread peace and stability, for example in the western Balkans where the argument for Union support is irrefutable," said the Taoiseach.
