The Taoiseach has signalled he will take a tough stance at tonight's EU leaders' summit on setting new targets for carbon emissions up to the year 2030.
Enda Kenny was highly critical of the previous emissions deal, saying: "In Ireland's case we have legacy which is truly catastrophic ... that in my view should have ever have been accepted in the way it was - (a deal) based on per capita income."
He indicated that the current draft deal could not be supported.
Mr Kenny said: "It means that if the language that is currently on the table were to be translated, it would mean that whatever government was in office in 2020 ... would be in a very difficult position."
The Government has been lobbying extensively for special status to be given to Ireland's beef sector, which is responsible for a disproportionate percentage of harmful emissions.
Europe wants to agree ambitious targets ahead of next year's UN climate summit in Paris.
However, environmental groups have warned the targets will be seriously diluted because of conflicting national interests.
Signalling a tough negotiating stance, Mr Kenny said: "I want to make it clear to the European Council that Ireland will be ambitious about our targets, but we do not want to be in a position where completely unreachable targets are set for us.
"That is an issue I intend on argue very strongly because of Ireland's unique position because of our agri-sector."
In 2008, the EU agreed that carbon emissions should be cut by one fifth by 2020, while renewables and energy efficiency increased by 20% by the same date.
With the deadline expiring in six years, the EU wants new targets for 2030 and beyond so it can play a leading role at next year's critical climate change meeting.
However, the debate is set to be tougher this time.
The intervening financial crisis means there has been less investment in green energy, while Russia's involvement in Ukraine has meant that the use of natural gas is not the straightforward, cleaner option it once was.
Ireland has its own concerns as the huge cattle herd means it is already going to miss its 2020 targets, as cows emit methane, which is a much more damaging greenhouse gas than carbon.
Poland, on the other hand, is reliant on coal for 90% of its energy and has threatened to veto the talks if the new targets force it to radically reduce coal consumption without some kind of compensation.
Officials sense a deal can be reached, but the commitment that individual countries have to make in order for Europe to meet its overall target may have to be decided at a later date.
