The Environmental Protection Agency has warned that Ireland is failing to achieve its obligation to become a low carbon economy.
It said it will not meet its greenhouse gas reductions targets for 2020.
Such an outcome would leave Ireland open to prosecution before the European Court of Justice and ultimately to EU fines.
Even under the best-case scenario, where all relevant policy measures in Government documents are adopted and fully implemented on time, Ireland will not reach the target of cutting its carbon emissions by 20% by 2020.
Carbon emissions result from economic activity, with emissions from agriculture and transportation proving particularly problematic for Ireland.
The EPA said the best possible outcome Ireland can achieve is to bring its emissions down to between 5% and 12% lower than they were in 2005.
EPA Director General Laura Burke said that this challenge will become even more pressing as the economy improves.
She said that Ireland must invest in structural and behavioural change to achieve a carbon neutral and climate resilient economy.
The changes required include the rapid decarbonisation of its energy and transport systems, and the adoption of sustainable food production, management and consumption systems.