Agriculture emitted 38% of greenhouse gas emissions in 2020, the Central Statistics Office (CSO) has said.
Emissions increased from 32% in 2010.
In all, five sectors accounted for 78% of greenhouse gas emissions in 2020, with agriculture (38%) and households (27%) being the two highest-emitting sectors.
The agriculture sector accounted for 1% of gross value added - the added value generated in an economy by the production of goods and services - and 4% of employment in 2020.
The CSO said that the output of agriculture is an important input for other sectors, for example in 2019, 35% of the value of the output of the agriculture, forestry and fishing sector was used as an input by the food manufacturing sector.
The data shows that in 2020, 96% of greenhouse gas emissions from the agriculture sector were due to agricultural activity, including emissions from livestock.
Emissions due to fuel combustion were 3% of the total, while emissions associated with electricity consumption were a further 1%.
Food and beverage manufacturing made up 3% of emissions in each year between 2010 and 2020.
Around 46% of greenhouse gas emissions by households was from heating, while transport accounted for a further 32% and electricity for another 20% of greenhouse gas emissions in 2020.
The manufacture of cement and other non-metallic minerals accounted for between 4% and 6% of emissions in each year between 2010 and 2020.
Road and other land transport accounted for between 5% and 7% of emissions in each year between 2010 and 2020, while the proportion of electricity generated by renewables increased from 26% in 2015 to 36% in 2021.