CO₂ Emissions

Greenhouse gas emissions come from many different sources. The two most important from the point of view of human contribution to climate change are carbon dioxide (CO₂) and methane (CH₄). Carbon dioxide mainly comes from the combustion of fossil fuels for energy. In Ireland methane mostly comes from agriculture livestock. Other sources of greenhouse gas emissions include industrial processes such as cement manufacture, fertiliser spreading in agriculture and refrigeration gases. CO₂ from burning fossil fuels accounted for just under 60% of all greenhouse gas emissions in Ireland in 2017.

Emissions from large companies (ETS)

Any company or body within the EU that emits a large amount of greenhouse gas emissions is included in the Emissions Trading System, commonly known as the ETS for short. This includes large industries, electricity generators, and the aviation industry. The ETS ensures that all these companies will collectively reduce their emissions by 21% by 2020 compared to 2005.

EU ETS

Emissions from homes, small businesses and farms (Non-ETS)

All greenhouse gas emissions that are not from companies in the ETS are called non-ETS emissions. Non-ETS emissions include greenhouse gas emissions from homes, cars, small businesses and agriculture. These are often collectively called the non-ETS sector.

Non-ETS emissions are important because each country in the EU has mandatory targets to reduce non-ETS emissions in 2020 and 2030. Ireland's target for 2020 is for non-ETS emissions to be 20% lower than they were in 2005. Currently we are on track to be just 1% lower.

EU non-ETS emissions targets

Large share of agriculture

The biggest source of greenhouse gas emissions in Ireland is CO₂ emissions from the burning of fossil fuels in the non-ETS sector, for example in homes and cars. These made up 35% of all greenhouse gas emissions in Ireland in 2017, and 49% of all non-ETS greenhouse gas emissions.

Ireland is unusual compared to other EU countries because greenhouse gas emissions from agriculture make up a much larger share of our emissions. In 2017 agriculture was responsible for 33% of all greenhouse gas emissions, and for 46% of all non-ETS greenhouse gas emissions.

Other greenhouse gas emissions in the non-ETS sector, for instance from refrigeration or from landfill gases, made up 4% of all greenhouse gas emissions, or 5% of non-ETS emissions in 2017.

Companies in the ETS were responsible for 28% of Ireland's greenhouse gas emissions In 2017.

Energy-related CO₂ emissions

SEAI compiles statistics on energy use, which allows us to calculate the amount of carbon dioxide that is released when these fossil fuels are burned. The following sections give more information on carbon dioxide emissions from energy use in Ireland.

The Environmental Protection Agency compiles data on all greenhouse gas emissions for Ireland, including agriculture and industrial processes, more information can be found on the EPA website.

Some fuels emit more CO₂ per unit of energy than others. For instance, coal and peat emit high levels of CO₂ per unit of energy used. Natural gas emits much less. Some renewable energy sources emit zero carbon. Therefore, changes in the mix of fuels used over time can increase or reduce emissions.

Over half of all energy-related CO₂ emissions in 2017 were from burning oil products such as petrol and kerosene. Oil is such a large share because transport makes up a very large share of energy use in Ireland and virtually all energy used for transport is from oil. Most Irish homes also use oil for heating, which is unusual compared to other EU countries.

Coal and peat were responsible for about 20% of all energy-related CO₂ emissions in 2017, mostly from electricity generation.

Intensity of energy emissions

In 2016, the CO₂ emissions intensity of our energy supply was 32% higher than the European average. This was in part due to greater use of high-carbon fuels including coal, peat and oil in Ireland.

Some countries in Europe also have a considerably higher share of renewable energy in their energy mix. For example, hydro contributes a significant share to Norway and Austria’s energy mix. Other reasons include the prevalence of nuclear energy in many European countries (e.g. France), and the widespread use of district heating in many Nordic countries.

Renewable energy to avoid emissions

Using renewable energy for heat, electricity and transport reduced emissions by 4.2 million tonnes CO₂ (MtCO₂) in 2017. This equivalent to the CO₂ emissions of almost three quarters of private cars (1.4 million) on the road. It is also the same as one fifth of agricultural emissions of greenhouse gases.

High emissions from transport

Transport is by far the largest source of energy-related CO₂ emissions in Ireland. In 2017 it was responsible for 39%. It is also the sector where CO₂ emissions are growing the fastest.

The residential and industry sectors are the next biggest sources of energy-related CO₂ emissions. The residential sector was responsible for 24% of energy related CO₂ emissions in 2017 and industry for 21%.

Ireland is unusual in that households emits more CO₂ than industry. This is because Ireland does not have as much heavy industry, such as steel or fertiliser manufacture, compared to other countries. Also we use larger amounts of carbon intensive fuels such as coal, peat and oil in our homes, compared to other EU countries.

Tackling transport emissions crucial for Ireland

To tackle climate change, EU countries have agreed to reduce greenhouse gas emissions from the non-ETS sector in each country.

When looking at the non-ETS sector we exclude greenhouse gas emissions from electricity and large companies, as these are counted under the Emissions Trading System. About half of non-ETS emissions are from agriculture and the other half are energy related.

Looking at the energy-related Non-ETS CO₂ emissions, these are dominated by transport, which was responsible for 58% in 2017. The next biggest share was residential at 28%. Because most industry is under the ETS, industry made up just 3% of energy-related non-ETS CO2 emissions.

For Ireland to reduce our non-ETS emissions and meet our targets for 2030, we need to reduce our greenhouse gas emissions from transport and homes, as well as agriculture.

We can also look at energy-related CO₂ emissions split into the three main modes of energy: heat, transport and electricity. In 2017, transport had the largest share of energy-related CO₂ emissions at 38%, with heat next at 32%. Electricity was responsible for 30% of energy-related CO₂ emissions, despite only accounting for 20% of final energy. This is because large amounts of coal and peat are still burned to generate electricity. These fuels have high CO2 intensity and are burned at relatively low efficiencies.

Energy use is usually linked to economic activity. A growing economy leads to more goods being produced, purchased, transported, and more disposable income for people spend on travel or on heating their homes.

GDP is the most commonly used indicator for economic growth but in Ireland GDP can be disproportionately affected by the accounting of large multinationals. An alternative measure of economic activity developed by the Central Statistics Office is modified GNI.

Ireland’s economy grew rapidly from the early 1990s up until the global financial crisis in 2007. Ireland’s economy then contracted sharply between 2007 and 2010, and continued to shrink until 2012. From 2012 it returned to strong growth.

In Ireland, transport is the sector whose energy use is most sensitive to economic growth. Transport experienced the largest reduction in energy use during the recession and the largest growth since 2012. Most of this growth since 2012 has been from private car use.

In other sectors of the Irish economy energy use is not as closely tied to the economy. Ireland’s economy is more based on the services sector than on manufacturing. Unlike most manufacturing, the services sector has lower energy use per unit of value added, and can significantly increase the value of its output without leading to a large increase in energy use.

Between 2011 and 2014 the economy grew, energy use remained flat and energy-related CO₂ emissions fell. When emissions fall while the economy grows this is sometimes called absolute decoupling. Some reasons for this included:

• Record high energy prices
• Increased use of renewable energy technologies
• Higher efficiency vehicles, homes and businesses

Recent emissions trend

In 2015 and 2016, the economy continued to grow. At the same time energy use and associated CO₂ emissions started to rise again, albeit at a slower rate than economic growth. This is sometimes called relative decoupling. Some reasons for this included:

• A fall in energy prices
• Economic growth
• Increased transport demand 

Emissions fell in 2017 primarily due to lower use of coal in electricity generation and increased renewable generation mainly from wind.