TREE COUNCIL OF IRELAND
Comhairle Crann na hÉireann
Carbon Footprint
Calculating Carbon
A simple guide to calculating carbon in a tree
What is a carbon sink?
A carbon sink is a natural system like forests, soil and oceans that store carbon removed from the atmosphere.
How does carbon dioxide enter the atmosphere?
Carbon moves from living things to the atmosphere. Each time you exhale, you are releasing CO2 into the atmosphere. When living things rot away CO2 is also released into the atmosphere.
Carbon moves from fossil fuels into the atmosphere when fuels are burned releasing CO2.
What is bioenergy?
When we use plants and other organic material to generate energy we call it bioenergy.
What is climate change?
Climate change is primarily a problem of too much carbon dioxide (CO2) in the atmosphere.
This carbon overload is caused mainly
when we burn fossil fuels like coal, oil and gas or cut down and burn forests.
Why is an increase of carbon dioxide in the atmosphere so bad?
Its main impact is on a global scale. It is one of the main "greenhouse gases" contributing to climate change.
The heat trapped by CO2 warms our oceans and atmosphere and this is what enables life on Earth.
But excess CO2 can result in our planet becoming too warm thus causing climate change. It can also cause the Greenland ice sheets to melt raising sea levels and impacting life on Earth as we know it.
What is carbon?
When discussing climate change, the basic element of carbon is often mistaken for carbon dioxide. Carbon is the sixth most abundant element on Earth and is essential to life as it is found in all living beings.
At room temperature, it is solid and can be also found in various other forms such as graphite and diamond.
Carbon dioxide (CO2) is the chemical compound. At room temperature, it is gaseous and is vital for life since it plays a major role in photosynthesis.
What is carbon sequestration?
Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide. This helps to either
mitigate or defer dangerous climate change.
Trees and Carbon
Trees take carbon dioxide from the air when their leaves carry out photosynthesis and store it as carbon in the timber, so big trees are carbon sinks.
A ten-year-old evergreen tree absorbs 14 kg of carbon dioxide per year.
Broadleaf trees like our native oak, ash, birch etc grow slower than evergreen trees so it would take more broadleaved trees to achieve the same result.
A broadleaf woodland sequesters carbon more slowly although it may store more carbon long term. It also has more biodiversity.
Fast-growing trees such as Sitka spruce sequester a lot of carbon quickly over a 30-year cycle.
Annual removal of carbon dioxide from the atmosphere by Ireland’s forests exceeds 6 million tonnes per annum.
This works out as a gain of 3.6 million tonnes net of harvesting and planting.
It takes 178 evergreen trees to absorb 2.5 tonnes of carbon dioxide.
Both types of tree planting, i.e. broadleaf and evergreen very much have their place in Ireland depending on which is appropriate to the area being planted.
Carbon Footprint
Burning petrol or diesel in our cars emits a shockingly high amount of carbon dioxide. One litre of petrol emits 2.3kg of carbon dioxide into the air while diesel emits 2.64 kg.
This is because the carbon atoms in the fuel unite with oxygen in the atmosphere during the process of combustion and the weight of carbon dioxide emitted is greater than that of the original carbon in the fuel.
The average Irish car drives 18,000 km per year. This requires 810 litres of diesel or 1080 litres of petrol.
This means 2.14 tonnes of carbon dioxide is emitted for diesel cars and 2.5 tonnes of carbon dioxide for petrol cars.
This is equivalent to what it takes 91 evergreen trees such as Sitka spruce that are 10 years old to absorb
in a year.
Air travel emits roughly the same amount of carbon dioxide per person per kilometre as driving a car but of course, the distances travelled are much greater.
A flight from Dublin to New York return is 10,200 km which is 1.275 tonnes of carbon dioxide emitted per person per flight.
Transport had caused most CO2 emissions every year from 2013 to 2019, but fell by 26% in 2020 because of the COVID-19 pandemic.
Its share returned to growth in 2021 making up 34% of energy related CO2 emissions.
The sector that has contributed most to the increase in transport growth since 2012 has been aviation.
Emissions Trading System (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 43% by 2030 compared to 2005.
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 by 2030.
Carbon Facts
11 tonnes of carbon dioxide is equivalent to 3 tonnes of carbon.
Indeed, if we are really serious about slowing climate change, planting trees is only part of the answer.
We should be changing our way of living so that we produce less carbon per capita each year.
Ireland annually emits around 65 million tonnes of carbon dioxide into the atmosphere - on average 12 tonnes per person.
This is the third-highest per capita rate in Europe after Estonia and Luxembourg.
Transport accounted for 34% of energy related CO2 emissions in 2021.
Electricity generation and households are the next biggest sources of energy-related CO2 emissions.
Electricity generation was responsible for 29% of energy related CO2 emissions in 2021 and fuel use in homes was responsible for 19%.
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.
In 2021 economic growth, energy use and energy related CO2 emissions all grew, after falling in 2020 due to the impacts of the COVID-19 pandemic.