Since the beginning of SCI Energy Group’s blog series, new legislation has come into place regarding emission targets. Instead of the previous 80% reduction target, the UK must now achieve net-zero emissions by 2050. This makes significant, rapid emission reduction even more critical. This article introduces the main sources of UK CO2 emissions across individual sectors.

The Big Picture

In 2018, UK CO2 emissions totalled to roughly 364 million tonnes. This was 2.4% lower than 2017 and 43.5% lower than 1990. The image below shows how much each individual sector contributed to the total UK carbon dioxide emissions in 2018. As can be seen, large emitting sectors include: energy supply, transport and residential. For this reason, CO2 emission trends from these sectors are discussed in this article.

 Total UK Greenhouse Gas Emissions per Sector graph

Figure 1 Shows the percentage contribution toward Total UK Greenhouse Gas Emissions per Sector (2018) Figure: BEIS. Contains public sector information licensed under the Open Government Licence v1.0.      

Transport Sector

In 2018, the transport sector accounted for 1/3rd of total UK CO2 emissions. Since 1990, there has been relatively little change in the level of greenhouse gas emissions from this sector. Historically, transport has been the second most-emitting sector. However, due to emission reductions in the energy supply sector, it is now the biggest emitting sector and has been since 2016. Emission sources include road transport, railways, domestic aviation, shipping, fishing & aircraft support vehicles.

cars on motorway gif

Originally posted by fuzzyghost

The main source of emissions are petrol and diesel in road transport. 

Ultra-low emission vehicles (ULEV) can provide emission reductions in this sector. Some examples of these include: hybrid electric, battery electric and hydrogen fuel cell vehicles. In 2018, there were 200,000 ULEV’s on the road in the UK. In addition to this, there was a 53% increase in ULEV vehicle registration compared to 2016. In 2018, UK government released the ‘Road to Zero Strategy’, which seeks to see 50% of new cars to be ULEV’s by 2030 and 40% of new vans.

 electric vehicle charging

Energy Supply Sector

In the past, the energy supply sector was the biggest emitting sector but, since 1990, this sector has reduced its greenhouse gas emissions by 60% making it the second-biggest emitting sector. Between 2017 and 2018, this sector accounted for the largest decrease in CO2 emissions (7.2%). Emission sources included fuel combustion for electricity generation and other energy production sources, The main sources of emission are use of natural gas and coal in power plants.  


Originally posted by konczakowski

In 2015, the Carbon Price Floor tax changed from £9/tonne CO2 emitted to £18/ tonne CO2 emitted. This resulted in a shift from coal to natural gas use for power generation. There has also been a considerable growth in low-carbon technologies for power generation. All of these have contributed to emission reductions in this sector.

 Natural gas power plant

Figure 2 - Natural gas power plant

Residential Sector

Out of the total greenhouse gas emissions from the residential sector, CO2 emissions account for 96%. Emissions from this sector are heavily influenced by external temperatures. For example, colder temperatures drive higher emissions as more heating is required.

In 2018, this sector accounted for 18% of total UK CO2 emissions. Between 2017 and 2018, there was a 2.8% increase in residential emissions. Overall, emissions from this sector have dropped by 16% since 1990. Emission sources include fuel combustion for heating and cooking, garden machinery and aerosols. The main source of emission are natural gas for heating and cooking. 

Originally posted by butteryplanet


The UK has reduced CO2 emissions by 43.5% since 1990. However, further emission reductions are required to meet net-zero targets. The energy supply sector has reduced emissions by 60% since 1990 but remains the second biggest emitter. In comparison to this, emission reductions in the residential sector are minor. Yet, they are still greater than the transport sector, which has remained relatively static. Each of these sectors require significant emission reduction to aid in meeting new emission targets.

bacon and eggs gif