UK CO₂ emissions on steady downward trend

UK emissions of carbon dioxide (CO₂) fell 3.9% in 2019 to 351.5 million tons, according to provisional statistics published by the Department of Business, Energy and Industrial Strategy (BEIS) in March, leaving CO₂ emissions 41.0% below 1990 levels. In 2019, CO₂ made up 80.8% of all UK greenhouse gas (GHG) emissions, compared with 75.0% in 1990, the data shows.

By far the largest reduction came from the power sector, which slashed its CO₂ emissions by 13.2% last year. This was primarily the result of shifting from coal-fired generation to natural gas alongside increased electricity generation from renewable resources, particularly offshore wind. Power station CO₂ emissions in 2019 were 71.7% lower than in 1990, despite electricity consumption being about 6% higher, according to BEIS.

Coal only accounted for 3% of the fuel used for UK power generation in 2019, compared with 65% in 1990. Low carbon energy sources – renewables and nuclear – have seen their share of the generation mix expand from 22% in 1990 to 48% last year. Total greenhouse gas emissions fell from 451.5 million tons of CO₂ equivalent (MtCO₂e) in 2018 to 435.2 MtCO₂e in 2019, 45.2% lower than in 1990.

Sector weight

The statistics show a remarkable shift in the origin of CO₂ emissions. In 1990, energy supply, which includes power stations, refineries and other energy supply activities, was by far the largest contributor to emissions levels, with a share of 40.6%.

In 2019, that share had dropped to 25.6%. For power stations specifically it fell from 34.1% in 1990 to just 16.3% in 2019. CO₂ emissions from other sectors of the economy have not fallen as fast. As a consequence, transport is now the largest source of CO₂ emissions, with a share of 34.0%, followed by energy supply (25.6%), residential (18.5%) and business (18.4%), according to the provisional data.

CO₂ emissions from transport, which does not include international aviation and shipping, were just 4.6% lower in 2019 than in 1990. The main factor reducing CO₂ emissions from transport is higher levels of vehicle fuel efficiency. The large-scale replacement of coal-fired electricity generation with natural gas means that gas burning now accounts for 54% of CO₂ emissions from fossil fuels in the UK, while coal’s share has plummeted to just 3% and oil’s has risen to 43%. In the power sector, BEIS estimates that emissions from electricity generated by fossil fuels were about 400 tons of CO₂ per GWh in 2019, still higher than the 370 tons of CO₂/GWh that result from using only gas.

The statistics highlight how electrification can help cut CO₂ emissions in sectors where reductions have been lower than in the power sector. Electric vehicles, as oppose to fossil fuel engines, and the use of electricity for cooking and heating, as oppose to natural gas, are powered by the whole generation mix, which BEIS estimates on average emitted 200 tons of CO₂/GWh in 2019.

Covid-19

This year will almost certainly see a further drop in CO₂ emissions as a result both of continued power sector decarbonization and the loss of economic activity, owing to measures needed to contain the coronavirus (Covid-19). Transport emissions, in particular, should fall as non-essential travel is curtailed. In March, the British Chamber of Commerce estimated that GDP growth would slow to just 0.8% this year. Other forecasters suggest the UK economy could enter recession.

During the financial crisis, UK GDP fell by 4.25% and GHG emissions by 8.7%, the largest drop in the last decade, but despite a rebound in 2010 and 2012, emissions continued to fall even as growth returned to positive levels.