UK greenhouse-gas (GHG) emissions in 2009 were 8.7% lower than in 2008 thanks largely to the recession, which saw a significant fall in energy consumption across all sectors of the economy.

The data, from DECC, reveals that UK emissions in 2009 of the basket of six GHGs covered by the Kyoto Protocol – carbon dioxide, methane (CH4), nitrous oxide (N2O), hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride – were estimated to be 566.3 million tonnes CO2 equivalent (mtCO2e). The figure in 2008 was 620.5mtCO2e.

DECC said that the primary reason for the sharp decline in emissions in 2009 was the economic slowdown, which resulted in an overall reduction in demand for electricity, together with lower fossil-fuel consumption by both businesses and households.

“Yes, emissions were down in 2009, but so was the economy, so this is no time for back slapping,” commented energy and climate change secretary Chris Huhne.

A return to economic growth is likely to see emissions rise again.

Between 2008 and 2009 emissions fell in all sectors, with the biggest decrease in industrial processes, where discharges declined by 36.5%.

In other parts of the economy, emissions fell 11% in the energy-supply sector; 11.8% in the business sector; 4.2% in the transport sector; and 5.8% in the residential sector.

GHG emissions from the energy-supply sector in 2009 were 28% lower than in 1990, while the business sector was emitting 24% less in 2009 compared with 1990.

By contrast, residential emissions have reduced only slightly, by around 3%, since 1990, and emissions from transport remain at the same level as 1990.

Emissions of CO2 – which account for 84% of UK GHG discharges – fell further in 2009 than the basket of six GHGs overall, declining by 9.8% compared with the 2008 figure.

Total CO2 discharges in 2009 were 473.7 million tonnes (mt).

In 2008, CO2 emissions totaled 525.1mt. Emissions of CH4 and N2O both fell further in 2009, continuing the recent trend.

CH4 emissions, excluding those from natural sources, were down 2% in 2009 compared with 2008, and have fallen 61% since 1990.

N2O discharges fell a further 5% in 2009 compared with 2008, and have now declined by 49% since 1990.

Methane, weighted by global warming potential, contributed about 8% of the UK’s GHG emissions in 2009, while N2O discharges accounted for 6%.

GHG emissions in the UK by sector: 1990–2009 (mtCO2e)

Sector 1990 2000 2009
Energy supply 272.1 218.6 195.0
Transport 122.1 127.3 122.2
Business 112.4 110.5 85.9
Residential 80.8 90.1 78.6
Agriculture 63.0 57.3 49.5
Waste management 59.0 31.5 17.9
Industrial processes 54.3 24.4 10.4
Public 14.1 11.7 8.2
Land use, land-use change and forestry 3.9 0.4 –4.1
Total 781.6 672 563.6

Source: DECC