Environment Report 2019

3.3 Atmospheric Emissions The extraction, stabilisation and export of hydrocarbons involves several processes that give rise to atmospheric emissions. These include combustion to provide electrical power and drive compressors and pumps, the flaring of excess gas for safety and/or during well testing, tank loading and incidental releases from firefighting and refrigeration equipment.

Combustion and flaring result in emissions of carbon dioxide (CO 2

), carbon monoxide (CO), methane (CH 4 ), O) are also emitted. Releases of

oxides of nitrogen (NO x

) and sulphur (SO x

). Small amounts of nitrous oxide (N 2

volatile organic compounds (VOCs) and CH 4

may occur during tank loading or from firefighting equipment.

3

Upstream Oil and Gas Emissions in a Broader UK Context The Kyoto Protocol defines six greenhouse gases (GHGs) including CO 2 , CH 4 , N 2

O, hydrofluorocarbons (HFCs),

perfluorocarbons (PFCs) and sulphur hexafluoride (SF 6

). GHG emissions stem from various sources and it is widely

accepted that these emissions are contributing to anthropogenic global climate change.

A changing energy supply is helping to decarbonise the UK’s energy mix. Country-wide, an estimated 449 million tonnes of CO 2 e GHG emissions were emitted in the UK in 2018, 2 representing a 2.6 per cent fall from 2017 (460 million tonnes CO 2 e). The reduction largely reflects changes in the power generation sector. The replacement of coal by gas and increased renewable capacity are key drivers and overall have led to a 43 per cent reduction in GHG emissions since 1990. e) of total UK GHG emissions in 2018. A breakdown of the GHG emissions from offshore oil and gas activity is shown in Figure 2. Most of the GHG emissions are from CO 2 and a downward trend is seen from 2000. In recent years CO 2 emissions have stabilised with a small, annual variation of between 1 and 5 per cent year on year, whilst production over the same period has increased by 20 per cent. Upstream oil and gas operations contributed 3 per cent (14.63 million tonnes CO 2

2 Provisional UK greenhouse gas emissions national statistics 2018 are available at assets.publishing.service.gov.uk/ government/uploads/system/uploads/attachment_data/file/790626/2018-provisional-emissions-statistics-report.pdf

11