Environment Report 2018

3.5. 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; 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

) and

oxides of nitrogen (NO x

) and sulphur (SO x

). Small amounts of nitrous oxide (N 2

O) are also emitted. Releases of

volatile organic compounds (VOCs) and CH 4

may occur during tank loading or from firefighting equipment.

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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 456 million tonnes of CO 2 equivalent (CO 2 e) GHG emissions were emitted in the UK in 2017, representing a 3 per cent fall from 2016 (468 million tonnes CO 2 e). 7 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.

Upstream oil and gas operations contributed 3 per cent (15.7 million tonnes CO 2

e) of total UK GHG emissions in

2017, as shown in Figure 9.

Figure 9: Total Greenhouse Gas Emissions from Upstream Oil and Gas Operations

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20

15

5 GHG Emissions (CO 2 Equivalent Million Tonnes) 10

0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Source: EEMS October 2018

7 Provisional UK greenhouse gas emissions national statistics 2017 are available at https://www.gov.uk/government/statistics/provisional-uk-greenhouse-gas-emissions-national-statistics-2017

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