Offshore Industry Thematic Assessment

Impact of emissions from offshore oil and gas exploration and exploitation and mitigation

OSPAR notes that oil and gas extracted from the OSPAR area is a substantial source of greenhouse gases contributing to global warming, climate change and Ocean Acidification . Assessment of the emissions to air associated with the end use of oil and gas extracted from the OSPAR area is, however, not within the remit of OSPAR. This Thematic Assessment focuses on emissions to air from offshore activities in the OSPAR area, which represents a small proportion of the total emissions arising from the use of oil and gas extracted within the area. In offshore activities, CO₂ accounts for the greatest proportion of emissions to air from offshore oil and gas installations. Approximately 29 Mt was emitted in the OSPAR Maritime Area in 2019.

Although atmospheric emissions are not covered by OSPAR measures or harmonised OSPAR measuring methodologies, they are regulated by EU measures or national regulations. Consistency in the quality of the reported offshore oil and gas production emissions data has undoubtedly improved over the past few years, particularly with regard to CO₂ emissions, which are independently verified as part of the EU ETS Directive. A decreasing trend in offshore oil and gas production emissions to the atmosphere was identified over the 2009-2019 period:

• CO₂ emissions decreased by 7,5% between 2009 and 2019, with decreases in most Contracting Parties except Norway;
• NO_x emissions trended downwards by 9,2% from 2009 to 2019, predominantly in Denmark, the Netherlands and Norway, where national measures to control NO_x are in place. United Kingdom emissions remained largely static;
• Methane emissions decreased by 35% in 2009 to 2019 in most Contracting Parties, in particular Norway, the Netherlands and Germany;
• NMVOC emissions decreased by 7,2% in the 2009 to 2019 period, with significant decreases in most Contracting Parties offset by increases in the United Kingdom; and
• SO₂ emissions decreased by 33% between 2009 and 2019, with decreases in Denmark and the Netherlands offset by increases in Norway.

The contribution to CO₂ emissions arising from the exploration and production activities of the offshore oil and gas industry as a proportion of Contracting Parties national emissions varies depending on the size of the oil and gas industry in the Contracting Party¹. For Contracting Parties with a small offshore industry footprint such as Spain, Germany, and Ireland the contribution from oil and gas ranges from 0,001 – 0,2% of total national emissions. For Denmark and the Netherlands, it is an average of 4,9% and 1,1% respectively, while in Norway and the United Kingdom it is 35,5%² and 3,4% respectively.

Measures taken by operators to improve combustion plant efficiency and reduce fugitive emissions (e.g., methane leaks) have contributed towards emissions reduction. However, in interpreting these changes, one must take into account factors which have a direct influence on atmospheric emissions, such as the fact that emissions associated with mature fields would increase due to the greater power demands associated with the use of injection as a method to dispose of produced water and drill cuttings, and the possible use of diesel generation for such activities where there are native fuel gas supply deficits. The decommissioning of ageing installations in the coming years may generate emissions similar to those of production installations. However, following these temporary activities longer-term operational emissions would cease at these locations. 

The future – The World Bank’s ‘Zero Routine Flaring by 2030’ initiative invites governments and industry to end the operational practice of routine flaring during normal production operations by 2030. Denmark, Germany, the Netherlands, Norway, and the United Kingdom have committed to this initiative. Similarly, as the largest proportion of emissions from offshore oil and production stem from power generation, efforts to connect offshore installations to the main grid or renewable power sources are gaining momentum and are expected to further reduce emissions from offshore installations in the next decade.

Risks and consequences from climate change for the offshore industry

Current knowledge indicates that pressures and impacts related to climate change and ocean acidification will intensify markedly. In the North Sea, the water temperature has risen as a result of climate change and changes in ocean circulation, and acidification has been registered. In the Arctic waters, climate change has resulted in long-term trends of rising sea temperatures, shrinking ice coverage and large-scale ecological changes, especially in the northernmost areas.

Some of these climate factors can be expected to affect the offshore oil and gas industry. Reduced ice coverage may result in increased activity in the Arctic due to increased access to Arctic resources as sea ice retreats following the rise in global temperature.

Climate change also presents a changing hazard to offshore infrastructures in the long term. Meteorological and oceanographic conditions that present a risk to offshore infrastructure from climate change include extreme wind, waves, current events, and rising sea level.

The vulnerabilities resulting from extreme storms and high wave events include the destabilisation or degradation of offshore structures, risk to offshore workers, reduced operating periods, damage to pipeline systems due to sediment transport and the prevention of access for maintenance and inspection activities, thereby increasing the likelihood of accidents including pollution incidents.

While design codes for offshore infrastructure have been in place for some time, these are having to evolve to allow for the future effects of climate change on the selection of environmental loads, air gaps beneath structures, and for the effects of other actions on offshore infrastructure.

While shifts in policies towards low carbon economies gain momentum, it is recognised that oil and gas will remain part of the energy mix (albeit declining) for many countries. The risks of unabated emissions from offshore oil and gas production remain in the context of climate change.

Footnotes

¹National CO₂ emission data taken from iea.org

²The relative contribution from the oil and gas industry to Norwegian emissions is high compared to the other OSPAR countries. This is due to oil and gas being the largest industry in Norway and that hydropower is the major source of energy for other industries and households.