Case Study 6 mins read

World Accreditation Day 2021 Case Study

Monitoring, reporting and verification of greenhouse gas (GHG) emissions, supported by accreditation of the verification bodies under the IAF MLA.


The European Union Emissions Trading Scheme (EU ETS) is recognised as being one of the most comprehensive and ambitious greenhouse gas emissions monitoring, measurement and reporting programmes in the world.  All emissions reports submitted to the EU ETS must be verified by an organisation that is accredited against the international ISO 14065 standard.  In the UK, this scheme has been replaced by the UK Emissions Trading Scheme, based around the EU ETS requirements.

Similar mandatory requirements for accredited verification are in place for the measurement of CO2 emissions from maritime transport.  UK organisations can also be accredited for verification for various  GHG programmes, ranging from aviation emissions under CORSIA to ensuring compliance with forestry carbon sequestration schemes.

Accreditation plays a crucial role in all of these schemes, as it delivers confidence in the reliability and accuracy of the reported data.  Not only is this fundamental to the success of the individual schemes, it has a significant influence in shaping both government policy and industry ambitions in reducing environmental emissions.


In its most recent assessment report the Intergovernmental Panel on Climate Change (IPCC) advised that by 2050 greenhouse gas (GHG) emissions will need to be between 40-70% of the levels they were in 2010.  The IPCC predicted that failing to reach GHG emissions targets will see average temperatures increase by over two degrees centigrade, leading to drought in some areas, whilst others will suffer heavy rains, storms, landslides, rising sea levels and the erosion of sea shores.

The EU ETS is the cornerstone of the EU’s attempts for reducing man-made GHG emissions.  Running from 2005 to 2020, the EU ETS covered over 50% of all EU emissions across 31 countries.  The EU ETS Phase 4 begins in 2021 and will continue to 2030.

Replacing the UK’s participation in the EU ETS, the UK Emissions Trading Scheme (UK ETS) commenced on 1st January 2021.  It mirrors the EU ETS requirements, and allows operators (both stationary sites and airline operators) emitting large quantities of GHGs to buy and sell allowances in a carbon credit registry.  It therefore rewards operators who reduce their emissions, and penalises those who increase or fail to limit them.


Independent emissions verification is considered good practice by IPCC.  The UK is one of only three countries worldwide (Australia and Switzerland are the others) that currently routinely verify their reported inventory emissions as part of their annual submission to the United Nations Framework Convention on Climate Change (UNFCCC).  The UK has done so for longest and is the only country to do so for all of the principle Kyoto gases.

The UK was instrumental in developing the European Union Emissions Trading Scheme (EU ETS) – it was preceded by and largely based on the UK ETS which started in 2000.  To ensure that UK businesses had continuity of emissions trading following the UK’s decision to withdraw from the EU at the end of 2020, the United Kingdom Emissions Trading Scheme (UK ETS) came into effect at the beginning of 2021.  Based on a “cap and trade” principle, both the EU ETS and UK ETS limits the total amount of carbon that can be emitted each year.  These limits steadily reduce over time, making a significant contribution to meeting the UK government’s NetZero policy target for 2050 and other legally binding commitments.

Under each ETS, heavy energy using installations (such as those in the manufacturing and power generation sectors, as well as aviation operators) are required to monitor and report their emissions each year.  In turn, these reports must be checked by a verifier who is UKAS accredited against the internationally recognised standard ISO 14065.  Businesses in other sectors that wish to participate in voluntary emissions trading and public reporting schemes using ISO 14064-1 for inventories and ISO 14064-2 for projects can also have those reports verified by an organisation that is accredited to ISO 14065.

The details of the verification methodology are contained in ISO 14064-3, which is normatively referenced in ISO 14065).

In 2015 the European Commission reported that Maritime Transport produces about 940 million tonnes of CO2 annually.  This accounts for around 13% of EU GHG emissions from the transport sector, equating to approximately 2.5% of global GHG emissions.  Since 1st January 2018, all ships over 5,000 tonnage unloading/loading cargo or passengers at European Economic Area ports have had to monitor and report their related CO2 emissions.  Similar to the provisions of the EU ETS and UK ETS, all organisations verifying CO2 emissions from maritime transport need to be accredited to ISO 14065.   The EU scheme has also been replaced in the UK by a UK scheme, mirroring the EU one.

UKAS accreditation to ISO 14065 (including ISO 14064-3) provides an independent and authoritative declaration that the organisation carrying out the emissions monitoring has the people, facilities, equipment, technical expertise, management systems and track record to undertake the activity impartially, consistently and competently.  This generates a world of confidence that emissions monitoring and verification reports are accurate and can be relied upon for the important role they play in managing GHG emissions.

The same benefits can be derived by participants in similar UKAS accredited carbon measurement schemes, such as the ICAO Carbon Offsetting and Reporting Scheme for International Aviation (CORSIA), PAS 2050 “carbon footprinting” for goods and services and verification under the Green Gas Trading Limited Biomethane Certification scheme.  The “accredited once, accepted everywhere” approach embodied in the ILAC/IAF MRA/MLA helps internationally-facing users of accredited services avoid repeated assessments, reducing barriers to trade.

Results and Impact

In 2020 the US National Center for Biotechnology Information reported that the EU ETS saved approximately 1.2 billion tons of carbon dioxide emissions between 2008 and 2016, accounting for nearly 4% of total EU-wide emissions. ( )  This was contrary to the widely held perception that the prices set by carbon markets are too low relative to the social cost of carbon.

As the UK’s National Accreditation Body, UKAS began assessments of emissions verification bodies to ISO 14065 for Phase III of the EU-ETS programme in 2012.  Prior to the publication of ISO 14065, UKAS accreditation for the earlier UK scheme and the EU ETS in its early days was done in accordance with EN 45011, the standard for product certification, now superseded by ISO/IEC 17065.

To date, UKAS has accredited 12 organisations providing verification and validation under ISO 14065, including:

9 for regulated schemes (EU/UK ETS);

4 for CORSIA;

6 for voluntary schemes against ISO 14064-1; 2 for the assessment of monitoring plans and verification of emissions reports from maritime transport.

Added to that 4 organisations are participating in a project pilot for demonstrating carbon neutrality under PAS 2060.