Need of the project

Because of VOC contribution to the characterisation of the Earth's climate, the Global Climate Observing System (WMO-GCOS) designated VOCs as essential climate variables (ECVs) in the categories "aerosol and ozone precursors" and "carbon dioxide, methane and other greenhouse gases". Furthermore, the European Air Quality Directive 2008/50/EC regulates VOCs, as well as the directive (NEC) 2001/81/EC, that defines emission ceilings for VOCs. In addition, Halogenated VOCs, such as fluorinated halocarbons are also regulated in the regulation (EU) No 517-2014 and included into the Kigali Amendment of the Montreal Protocol. To control the effectiveness of theses treaties and to assess climate and air quality trends, there is a need for monitoring the amount-of-substance fractions of VOCs.

The WMO-GAW, the European Monitoring and Evaluation Programme (EMEP), research infrastructures (e.g. ACTRIS, AGAGE) and national air pollution networks include these challenging compounds in their long-monitoring programs. Stable traceable references with a low uncertainty − along with well-defined measuring methods − are indispensable for reliable short and long-term measurements of VOCs and for meeting the data quality objectives (DQOs) defined by the monitoring programs. However, despite the significant progress made during the past years, there is still a lack in traceable and stable reference standards for relevant VOCs (e.g. hydrofluoroolefins), as well as in procedures for VOC sampling, calibration, analysis and uncertainty calculation of the measurements.


The project MetClimVOC aims to contribute to meeting the DQOs of monitoring programs, such as ACTRIS, by developing novel, stable and traceable VOC references; improving VOC sampling and analytical methods; establishing guidelines and procedures for the correct sampling, calibration and analysis of selected VOC; disseminating metrological concepts to the monitoring stations (e.g. traceability of working standards, calibration and measurement uncertainty).

The specific objects of the project are grouped in four points.

  1. To develop new primary reference gas standards of relevant VOCs selected in close collaboration with stakeholders (e.g. ACTRIS, WMO-GAW).

  2. To define, select and validate fit-for-purpose protocols for the preparation of SI-traceable working standards. In addition, to calculate the uncertainty budget of each protocol.

  3. To evaluate and improve the sampling and analytical methods for the selected VOCs, assessing relevant influence parameters and establishing the uncertainty budget of the measurement methods. Moreover, to provide SI-traceable spectral parameter for spectroscopic techniques used in remote sensing methods to assess VOCs.

  4. To facilitate the take-up of the technology and measurement infrastructure developed in the project by the measurement supply chain, standards developing organisations and end users.

A detailed description of the specific objectives is available in the project summary.

Long-term impact

Climate change is affecting and will further affect many economic activities leading to economic losses. Human health impacts associated with current air quality and climate change trends are also expected to place additional economic stress on health and social support systems. Furthermore, infrastructure damages from extreme weather events are expected to increase together with the number of victims.

The outputs of MetClimVOC − traceable reference standards, fit-for-purpose working standards and optimised analytical protocols − will result in more accurate and harmonised atmospheric monitoring data that will improve the identification of air quality and climate trends. This improvement will lead to the adoption of more effective mitigation strategies, which will generate long-term economic impact by decreasing the costs related to air pollution and climate change.

Besides the economic and social impacts, the effective mitigation policies will also create environmental impact by limiting the use and emissions of VOCs through more strict legislation and treaties. The future harmonised datasets will additionally lead to a better understanding of long-term global VOC emissions and the chemistry involved by the scientific community, which, in turn, will improve our understanding of other aspects of the global chemistry of the atmosphere (e.g. ozone formation) and its response to anthropogenic emissions. This will help us to adopt effective policies to reduce further anthropogenic impacts on climate.

Moreover, the project outputs will considerably improve the capabilities of European National Metrology Institutes (NMIs) to disseminate traceability for global atmospheric monitoring communities, which will provide the foundation to underpin the work of instrument and standard manufacturers and monitoring networks.

Project duration

The project runs from June 2020 to May 2023.


Thirteen highly complementary partners (national metrology institutes (NMIs), designated institutes (DI), universities and research institutes), that are highly form the consortium.

Some partners (KIT, Empa, IMTelecom, DWD) will be direct end-users of the actual and newly developed services of the project. These partners are part of well-established air monitoring networks (i.e. ACTRIS-topical centre, GAW-world calibration centre) and have responsibility for the traceability, compatibility and labelling of the measurement data. They are forming the future ACTRIS Topical Centre for Reactive Trace Gases In Situ Measurements CiGas. Currently, KIT hosts the World Calibration Centre for VOCs in WMO-GAW.

The end-users and the academic partners also have knowledge about typical on-site problems, such as sampling and/or interference parameters (IL, UU, UoL, POLITO).

Taking a step back, the NMIs (VSL, LNE, METAS, TUBITAK, PTB) are necessary to ensure that these centres can fulfil their role in quality assurance/quality control. These NMIs and the DI (IL) have sound expertise in reference materials/methods and uncertainty assessment. To validate their calibration and measurement capabilities, they compare their SI-traceable methods and analyse the results of each comparison to ensure worldwide comparability, which is independent of the reference type. The traceability chain from primary products (e.g. empty gas cylinders to be used in the gravimetric production of standards) to air monitoring stations is therefore complete within the consortium.


Collaborations are an important aspect of the project, especially to maximise the project impact and to ensure a wide dissemination of the knowledge generated. During the project, partners will contact different companies to offer collaboration, in order to disseminate the project results in the best way and as close as possible to real applications. The consortium is also open to receive collaboration proposals from companies and institutions interested in the project, which can ask for further information using the contact form.


The project has a Stakeholder Committee (SC) integrated by members from organisations which are potential end-users of the project outputs. WMO-GAW, ACTRIS, AGAGE, ICOS and HITRAN among others are some of these organisations. The SC will advise and provide guidance on some of the project deliverables when necessary. The SC will also help the consortium to understand the current needs of end-users and other stakeholders. The involvement of the SC in the project will maximise the knowledge transfer to the measurement stations.

SC members of the project in alphabetical order and their roles; for main affiliation, click on the names:

Chris Boone --- Project Scientist of the Atmospheric Chemistry Experiment (ACE)

Owen Cooper --- Co-chair of the Tropospheric Ozone Assessment Report (TOAR-2)

Yasin Elshorbany --- Lead of the Troposheric Ozone Precursors (TOP) of the (TOAR) focus working group

Iouli Gordon --- Director of the HITRAN spectroscopic database

Lorenzo Labrador --- Scientific officer at the World Meteorological Organization (WMO)

Paolo Laj --- Scientific chair of ACTRIS-Europe and chair of WMO-GAW Scientific Advisory Group for Aerosols (SAG-AERO)

Michela Maione --- Member of the Advanced Global Atmospheric Gases Experiment (AGAGE)

Josep Peñuelas --- Director of CREAF-CEAB-CSIC-UAB Global Ecology Unit

Tuukka Petäjä --- Co-coordinator of the ACTRIS Implementation project

Leonard Rivier --- Director of the Integrated Carbon Observation System Atmosphere Thematic Centre (ICOS-ATC)

Norbert Schmidbauer --- Senior scientist at the Norwegian Institute for Air Research (NILU)

Isobel J. Simpson --- Member of the WMO-GAW Scientific Advisory Group for Reactive Gases (SAG-RG)

Gabriele Stiller --- Head of the Satellite-borne Remote Sensing of Trace Gases Group (SAT) at KIT-IMK, division Atmospheric Trace Gases and Remote Sensing (ASF)

Oksana Tarasova --- Chief of the WMO-Global Atmosphere Watch (GAW) programme

Renato Zenobi --- Head of the Zenobi Group at ETHZ Organic Chemistry Lab