Inverse Modelling

With inverse modelling it is possible to trace back the source regions of greenhouse gas emissions

Verification of greenhouse gas emissions using atmospheric observations and inverse 3D atmospheric transport and chemistry models

General concern about increasing atmospheric levels of greenhouse gases has lead to the creation of the United Nations Framework Convention on Climate Change (UNFCCC), which obligates signatory countries to report their annual greenhouse gas emissions (CO2, CH4, N2O, HFCs, PFCs, and SF6), and the Kyoto protocol which sets legally binding emission reduction targets for the so-called Annex-1 parties by 2008-2012. Emissions reported to UNFCCC are based on bottom-up inventories (based on statistical data). However, significant uncertainties remain, in particular for some source categories where emission factors may be highly variable (e.g. CH4 emissions from landfill sites or leakage of natural gas).

Independent verification of greenhouse gas emissions can be provided by atmospheric observations combined with inverse modelling. This approach relates sources (and sinks) of trace gases directly (and in a mathematically optimised way) to the observed atmospheric signal.

At the JRC-IES, an inverse modelling system for atmospheric CH4 is developed, based on the 3D atmospheric zoom model TM5, which allows high resolution simulations e.g. over Europe. Recent results demonstrate the applicability of this technique for verification of CH4 emissions on a national level. In particular, observations and simulations of synoptic variations provide important information about the emissions.

The figure above shows observed and simulated CH4 mixing ratios at a selected monitoring site (Schauinsland, Germany, Observations: Umweltbundesamt). The different colors highlight the contribution of recent emissions from different European countries and global regions.

More information can be found on the Climate Change unit website.

Key references:

Bergamaschi, P., H. Behrend, and A. Jol (ed.) (2004): Inverse modelling of national and EU greenhouse gas emission inventories. Report of the workshop "Inverse modelling for potential verification of national and EU bottom-up GHG inventories" under the mandate of the Monitoring Mechanism Committee WG-1, 23-24 October 2003, JRC, Ispra, pp. 144, EUR 21099 EN / ISBN 92-894-7455-6, European Commission Joint Research Centre, Ispra.

Bergamaschi, P., M. Krol, F. Dentener, A. Vermeulen, F. Meinhardt, R. Graul, M. Ramonet, W. Peters, and E.J. Dlugokencky (2004): Inverse modelling of national and European CH4 emissions using the atmospheric zoom model TM5, Atmospheric Chemistry and Physics, 5, 2431-2460, 2005. Download the file.

EU Legislation and Documents supported by this Action:

• Decision concerning the approval of the Kyoto Prottocol to the UNFCCC and the joint fulfilment of commitments thereunder - 2002/358/EC
• Sixth Community Environment Action Programme

Contact Info:

Peter Bergamaschi - Tel.: +39-0332-789621 E-mail: peter.bergamaschi(at)jrc.ec.europa.eu