Atmospheric carbon dioxide concentrations rose rapidly during the past century, due to fossil fuel combustion and land use change, but can we expect these trends to continue? What concentrations can be expect in the future?

The atmospheric composition scenarios consist of projections of surface ozone concentrations and exposure of vegetation to ozone (developed by FMI-group 2), and global concentrations of carbon dioxide (FMI-group 1).

Summary table

Changes in ground-level ozone and vegetation exposure occurring in Finland, both as observed in the recent decade, and estimated for the period 1900 to 2100, have been studied. A trend analysis of ozone and total nitrate concentrations has been carried out for the 1989-2001 period. Future and past concentrations have been modelled based on chemistry-transport model simulations, the IPCC SRES scenarios and emission inventories.

The ground-level ozone concentrations used in this study were modelled by Tuovinen et al. (2002) using the regional-scale Lagrangian photochemical model of EMEP developed at the Norwegian Meteorological Institute (Simpson 1992, 1995). For these calculations, the European precursor emissions reported for 2010 were scaled for different scenarios according to the data presented in the IPCC SRES report (Nakicenovic and Swart 2000). The methane concentrations and the boundary conditions for ozone concentrations were also derived from the IPCC results (Prather et al. 2001). Simulations of the present-day atmospheric composition use emissions reported by the European countries for 1999 and gridded meteorological input from a numerical weather prediction model for 1994. The model calculations for 2010 use these same meteorological data, while the emissions are taken to follow the reductions agreed in the Gothenburg protocol of the UN ECE (UN/ECE 1999, Vestreng 2001).

Global carbon dioxide (CO₂) concentrations were reported in Houghton et al. (2001, Appendix II.2.1). The CO₂ abundances selected as FINSKEN scenarios have been calculated with the Bern-CC model.

Literature cited

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• Nakicenovic N. & Swart R. (eds.) 2000. Emission Scenarios. Special Report of Working Group III of the Intergovernmental Panel on Climate Change, Cambridge University Press, UK.
• Prather M., Ehhalt D., Dentener F., Derwent R., Dlugokencky E., Holland E., Isaksen I., Katima J., Kirchhoff V., Matson P., Midgley P. & Wang M. 2001. Atmospheric Chemistry and Greenhouse Gases. In: Houghton J.L., Ding Y., Griggs D.J., Noguer M., van der Linden P.J., Dai X., Maskell K. & Johnson C.A. (eds.), Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge and New York, pp. 239-287.
• Simpson D. 1992. Long-period modelling of photochemical oxidants in Europe. Model calculations for July 1995. Atmos. Environ. 26A: 1609-1634.
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• Tuovinen J.-P. 2002. Assessing vegetation exposure to ozone: is it possible to estimate AOT40 by passive sampling? Environ. Pollut. 119: 203-214.
• UN/ECE 1999. Protocol to the 1979 Convention on Long-range Transboundary Air Pollution to Abate Acidification, Eutrophication and Ground-level Ozone. UN/ECE Document EB/AIR/1999/1, United Nations, New York, Geneva.
• Vestreng V. 2001. Emission data reported to UNECE/EMEP: Evaluation of spatial distribution of emissions. EMEP/MSC-W Note 1/01, Norwegian Meteorological Institute, Oslo.