Finland's carbon sinks
Forests constitute a significant carbon sink in Finland. The degree to which carbon is captured in plants increases with global warming but coniferous forests can also change from carbon sinks to carbon sources.
Carbon continuously circulates between the carbon storages across the world. It is estimated that 45% of the carbon dioxide, which the mankind has produced since the 1700s, has remained in the atmosphere, 30% has ended up in the oceans and the remaining 25% is found in plants and soil .
Forests are Finland's most important carbon sink
Forest is Finland's most important carbon sink . In 2007, 33 million tonnes of carbon was captured in their plant biomass as carbon dioxide equivalents (CO2 eqv) . 3.3 million tonnes was captured in the mulch layer and 3.6 million tonnes in mineral wooded soil. On the other hand, organic wooded soil constitutes a relatively large source of emissions: 6.7 million tonnes in 2007. Nitrogen fertilisers used in forests and the burning of biomass also cause some carbon dioxide emissions .
The net carbon sink effect of the LULUCF sector (land use, land-use change and forestry) accounted for 35.4 million tonnes of CO2 eqv (Figure 1) in 2008 . This corresponded to some 50% of Finland's greenhouses gas emissions that year.
Table 1. The LULUCF sector emissions and removals in the years 1990–2008. Emissions and removals as million carbon dioxide tonnes (CO2 eqv) correspondingly (a plus sign indicates removals, while a minus sign indicates emissions). 
Will forests continue to serve as carbon sinks?
Forest flora acts as a carbon sink when the annual increase in the growing stock exceeds the fellings. The cubic capacity of Finland's growing stock has been increasing continuously since 1990 due to the large proportion of young forest, more sustainable forest management and the drainage measures that were carried out earlier . This is also reflected in the growth of the carbon sink, as illustrated in Table 1.
With global warming, the volume of carbon absorbed by plants will increase in Finland. However, carbon captured in forests will be largely stored in the mulch layer and soil in the long term, meaning that the increase in forest flora will be unlikely to be sufficient to replace the carbon dioxide emissions released by soil. In consequence, coniferous forests can change from carbon sinks to carbon sources.
- IPCC. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 p. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html
- Finland’s Fifth National Communication under the United Nations Framework Convention on Climate Change. 2009. Ministry of the Environment and Statistics Finland, Helsinki. http://unfccc.int/resource/docs/natc/fin_nc5.pdf
- Berghäll, O., Ahonen, H.-M., Sinivuori, K. & Snäkin, J.-P. 2003. Kioton pöytäkirjan toimeenpanon säännöt. (Kyoto Protocol and its operational rules. Abstract in English.) Ympäristöministeriö, Helsinki. Suomen ympäristö 607, ympäristönsuojelu. 78 s. http://www.ymparisto.fi/default.asp?contentid=31877&lan=fi
- Statistics Finland: Greenhouse gas inventory http://tilastokeskus.fi/tup/khkinv/index_en.html