Voi 5 <1996): 377-385. Potential economic effects of climate change on Finnish agriculture Lauri Kettunen Agricultural Economics Research Institute, P.O. Box 3, FIN-00411 Helsinki In the assessment of the economic effects of climate change, changes in returns and costs have to be taken into consideration. Changes in returns are mainly caused by changes in the yield level. Costs are determined by various factors. Harvesting conditions may improve as the temperatures are high- er. However, an increasing need for disease and pest control results in higher costs. Various extensive studies have indicated that rising temperatures with the C0 2 fertilizing effect increase the crop poten- tial in Finland. From the economic point of view an increase in yield level is highly significant, because the increase in costs remains quite small, A 10% increase in the yield level raises the farm income by about 6%. Because agriculture is supported in many ways either directly or indirectly, the rise in income level may be offset by lowering the support. Consequently, farmers may not benefit from an increase in the yield level, but the benefit will go to the state economy. However, an increase in the yield level resulting from rising temperatures is advantageous to the national economy, regardless of whether the benefit goes to the farmers or to the state. Key words: policy changes, welfare effects Introduction The economic effects of climate change result from consequent changes in the yields of cultured plants. In the case of Finland, recent studies of the SILMU programme (Mela et al. 1996) indicate that crop yields will increase, i.e. the yield function will shift upwards. This has a direct positive effect on the economic result at farm level. However, there are also potential losses due to crop pests and diseases which have to be taken into account. In addition to changes in quantity, economic analysis requires an analysis of changes in the prices of the output and in the costs of produc- tion. Changes in output prices are due to chan- ges in supply, which may be local, regional, or global (Parry et al. 1996). When changes in world food supply are taken into account, the economic analysis becomes quite complicated due to changes in trade flows and policy impli- cations (Rosenzweig and Parry 1994). The SILMU programme has adopted time slice scenarios (years 2020, 2050, and 2100) for the evaluationof the change in crop production © Agricultural and Food Science in Finland Manuscript received February 1996 377 AGRICULTURAL AND FOOD SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=tOnR2M7f9ex0--ow.8yBmXEVbiLj8Ga3oBClSkQ.1spVjFx7eL1RrhwfAHMFFaH8OV0H0SVZ3p9Wkf1Ug-UVL_nTsfMYvwmUMlbE0S9peB9NJj2fhtUt5W62ZAjH1LymJcHQJSjroX2nP3-MN1fnda3q7Oxv-a7iBcCmFYyrsXoj17HELSOwdQNjLaarEXlWyCygLQRFLmuSag2wRMpSDQkxIvqV_mA-CZKize9pS1KXtSMDsL6Bs9OLoDeVf3yKurzg_k82_yiKZha-Ei-1LFkFfn5VjiQR4KWurF2nAh5rtwQ Kettunen, L: Potential economic effects ofclimate change on Finnish agriculture due to climate change. Mean annual tempera- tures will rise 1.1-6.6°C by 2100. Annual pre- cipitation will increase, too (Carter 1996). The study by Mela et al. (1996) indicates the follow- ing effects on crop production for Finland by 2050: - Increased yields of adapted spring cereals, improved potential for the cultivation of high- er-yielding winter sown cereals. - Increased grass yields due to the lengthening growing season. - Increased potential for yield losses due to crop pests and diseases under climate warming. The authors are cautious in giving any quanti- tative estimates of the increased yields and loss- es, which would be necessary for an economic analysis. The aim of this paper is to evaluate the po- tential economic effects of climate change on Finnish agriculture based on the latest studies of the SILMU programme (Mela et al. 1996). Since there are no specific scenarios of the change of yields available, two examples of the economic effects on the farm level are present- ed. They are based on an assumed increase of the yield level and costs by 10%. These results can be easily applied for any specific scenario which may be available after further studies on yield levels. The effect of policy changes due to the altered demand and supply is considered. In addition, some earlier economic analyses are reviewed. Economic analysis Economic analysis has to be done at the farm level (micro level) and at the country level (macro level). At the farm level prices are given and the farmer adjusts production according to the prices of the output and inputs and the endow- ments available. Prices are determined by mar- ket forces and deliberate policy measures of a country (or of the European Union, EU). World market prices influence the national (or EU) pric- es depending on the border protection at the time of consideration. Price changes are caused by changes in supply. Difficulties arise in estimating price changes since the policy framework is going to change within the long time horizon considered. At present the prices in Finland are determined by the Common Agricultural Policy (CAP) of the EU. Prices are regulated, and a change in the world-wide market equilibrium may not affect the internalprices of the EU at all. How- ever, in the long run a change in the overall supply to world markets may significantly affect the pric- es paid to farmers. Micro level The economic effects ofclimate change comprise various factors. The change in the growing con- ditions affects the ability of plants to utilise the carbon dioxide in the air and the nutrients in the soil. In Finland the yield levels of crops are ex- pected to rise as a result of the greenhouse ef- fect. The quantity of production per hectare will increase (Hakala and Mela 1996). Changes will oc- cur in the areas where crops can be cultivated, which alters the production structure (Carter et al. 1996). New high-yielding varieties can be intro- duced inFinland and the optimum level of fertiliz- er use may rise (Kleemola and Karvonen 1996). Consequently, the production potential may increase in two ways: as a result of the increase in yield levels and due to introduction of the new high-yielding varieties. The pasture season is also going to be longer, and thus pastures will produce a higher yield as well. Climate change is not likely to have any dir- ect effects on livestock production. Milk pro- duction is not dependent on temperatures as long as there is adequate protection during the win- ter. Average yields do not rise as a result ofhigher temperatures. Climate change will affect the costs as well. In the first place, changes occur in crop produc- tion. Because of the longer growing period tem- peratures are likely to be higher during harvest- ing. This could result in a decrease in the mois- ture content of harvested cereals and the costs for drying them will decrease. However, it is also 378 AGRICULTURAL AND FOOD SCIENCE IN FINLAND possible that the precipitation increases to the extent that moisture content will not decrease and the drying costs remain at the same level as earlier. Nevertheless, a longer growing season will lower the risks involved in cereal production, especially during harvesting. Being able to go to the fields earlier in the spring usually results in higher yields, but the time of seeding is less likely to be as significant for obtaining a good yield as it is today. It is assumed that rising temperatures will be accompanied by more plant diseases and pests, which is going to increase the costs and slow down the rise in the yield level (Kaukoranta 1996, Carteret al. 1996). The effect of the change in climate condi- tions on the costs of animal husbandry remains small. The pasture season will be longer, which may result in a reduction in fodder cost. Because of the higher temperatures, some savings may be achieved in building costs as more lightly con- structed animal sheds could be adequate, but this may not be very significant (Carter et al. 1992). Macro level The direct macro level effects of climate change are not very significant, and for the most part they are going to result from changes in the mar- ket situation. The greenhouse effect is going to alter the supply of agricultural products. In the present situation the definition of the domestic market is a little complicated. The question is to what extent the Finnish markets operate inde- pendently, or should we always look at the is- sues from the viewpoint of the whole EU. From the standpoint of Finland alone, climate change is going to result in a considerable increase in supply and the price level will drop. At the EU level the changes are going to be relatively small. The effect of climate change is probably going to be positive in the northern countries of Eu- rope, but negative in southern countries, where many scenarios indicate an increase in drought frequency and increased problems of water sup- ply for irrigation (Flarrison et al. 1995). As cereals are easy to transport from one country to another, the impact of the production increase in Finland on the production (and the supply) of the whole EU remains small. This means that the price change would be very small and need not be taken into account at all. In crop production, plant breeding must be adjusted to the new situation. It is difficult to say whether this will cause additionalcosts. It is possible that there will be some increase in re- search costs, but the costs of the actual breeding activity can be considered to remain at the same level as earlier. Thus changes will mainly occur in the allocation of research funds. World level Changes in the agricultural production at the global level influence the world market prices and, through these, the incomes of individual farmers. The study by Rosenzweig and Parry (1994) concludes that the greenhouse effect will lead to a small decrease in global crop production with respect to the base scenario. The decrease is larger in the developing than in the developed countries (Reilly et al. 1994). This will induce a rise in the world market prices from 24 to 145%, depending on the climate scenario (Parry et al. 1996, Fischer et al. 1994). The extent of the reaction depends mainly on how open the world markets are. The baseline assumption of the study by Parry et al. (1996) is that by 2020 there will be a 50% trade liberal- isation. Going towards 2050 or 2100 the markets may be even more liberalised. This means that the price level ofcrops will be much higher than in 1995. The world-wide effect on prices in an- imal production may be smaller, since the mar- kets are more local or regional and the price ef- fects do not spread as effectively as in the case of cereals. Production Yield level The most significant consequence of the green- house effect in Finland is the rise in the yield 379 Vol. 5 (1996): 377-385. AGRICULTURAL AND FOOD SCIENCE IN FINLAND Kettunen, L: Potential economic effects of climate change on Finnish agriculture level. There are no overall estimates of yield in- creases for the whole country and for all crops. Warming alone decreases yields of current cul- tivars in Southern Finland. Combined with C02 increases, yields increase in all regions, the most in Central/Northern Finland, and slightly in the south (Mela et al. 1996). Mukula (1988) and Rantanen (1988) estimated that the yields of spring wheatand barley will increase by 10-20% under a 2xC02 climate change scenario. Higher temperatures make it possible to in- crease the use of fertilizers, which also causes the yield level to rise (Kleemola and Karvonen 1996). However, this option may not be fully uti- lised. The reason for this is that at present a maximum level has been set for fertilizer use, if farmers are to benefit from environmental sup- port. It is also possible that in the future fertiliz- er use will be restricted even more. This means that the yield function rises, but fertilizer use is kept at an earlier level. The adoption of new varieties may also give higher yields. Preliminary estimates for barley yields by 2050 under the SILMU “best guess” scenario of temperature, precipitation, and C02 change, under current N application rates gave yields increases of about 35% at Jokioinen for an adapted variety (compared with 23%for a cur- rent variety). For higher nitrogen application, the increase could be over 40% (Kleemola and Kar- vonen 1996). Pasture season The longer pasture season means higher fodder yields (Mela et al. 1996), but water stress may restrict the increase if the climate dries in sum- mer. This change can be taken into account either in the yield level estimates or the cost cal- culations. Estimating the total yield from pas- tures is usually quite difficult and it is seldom done, even if it would be possible on the ba- sis of e.g. livestock production. Due to vari- ations in weather conditions, annual estimates of the yield of pastures present average figures which do not correspond to the actual amounts. Experiments under high C02 and increased temperatures equivalent to changes towards the end of the next century in Jokioinen and in Apuk- ka, Rovaniemi suggest increases of meadow fes- cue yields over a whole season in the order of 20-100%, depending on the season and location (see Hakala and Mela 1996, Mela et al. 1996). Areas It is very difficult to estimate long-term changes in the distribution of cultivated land. In a sit- uation of free competition the areas under culti- vation would grow along with improvements in profitability and comparative advantage. Under current EU directives, the price policy, especially hectarage support according to the CAP reform (Kettunen and Niemi 1994), determines the max- imum areas for cultivation. It seems that over the very long term (say 50 years) increasing the cereal production in the world will become nec- essary due to global population growth. In this case, the growth of production potential in the north is likely to be utilised in full. However, in this connection it is not possible to take this into account, but we must start from the assumption that the areas under cereals will not grow and the growth in crop production will be based on the increase in yield level alone. The shift of cultivation zones further to the north means, in particular, that the possibilities for the cultivation of cereals are going to im- prove over the whole country. Northward shifts in thermal suitability for cereals are approxim- ately 100-150 km/°C warming or about 50 km per decade up to 2050 under the SILMU “best guess” climate scenario (Mela et al. 1996). Be- cause the total area under cultivation is restricted within the present policy, it will only be pos- sible to change the relative areas of the different crops so that the total area remains the same. In the longer run, however arable land area is like- ly to increase. Production quantities Changes in production concern crop production only. If the areas remain the same, crop produc- 380 AGRICULTURAL AND FOOD SCIENCE IN FINLAND tion will increase in proportion to the increase in the yield level. In this case the change in the value of production can be estimated as an in- crease in the return on crop production. Natu- rally it is also possible that the higher crop pro- duction would be processed into livestock prod- ucts, in which case the increase in the value of the totalproduction wouldbe considerably larg- er due to the increased value added (with cer- tain reservations, of course). On the other hand, quotas may restrict the growth in livestock pro- duction in the short term (Kettunen 1995), but in the longer term, e.g. by 2050, these restric- tions, may not apply. Economic effects The following calculations have been done at the farm and state level. At the farm level prices are given and the farmer adjusts the production according to the prices of output and input and the endowments available. The prices are deter- mined or influenced by the agricultural policy of a country or economic region (like the EU). Prices are also affected by the world markets depending on the closeness or openness of the country or the economic region. The effect var- ies according the product concerned. Cereals are easily transported around the world and, there- fore, climate change will affect the world mar- ket prices of cereals. The same applies to beef and mutton prices, whereas the prices of other animal products may differ from one region to another and, thus, climate change may not af- fect the prices equally in all parts of the globe. (For more sophisticated methods to evaluate eco- nomic effects see Mendelsohn et al. 1994). Assumptions Since the estimates of the growth of the yield level and the change in the use of pesticides are uncertain, two hypothetical examples of the ef- fects of climate change are given in Table 1. Farm models developed at the Agricultural Econom- ics Research Institute are applied for this pur- pose. The calculations are based on the assump- tion of a 10% growth of the yield level and a 10% increase in the costs of plant protection. These assumptions do not correspond to any scenario. However, these results can easily be applied to any specified scenario which gives the increase of yields and change in the use of pes- ticides. In the following calculations no changes are assumed to occur in the prices. The change in the yield level is the most sig- nificant factor in economic calculations. Eco- nomic effects are estimated in the following as- suming that a) production growth corresponds to the increase in the yield level and b) no changes occur in the use of inputs except for the increase in the use of pesticides and additional harvesting costs for the increased yield. The base scenario is the situation in 1995. The correct way would be to determine the eco- nomic situation in the year corresponding to the 10% increase in the yield level. This is not yet possible. However, it does not affect the con- clusion if prices are kept constant, as is done in this study. Calculations Farm calculations developed at the Agricultural Economics Research Institute were originally used for examining the adjustment to member- ship of the EU in 1995 (Hiiva and Alastalo, per- sonal communication). The data are from book- keeping farms, which means that theresults can- not be generalised for the whole country. How- ever, they provide interesting information on the income development of individual farms as the prices and amount of support vary. These calcu- lations can also be applied for examining the effects of climate change at the farm level. The figures for 1995 in Table 1 refer to averages of a group of crop and dairy farms. In the calculations of returns, only the in- crease in yield is taken into account in estimat- ing the economic effects. For dairy farms, the increase in yield is assumed to lower feeding 381 Vol. 5 (1996): 377-385. AGRICULTURAL AND FOOD SCIENCE IN FINLAND Kettunen , L: Potential economic effects ofclimate change on Finnish agriculture Table I. Two examples of the change in the farm income due to the 10% increase in yields. crop farm dairy farm 1995 2050 (change) 1995 2050 (change) Total area, ha 45.8 29.4 Total yield, feed units 162 200 +l6 220 68 700 +6870 Corresponding area, ha 35.6 20.8 Yield, feed units per ha 4558 3304 Price of feed unit, FIM 0.90 0.70 Gross return, FIM -crop 146 391 +l4 639 317 - animal products 226 344 772 - subsidies 96 953 64 806 other 8289 4787 total 251 858 +l4 639 414 682 Costs -drying 1207 +Bll 1505 - plant protection 1 11 396 +1,140 1974 +197 - purchased feed2 170 45 399 -4809 - other 209 088 266 299 total 221 691 +1951 269 778 -4612 Farm income 30 167 +l2 688 144 904 +4612 Change in % +42 +3.2 1 Plant protection costs +lO%. 2 for the dairy farm the increase in yields is assumed to lower the feeding costs. costs, and this is valued using the price of fod- der cereals (FIM 0.70/kg). In the costs the changes in plant protection and drying the additional crop (FIM 0.05/kg) are taken into account. At this stage all other factors are allowed to remain as before. The farm model calculation shows that in- comes increase (ceteris paribus) by about FIM 12 700 (42%) on the crop farm and FIM 4 600 on the dairy farm due to the 10% increase in the yield level (Table 1). In the calculation no changes are assumed to occur in prices and the amounts of support. This assumption will not hold in long-term forecasts. Market forces are going to influence prices in many ways. The population grows rapidly, and it is questionable whether supply can grow at the same pace in the long run. Gradually it will be- come necessary to start using marginal land for production, and this will lead to a considerable increase in the production costs. There are also other factors that are likely to cause the prices to rise, and the increase must either be paid di- rectly by the consumers or it will lead to chang- es in the structure of consumption. Even though the greenhouse effect has been estimated to have a relatively small impact on agricultural produc- tion at the global level, crop prices may rise a lot (Parry et al. 1996). Estimates concerning agriculture as a whole A macro level study concerning the whole coun- try can be made simply by first estimating the value of the increase in the yield level by one percentage point. The crop production of the whole country has amounted to 5 200 million- -5 400 million fodder units (Kettunen 1995). The 382 AGRICULTURAL AND FOOD SCIENCE IN FINLAND price of barley, FIM 0.70/kg, can be used as the value of a fodder unit. Using an average total yield of 5 300 million f.u., an increase in the yield level by one percentage point increases the return by about FIM 37 million. If the produc- tion increases by 10%, the benefit is FIM 370 million. In Finland there is altogether about 120 000 ha pasture. The quantity of fodder units this yields can roughly be estimated at 360 million f.u., and thus its value would be about FIM 288 million. If an increase in the yield is assumed to be 10%, the value of the longer pasture season could be 10%, i.e. FIM 28.8 million. The total cost of plant protection has amount- ed to about FIM 300 million (Kettunen 1995). This can be expected to rise by FIM 30-60 mil- lion. The harvesting cost of the increased yield is about FIM 0.05/kg, i.e. about FIM 7.5 million for 150 million kg. The increase in costs is only 5% of the increase in returns. The calculations of returns include a large margin of error. The increase in costs remains quite small. The totaleffect of a 10% increase in the yield level is about FIM 360 million, i.e. 6% of the total farm income ofFIM 6 000 million (see also Kettunen 1988). Other estimates Kuoppamäki (1995) has estimated the effects of climate change on the whole national economy, and his study also includes a short chapter on agriculture. According to his study, by the year 2050 the benefit to agriculture will be FIM 1.255 billion, and in relation to the annual agricultural income ofFIM 6 billion the increase is 20%. This is based on an increase of the yield level by 40%, growth of horticultural production by 50%, and a decrease of 10% in the costs of animal fodder as a result of the longer pasture season. The es- timate is in line (a little smaller) with the esti- mate above. The second method for estimating the bene- fits to agriculture presented by Kuoppamäki (1995) is also interesting. It is based on the price of land, which he assumes to increase along with rising temperatures. On the basis of a function estimated from a cross section of data over Fin- land: land price = f(temperature). Kuoppamäki (1995) arrives at an estimate according to which the benefit to agriculture is FIM 2.2 billion. When the fertilizer effect of C0 2 is taken into account a further multiplication factor of 1.2 is applied and the total benefit is FIM 2.7 billion. The methods presented by Kuoppamäki can be criticised for the part concerning the depend- ence between the price of land and temperature. It might be more appropriate to estimate the de- pendence between the price of land and yield level. Even if the temperatures rise in the north- ern parts of the country, the production capacity of the land does not necessarily increase in the same proportion. Discussion In the assessment of the economic effects of cli- mate change, changes at the farm level, i.e. in returns and costs, have to be taken into consid- eration. Changes in returns are mainly caused by changes in the yield level, but yield quality may also improve ifthe growing season is long- er and the temperatures higher. As the tempera- tures rise in Finland, the cultivation zones of different crops may move further to the north. New breeds or even new crops may increase the returns. Costs are influencedby various factors. Har- vesting conditions may improve as the temper- atures are higher and the growing season is long- er, which reduces costs. However, an increasing need for pest control results in higher costs. An increase in productivity increases the price of land, at least in principle, which also leads to cost increases. In a free economy, increase in the supply re- sults in a decrease in the price level. If we focus on Finland only, as distinct from other countries, it can be assumed that the price level will not change, as prices are determined for the whole 383 Vol. 5 (1996): 377-385. AGRICULTURAL AND FOOD SCIENCE IN FINLAND Kettunen, L.: Potential economic effects ofclimate change on Finnish agriculture EU area. If the greenhouse effect is looked at from the global perspective, the assumption is not true. The field crop production of the whole world is going to change, which inevitably af- fects world market prices. The effect on na- tional agricultural production depends on the border controls used. Changes in world market prices are likely to influence the national econo- my through national support policies. It is very difficult to estimate the long-term development of cultivated area. With free com- petition the area under cultivation increases as profitability and comparative advantage im- prove. Under present EU pricing policy, hec- tarage support determines the maximum area un- der cultivation. In the very long run (e.g. by 2050) the need for increasing cereal production in the world seems obvious due to population growth. In this situation the growing potential of the northern areas is likely to be utilised in full. Various extensive studies have indicated that the greenhouse effect increases the crop poten- tial in Finland. The benefit is visible both as an increase in crop production and as lower costs in animal husbandry. From the economic point of view the increase in yield level is highly sig- nificant. It is almost pure income, because the increase in the costs remains quite small.A 10% increase in the yield level raises the farm income by about 6%. In particular, the benefit will be important for crop producers. Because agriculture is supported in many ways either directly (direct income support) or indirectly (by tariffs or subsidies), a rise in the income level may be offset by lowering the sup- port. Consequently, farmers may not benefit from an increase in yield level, but the benefit will go to the state economy. However, an increase in yields resulting from rising temperatures is ad- vantageous to the national economy, regardless of whether the benefit goes to the farmers or to the state. References Carter,T.R. 1996. Developing scenarios of atmosphere, weather and climate for northern regions.Agricultural and Food Science in Finland 5: 235-249 (this issue). Saarikko, R., Hlirsalmi, H., Kaukoranta, T., Kleemo- la, J., Kontturi, M., Mela, T., Rehu, E., Sippola, J. & Tiilikkala, K. 1992. Maatalous. (Agriculture) In: Kanni- nen, M. (ed.). Muuttuva ilmakehä (The Changing Atmos- phere). Academy of Finland, p. 95-102. -, Saarikko, R.A. & Niemi, K.T. 1996. Assessing the risks and uncertainties of regional crop potential under a changing climate in Finland. Agricultural and Food Sci- ence in Finland 5: 329-350 (this issue). Fischer, G., Frohberg, K., Parry, M.L. & Rosenzweig, C. 1994. Climate changeand world food supply, demand and trade. Global Environmental Change 4: 7-23. Hakala, K. & Mela, T. 1996. The effects of prolonged exposure to elevated CC2 levels on the growth, yield and dry matter partitioning of field-sown meadow fescue. Agricultural and Food Science in Finland 5: 285-298 (this issue). Harrison, P.A., Butterfield, R.E. & Downing,T.E. (eds.), 1995.Climate change and agriculture in Europe; assess- ment of impacts and adaptations. Research Report No. 9, Environmental Change Unit, University of Oxford. Kaukoranta,!. 1996. Impact of global warming on pota- to late blight: risk, yield loss and control. Agricultural and Food Science in Finland 5: 311-327 (this issue). Kettunen, L. 1988. The Effects of climatic variations on agriculture in Finland. Conclusions and implications for policy. In: Parry, M. L. et al, (eds.). The impact of climat- ic variations on agriculture. Vol 1: Assessments in cool temperature and cold regions. Kluwer, Dordrecht, The Netherlands, p. 599-607. - 1995. Finnish Agriculture 1994. Agricultural Econom- ics Research Institute, Research Publications 76a. 63 p. - & Niemi J. 1994. The EU Settlement of Finnish Agri- culture and National Support. Agricultural Economics Research Institute, Research Publications 75a. 92 p. Kleemola, J. & Karvonen,!. 1996. Modelling growth and nitrogen balance of barley under ambient and future conditions. Agricultural and Food Science in Finland 5: 299-310 (this issue). Kuoppamäki, P. 1995. Climate change and the Finnish economy. The Research Institute of the Finnish Econo- my, ETLA. Discussion papers No. 529. 55 p. Mela.T., Carter,!., Hakala, K., Hannukkala, A., Lauri- la, H., Niemi, K., Saarikko, R. & Tiilikkala, K. 1996. The effects of climatic change on crop production: re- sults of a five-year research project. In: Roos, J. (ed.). The Finnish Research Programme on Climatic change: 384 AGRICULTURAL AND FOOD SCIENCE IN FINLAND Final Report. Publications of the Academy of Finland 4/ 96, Helsinki, p. 324-336, Mendelsohn,R., Nordhaus, W.D. & Shaw, D. 1994,The Impact of global warming on agriculture: a ricardian anal- ysis. American Economic Review 84: 753-771. Mukula, J. 1988. The effects of climatic variations on agriculture in Finland. The effects on barley yields. In: Parry, M. L. et al. (eds.). The Impact of climatic varia- tions on agriculture, Vol. 1: Assessments in cool temper- ate and cold regions. Kluwer, Dordrecht, The Netherlands, p. 547-563. Parry, M.L., Hossell, J.E., Jones, P.J., Rehman, T., Tranter, R.8., Marsh, J.S., Rosenzweig, C., Fischer, G., Carson, I.G. & Bunce, R.G.H. 1996. Integrating glo- bal and regional analyses of the effects of climate change; a case study of land use in England and Wales. Climatic Change 32: 185-198. Rantanen, O. 1988. The effects of climatic variations on agriculture in Finland. The effects on spring wheat yield. In: Parry, M. L. et al. (eds.).The Impact of climatic varia- tions on agriculture, Vol, 1: Assessments in cool temper- ate and cold regions. Kluwer, Dordrecht, The Netherlands, p. 565-577. Reilly, J., Hohmann, N. & Kane, S. 1994. Climate change and agricultural trade: who benefits, who loses? Global Environmental Change 4: 24-36. Rosenzweig, C. & Parry, M.L. 1994. Potential Impact of climate change on world food supply. Nature 367: 133- 138. SELOSTUS Ilmastonmuutoksen taloudelliset vaikutukset suomalaiseen maatalouteen Lauri Kettunen Maatalouden taloudellinen tutkimuslaitos Kun arvioidaan ilmastonmuutoksen taloudellisia vai- kutuksia Suomen maataloudelle, on otettava huo- mioon sekä kustannusten että tulojen muutokset. Tu- loihin vaikuttavat pääasiassa satotason muutokset, muttakustannuksiin useat eri tekijät. Korjuuolot saat- tavat muuttua suotuisemmiksi keskilämpötilan nous- tessa, mikä pienentää kustannuksia. Toisaalta olosuh- teet muuttuvatotollisemmiksi myös kasvitaudeille ja tuhoeläimille, mikä puolestaan aiheuttaa lisäkustan- nuksia. Monet tutkimukset ovat osoittaneet, että läm- pötilan kohoaminen ja ilman hiilidioksidipitoisuuden nousu lisäävät satopotentiaalia Suomessa. Taloudel- liselta kannalta satotason nousu on hyvin merkittävä seikka, sillä samanaikaisesti kustannukset kohoavat melko vähän: 10 % satotason nousu lisää tilan tuloja 6 %. Koska maataloutta tuetaan monella tavoin joko suorasti tai epäsuorasti, tulojen nousu voi jäädä mer- kityksettömäksi tukien vähetessä. Tällöin satotason noususta aiheutuva lisätulo ei hyödyttäisi viljelijää, vaan valtiontaloutta. Kohonneesta lämpötilasta aiheu- tuva satotason nousu on kuitenkin edullista koko kan- santalouden kannalta riippumatta siitä, saako hyödyn viljelijä vai valtio. 385 Vol. 5 (1996): 377-385. AGRICULTURAL AND FOOD SCIENCE IN FINLAND