It is analyzed that, because of global warming, the average temperature has risen 1.5℃ (1.9℃ in winter and 0.3℃ in summer) for the past 100 years and winter has shortened while summer has lengthened, and thus advancing the flowering season in spring. As a result, the agricultural cultivation area has been extended northward and the damage by blight and harmful insects during the winter has increased, resulting in the decrease in agricultural productivity.
Scientific diagnosis and evaluation of the impacts of climate change on the agricultural sector is very important in establishing future visions of the agricultural industry and the direction of its policies. It especially provides useful information for establishing adaptive plans such as long-term regional agricultural plans and farming plans.
The purpose of this study is to present a systematic and step-by-step strategy for the agricultural sector by making a diagnosis of the climate change phenomenon and carrying out an in-depth analysis of its impacts on the agricultural sector. Of the 2-year project carried out to achieve this purpose, the first-year study completed this year focused on the analysis of the impacts of climate change on the agricultural sector and the second-year study to be executed next year will present strategies for coping with the impacts based on the result of the analysis.
In this report, Chapter I presents the introduction which covers the necessity of this study and the review of previous studies; Chapter 2 describes the actual conditions of domestic and international climate changes along with the future prospect; Chapter 3 reviews a theoretical approach to analyze the impacts of climate change on the agricultural sector; Chapter 4 presents the reactions of the agricultural industry to climate changed based on the results of a survey of farmers and the people in charge of agricultural policies; Chapter 5 analyzes the impacts of climate change on agricultural productivity and agricultural economy; Chapter 6 examines the cases of major countries such as Japan, USA, and EU countries with regard to the analysis of the impacts on the agricultural sector; and Chapter 7 summarizes and concludes this study.
The highlights of the study are summarized as follows:
First, according to the results of climate change forecasted by National Institute of Meteorological Research (NIMR), it is suggested that the average temperature will rise 1.5℃ by 2020, 3.0℃ by 2050 and 5.0℃ by 2080 from that of the past 30 years (1971 ~ 2000). As for the precipitation, it is estimated to have an increase 5% by 2020, 7% by 2050 and 15% by 2080.
Second, the temperature rise due to climate change gives rise to new harmful insects, resulting in increased damages to crops. In particular, it appears that the damages by brown grasshoppers to apples, peaches, grapes and beans have increased. As for rice crops, the areas affected by rice stripe virus appear to have moved northward and spread all over the country.
Third, in order to identify the level of recognition of climate change, a survey was conducted on farmers and experts. According to the result of the survey, it appeared that the farmers had generally recognized climate change for 5 years and had seriously worried about its negative impacts. It was shown that the experts had also recognized its impacts to a considerable extent. They expressed their deep concerns about the occurrence of harmful insects caused by global warming and mentioned the problems of abnormal weather conditions and water shortage as important issues.
Fourth, for an analysis of the agricultural productivity under the influence of climate change, non-parametric and semi-parametric kernel analysis methods were applied to the four crops of rice, Korean cabbage, radish and apples based on the agricultural product and weather data obtained from their major producing districts for the period from 1975 to 2007. In the case of rice, the most representative crop of Korea, a temperature rise of 1℃ increased the yield of rice per unit area (10a, approximately 1,000㎡) by 24.4kg when the average temperature during the cultivation period was 19℃ or lower. When the average temperature was higher than 19℃, however, the yield of rice per unit area decreased by about 6.2kg. It appeared that the productivities of Korean cabbage, radish, and apple were affected by different factors of crops and districts.
Fifth, to analyze the impact of climate change on the property of farm households, Ricardian model was applied. The result showed that the rise of 1℃ in the annual average temperature (12.4℃) brought down the price of farmland per ha by approximately KRW 14.5～19.2 million approximately, equivalent to a 5.7～7.5% drop in the average farmland price. On the other hand, an increase of 1㎜ in the monthly average precipitation (110.8㎜) was estimated to increase the farmland price per ha by KRW 330～360 thousand.
Sixth, on the assumption that the average temperature would rise by about 1.2℃ in 2020 and the precipitation would increase by 11% (applying the forecast by NIMR) in the same year, it was estimated that the temperature rise would reduce the farmland price per ha by KRW 14.5~19.2 million; but the increase in the precipitation, on the other hand, is estimated to raise the farmland price per ha by KRW 4.0~4.4 million, thus resulting in the fall of about KRW 13.4~18.7 million per ha in the farmland price.
Lastly, according to the Ricardian analysis result of the impact of climate change on the property of farm households, it appeared that the temperature rise in April had a positive influence on the farm household's total income whereas it had a negative influence in August and December. When such seasonal influences were considered collectively, it was shown that the temperature rise of 1℃ reduced the farm household's total income by KRW 2.6~4 million per ha, equivalent to about 15 ~ 23% of KRW 17 million of the average farm household's total income. This implies that climate change has a bigger impact on the farm household's total income than on the farmland price.
When the Ricardian analysis results of the economic impacts of climate change on the agricultural sector were put together, it appeared that climate change, including both temperature and precipitation, had predominantly negative impacts as suggested by previous studies conducted by major countries. Therefore, in order to minimize negative impacts of climate change, proper adaptive measures are needed, which include insurance system for risk management, breed improvement, introduction of new breeds and modification of cultivation methods. Based on the results of the impact analysis conducted in the first-year study, the second-year study will focus on developing core policies and phased-out implementation strategies (short-, mid- and long-term strategies) to effectively cope with climate change.

Researchers: Kim Chang-Gil, Park Hyun-Tae, Lee Sang-Min, Joo Hyun-Jeong, Kwon Oh-Sang and Robert Mendelsohn
E-mail address: changgil@krei.re.kr