Global warming has serious implications for all aspects of human life, including elevated sea levels, crop failure and famine, changes in global rainfall patterns, changes to plant and animal populations, and serious health effects. Especially Infectious diseases are global entities that depend dynamically on the interaction between the population and the existing regional climate. The global warming requires a basic understanding of the greenhouse effect. In nature, the greenhouse effect is responsible for elevating the Earth’s temperature, making it possible for life to thrive. Greenhouse gases include carbon dioxide, methane, nitrous oxide, hydrocarbons, per fluorocarbons and sulfur hexafluoride. Population size and global warming are related because human activities increase production of greenhouse gases. This effect culminates in global warming and ecosystem. Severe weather events may result in injuries and fatalities, and heat waves can cause direct effects such as dehydration heat asthenia, hear exhaustion, heat stroke, and respiratory disease. Earth system changes increasing climate variability, increased rainfall in some areas and drought in others, and more frequent severe weather events, have considerable potential to affect human health. Impact of Climate change on Public Health is difficult to quantify the exact risk. Particularly, about infectious diseases, the impact depends on the complex interaction between the human host population and the causative infectious agent. Important human factors include crowding, food scarcity, poverty, and local environmental decline. Some health effects of climate change may result from indirect impacts on natural ecosystems Ecosystem changes can increase the rage, seasonality, and infectivity of some vector borne disease. For example, altered climatic conditions can change the habitats of vectors such as mosquitoes or rats and affect the parasites they carry. Changing the abundance and geographic range of carriers and parasites could shift the seasonal occurrence of many infectious diseases and cause them to spread. Heavy rain falls and related factors are associated with water borne disease outbreaks, and these may increase the risk of food borne illness. Higher levels of carbon dioxide and heat may promote production of allergens by such plants as ragweed, and warmer weather may promote the formation of groundlevel ozone. Humidity combined with heat facilitates fungal growth and transmission The World Health Organization estimated, in its "World Health Report 2002", that climate change was estimated to be responsible in 2000 for approximately 2.4% of worldwide diarrhoea, and 6% of malaria in some middle-income countries . However, small changes, against a noisy background of ongoing changes in other causal factors, are hard to identify. Clearly, global warming will cause changes in the epidemiology of infectious diseases. The ability of mankind to react or adapt is dependent upon the magnitude and speed of the change. The outcome will also depend on our ability to recognize epidemics early, to contain them effectively, to provide appropriate treatment, and to commit resources to prevention and research This article will introduce the concepts of global warming, focus on the impact of climate changes on human health and infectious disease, and present future strategy in KCDC

Global warming is one of the most buzzing words these days, as the average temperature increased up to 6.4℃ before the end of 21st century and the water level to 59cm causing severe draught, heavy snowfall, and monster typhoon all over the world. The capacity of natural ecosystem will not be able to contain such changes. Many of the species will be endangered and some of them are warned to be extinct, and accordingly water and food supply will not meet the demand of human. In 2007, IPCC, Inter Governmental Panel on Climate Change, made fourth report about global warming and estimated that the CO2 content in the atmosphere increased about 1.35 times to 379ppm at 2005 from 280ppm before the industrialization period pulling the average air temperature up by 0.7℃ a year. The water level as well increased by 1.8mm a year as the polar iceberg and permanent snow melt down. Global warming caused by environmental pollution and greenhouse gas may lead to the increase of price of not only agricultural product but also the industrial products as a consequence, a phenomenon so called Ecoflation, Ecology+inflation. IPCC forecasted that if the present phase use of fossil energy continues the air temperature in 2090-2099 will increase by 4℃ and the water level by 26-59cm compared to that of 1980-1999, warning particularly that the average increase of global temperature by 1.5-2.5℃ a year will put the species of 20-30% into danger of extinction. According to the report by the Korea National Statistical Office about the effect of climate change on the production of agriculture and fishery, the cultivation area of apple which is typical temperate fruit decreased to 29,204ha in 2007 from 52,447ha in 1992. On the other hand the cultivation area of peach increased greatly to 15,014ha(2005) compared to 12,000ha in 1996 as it became possible to grow wherever in Korea. Similar change can also be found for orange and grape, orange can be grown in Jeonnam and Kyuongnam province, and grape in Kangwon province. Jeju island and southern coastal area of Korea worry about the inhabitation of subtropical pests when they invade these area, in fact the pest outbreak as a result of the increase of generation a year is ever more frequent. The typical examples are Paratlanticus ussuriensis (Uvarov), the lantern fly, Lycorma delicatula, and the fruit moths like Carposina sasakii Walsingham.

Insect occurrence is closed related to crop and environment. Global climate changes as environment factor influencing not only crops but also insects on their behavior, distribution, development, survival and reproduction. Insect life stage are most often calculated using accumulated degree days from base temperature and biofix point. Temperature is also main factor to changes in moisture humidity and CO2 that effect on crop and insect development. Precipitation is another climate change on consideration factor to insect survival. Therefore, the precise impacts of climate change on insects is somewhat uncertain because it may change favor some insects while others may inhibit their development. On predicting the impact of climate change on insect is very complex exercise and need closed cooperation with experts on modeling. Some generalized predictions can be made, based on current pest distributions and severity of insect outbreaks in individual regions. At the present in Thailand, some alien insect species often present by global trades as by climate change.

Forest pests are one of the major disturbance factors in forest ecosystem and their outbreaks are expected to be severer under influence of climate changes. Among the forest pests, coleopterans can be key stone species because they are one of the dominant groups in forest and their ecological functions are very diverse. Moreover, saproxylic beetles contributed to ecological succession of forests thus, ecological functions of forests are changed in response to their outbreaks. The outbreaks of mountain pine beetle (MPB) were the most dramatic examples that outbreaks by climate change induce changes in ecological function of forest. Compositions of coleopteran species were variable to latitudinal changes whereas compositions of functional group were consistent. This showed that ecological function of coleopteran had resilience to climate changes and directions of changes in coleopteran communities were predictable based on species-specific latitudinal distribution. In addition, abundance of saproxylic beetles increased with increase in DBH (diameter at breast height), suggesting tree ages are one of the key factors for saproxylic beetles. Finally, potential changes in interactions between saproxylic beetles and trees under climate changes were discussed.

The performance of herbivores is directly determined by the quality of host plants which changed rapidly with abiotic environment. Elevated CO2-induced nitrogen decreases in plant foliage reduces the growth of chewing herbivorous insects. In contract, although aphids had species-specific response to elevated CO2, it was still considered that aphids’ population have been found to be the only feeding guild to respond positively to elevated CO2. Few studies of elevated CO2 effects on sap-feeding aphids can explain why aphids would make its success under elevated CO2 environment. Plant re-allocates the carbon and nitrogen in tissue under elevated CO2, and in turn alters structure of plant leaves, reduces the amino acid content of phloem sap and increased secondary metabolites of plant. However, it is difficult and unreasonable to predict the general response of aphids to elevated CO2 by using a single plant component. Instead, it is more likely that, in terms of interacting with host plant, aphids are trying to overcome the disadvantages of elevated CO2 and maximum their fitness under elevated CO2 environment. It may provide several cues to explain why individual species will achieve success under future elevated CO2. The present paper reviews recent studies of elevated CO2 effects on aphids and discusses the effects of elevated CO2 on aphid performance on crops using cotton and cereal aphids as examples. Further work examining induced defense of plant against aphids under elevated CO2 will contribute largely to current knowledge.

Currently there is a great increase in concern about the safety of food we eat and the potential hazards arising from contamination with synthetic pesticide residues on crops. In general, consumers tend to believe that synthetic pesticides and there residues in crops are dangerous to our health. On the other hand, less attention has been paid to the naturally occurring toxic substances in crops, which may cause or contribute to illness in humans. The Korean peninsula is very hot and humid during the summer season. This environment is good for the growth of various kinds of pests and pathogens as well as crops. Therefore, Korea has been one of the most intensive pesticide consuming countries of the world, an attractive market for multinational pesticide companies. In order to control the diseases, pests and weeds effectively, the use of pesticides in agriculture is inevitable. The pesticides protect the reduction of production from diseases, insect pests and weeds. Furthermore, they provide the stable food and crop supply by improving the quality. Thus, the pesticides are the most economical and safe substance to replace and cover the shortage of rural work force, which gets more and more serious. Pesticide industry in Korea has just a short history of 50 years. Taking the procedures of the import, adoption and imitation of the foreign technologies, five compounds were synthesized newly by our technology and registered as insecticide, fungicide and herbicide. Until now the most of pesticide technicals were imported from foreign countries with high price. The imported technicals are formulating with adjuvant in manufacture factory. From the 1970s a part of technicals which is expired patent are synthesizing by our own technology. Totally of 1,230 items has been notified to be used as pesticide by the government at 2008. The pesticide production in 2008 was 21,168 M/T as an active ingredient. The amount was divided 17.5% for paddy rice, 45.4% for horticultural plants, 26.2% for weed and 10.9% for others. By formulation, emulsifiable concentrate is 46.3%, wettable powder 32.6%, granule 17.5%, dust 0.8% and water soluble powder 0.7%. The total amount of imported pesticide was 443,362 thousand dollars. Among them the technical grade is 77.4%, intermediates for synthesis 4.1%, formulation 18.5%. The technical grade was divided with fungicides 28.7%, insecticides 34.2%, herbicides 26.2% and others 10.9%. The major importing countries are Japan 29%, Germany 15.2%, United State 15%, China 12.6%, Swiss 8.4% and others 29%. The local production ratio of technicals is 10.6% of the required technicals in Korea. On the other hand, Korea is exporting some technical grade and formulations to several nations. The agrochemical market value of Korea in 2008 was 27,586 thousand dollars. The ideal pesticide would be toxic only to the target organism, but unfortunately this cannot often be achieved and most pesticides are to some extent hazardous to other organisms also and, therefore, potentially harmful to those handling them. At present 2008, the maximum residue limit (MRL) for 399 pesticides was established in all crops. And the standard for safe use for 800 items except herbicides was also established in each crop. Every year, Korean government is monitoring the residue level of pesticides to agricultural products for safety of consumers. The classification of pesticides toxicity by the Pesticides Management Law is based primarily on its acute oral and dermal toxicity to test animals. This hazard classification of Korea is following the method of WHO. The hazard class is divided into 4 groups; extremely hazardous, highly hazardous, moderately hazardous and lowly hazardous. Among 1,230 items including 28 items of biopesticide using in Korea, there is no extremely hazardous group, 17 items in highly hazardous group, 175 moderately hazardous and 1,038 lowly hazardous. Apart from classification system by acute toxicity, to minimize the side effects caused by pesticides we have another system prescribing definitely the enforcement degree of crop-residual, soil-residual and water-residual pesticides. Crop-residual pesticide is legally defined as the agrochemical that its terminal residue level in crop harvests exceeds the national maximum residue limit. The residual pesticide of which its persistence is evaluated to have longer than 180 days of half life in soil and the residual impacts on the second cropping is recognized, donates as the soil-residual pesticide. And both of crop and soil residual pesticides are prohibited to register for use. Water residual pesticide of which the fish toxicity (TLm, 48hrs) to the carp is less than 0.1ppm is also legally regulated and banned for use in paddy field. What kinds of pesticides are required for the future of Korean agriculture? Everybody will reply. "They must have the high activity, be safe and without harmful effects to the animals and environment". But actually the development of ideal pesticides in Korea is very difficult owing to invest of lots of money and time. So we are using the technology of molecular design for toxicity reduction of already existing pesticides, and research for development of biopesticides by the bioengineering technique using plants and microorganism. To use pesticides effectively, we have to research and evaluate of integrated control measures including development of biological, enzyme and hormone manipulation, and mechanical controls resulting in pest management concepts. For the future, it is necessary to produce and use more effective and more selective pesticides. Over the development of synthetic pesticides from 1940s there have been significant changes in the tools available for research and development of pesticides. Research on pesticides has gone from spray and prays to high throughput screening on in vitro targets. Analytical techniques of pesticides now allow easier identification of metabolites and degradation products, whilst parts per trillion can be routinely determined. These changes have been largely driven by advances in computing power over the past decades. Similarly, the modeling for development of new pesticides that can now be carried out would have seemed impossible 50 years ago. Information today is also much more readily accessible than before, the internet is a tool which has come of age and is the repository of a large amount of information. Communications have similarly changed with personal mail allowing instant communication with fellow scientists. In the future, international cooperation will be more needed for the exchange of related and updated information in safety evaluation and development of pesticides.

Ecological changes, both man-made and natural, have changed the landscape of the Republic of Korea following the end of Japanese occupation at the end of World War II (1939-1945). During the Japanese occupation, forested hillsides were cleared and wood products shipped to Japan, leaving the hills and mountains largely covered by grasses and other shrub vegetation. Following WWII, the country of Korea was divided into North and South Koreas, with North Korea under communist powers, while South Korea was established as a democratic government. In South Korea poverty was rampant and local populations scavenged for wood for cooking and heating during the cold winters. Just as economic conditions were increasing, South Korea was attached by North Korea, beginning a long drawn-out conflict from 1950 to the summer of 1953, whereby an armistice was signed and an often uneasy peace between the two countries continues today. Again, the Republic of Korea emerged from a War as an impoverished country with treeless country sides, hills, and mountains. In the 1960’s, president Chung-Hee Park established a tree planting policy to reestablish long-ago lavish forested mountains and hillsides that make up more than 70% of the South Korean landscape. Today, mountains and hillsides are generally not used for agriculture and are completely forested, with planted groves and volunteer trees ranging in age from 10-50 years. These forested areas have led to increased protection for large and small mammals and birds, increasing the potential for zoonotic pathogens that there ectoparasites harbor to be transmitted to man during work and leisure activities. While forested areas provided an expanded habitat for some animals, agriculture expanded and modernized, resulting in short-cut grasses on banks separating much of the rice paddies, orchards, ditches, and dry-land farming that increased competition for small mammal habitat. As a result of increased surveillance of small and large animals and their ectoparasites, the increased prevalence of known pathogens and identification of new pathogens, especially those harbored by ticks, has demonstrated the presence of tick-borne encephalitis, several species of spotted fever group Rickettsia, and a host of other zoonotic diseases in wild animals, their ectoparasites, and man. As tick-borne diseases are not reportable diseases in Korea, the extent and impact on civilian and military populations is unknown as diagnoses are often likely sought for the wrong pathogen. While agriculture modernized, military training sites largely consist of unmanaged lands with tall grasses that are conducive to large and small mammal populations, which are host to a number of zoonotic diseases, e.g., hantaviruses, scrub typhus, murine typhus, leptospirosis, tick-borne encephalitis, spotted fever group rickettsial pathogens, Lyme disease, bartonellosis, etc. that impact on military populations training in those areas. The impact of training sites habitat modification has not been assessed, but for many sites is impractical. To reduce health risks of vectorborne diseases, the US Army has established better housing (tents to barracks with screened windows and air conditioning) at some field training sites, reducing the potential for the transmission of mosquito-borne pathogens (malaria and Japanese encephalitis virus). The increased use of permethrin-treated all climate uniforms (ACUs) and repellents, also reduce the potential for transmission of mosquito-, tick-, mite-, and flea-borne pathogens. However, training conditions at some field training sites remain largely unchanged, with personnel working and sleeping in tents that abut to forested areas where animals and their ectoparasites are present. While some training and maneuver sites are well planned for weapons qualifications of wheeled and tracked vehicles, others sites are in areas of unmanaged lands which are rodent infested. Increased surveillance by the 65th Medical Brigade not only provides a baseline and relative distribution for vector-borne diseases in Korea, but also provides disease trends and risk assessments that are necessary for protecting US military personnel training in Korea.

Thailand suffers from one of the highest rates of dengue and dengue haemorrhagic fever in the world. Since there is no vaccine or any specific treatments for dengue, currently, the only effective way to prevent dengue fever and dengue hemorrhagic fever is vector control. The knowledge of basic biology, ecology, behavior and survival factors of Ae. aegypti is crucial to control mosquitoes. The impact of the environmental factors; temperature, rainfall, and humidity, on the ecology, biology, development, vector density, behavior, fitness of mosquito vectors, and the mosquito-borne disease transmission dynamics will be presented and discussed.

Vector-borne diseases are transmitted to humans by blood-feeding arthropods such as mosquitoes, ticks, and fleas. These cold-blooded animals are influenced by environmental change. A recent report by IPCC showed that the emission of greenhouse gases has already changed world climates. Heat waves in Europe, rises in global mean sea level, summer droughts and wild fires, more intense precipitation, and increasing numbers of large cyclones, hurricanes and typhoon may be typical example of extreme climate phenomena related to global warming. High temperatures during winter season may increase survival rate among arthropod vectors in Temperate Zone. Warming may accelerate the spread of mosquitoes such as Aedes albopictus in the northern parts of Japan and European countries. The spread of the mosquito vector through global used-tire trading in recent decades to Africa, the Mideast, Europe, and North and South America caused an outbreak of Chikungunya fever in north Italy in 2007.

Deciduous tree fruits such as pears and apples are widely grown in the Pacific Northwest of the United States and are well adapted to the seasonal environment in that region. Extended cold periods provide adequate chilling to break dormancy and reinitiate growth in the spring. Cold exposure synchronizes the physiological processes and makes sure that bloom is uniform and that fruit matures in a uniform manner. As a result of global warming, some fruit-growing areas may experience inadequate cold exposure during the winter months, gradually shifting the southern boundary for production of deciduous fruits further north. However, climate change will affect not only growth and fruiting habits of fruit trees but also the insect and mite pests which feed on them. There is general agreement that in temperate regions a trend towards warmer summers and milder winters will generally benefit insect and mite pests and increase their injuriousness. Temperature changes in particular will impact the development, mortality, phenology, and voltinism of fruit pests. Here we discuss how climate change may affect pests and control practices on deciduous tree fruits in the Hood River Valley of northern Oregon. This small valley extends in a north-south direction from the Columbia River to the foothills of Mt. Hood and is characterized by a varied topography and large altitudinal differences (sea level to 600 m). The major pest of pears and apples in that area is codling moth, Cydia pomonella L., a cosmopolitan pest which is present in most deciduous fruit-growing areas of the world. Like its host trees, the codling moth is well adapted to a seasonal environment. Diapause is the principal mechanism which synchronizes its phenology with the tree and the presence of fruit, the larval food source. Diapausing overwintering larvae require cold exposure (chilling) to terminate diapause in late winter or early spring. At the lower elevations close to the Columbia River the codling moth is bivoltine but gradually becomes univoltine at the higher elevations where the growing season is shorter and fewer heat units (above 10oC) are available for development. Long-term temperature records from the lower Hood River Valley indicate that the 25 years since 1985 have been considerable warmer than the 25 years prior to 1985. For instance, the average heat units available for codling moth development over a season have increased by more than 10% over the last 25 years. The codling moth is adapting to this warming trend by gradually increasing its voltinism (number of generations). As a result, the severity of codling moth as a pest can be expected to increase. Therefore, fruit growers will have to adjust and intensify control practices to keep fruit free from codling moth damage. We will also explore how other fruit and foliage feeding pests which are part of the pest complex of pears and apples in northern Oregon fare under different global warming scenarios compared to codling moth.

According to the IPCC report (IPCC, 2001), the global-mean surface temperature has risen by 0.6 oC during the 20th century due to the increase of atmospheric concentrations of greenhouse gases, and the mean temperature of the Korean Peninsula is also risen by 1.5 oC during the same period due to global warming as well as rapid urbanization. During the 21st century, the global-mean temperature is projected to rise 1.5-5.8oC associated with the various scenarios from IPCC Special Report on Emission Scenario (SRES) (2000). Climate change is expected to have important impacts on the relationship between crops and insect pests as well as on human societies. Frazier et al. (2006) demonstrated that warm-adapted insect species have much higher maximum population growth rate (intrinsic rate of increase) than do cold-adapted species; which indicates biochemical and physiological adaptations of insects do not overcome the constrain of thermodynamics. Consequently, global warming could lead to an increase in the number of insects worldwide. This presentation will discuss the changes in the population abundance of several citrus pests according to global warming. The differences of population growth rates between normal year's or past temperatures and elevated temperatures were compared, and also analytical models such as matrix model and predator-prey model were applied to project the performance of population dynamics of some pests and natural enemy.

The study investigated occurrence of major insect pests and damage to 16-30 representative apple orchards in major apple production area of 4-8 cities and counties in Gyeongsang Provinces and Jeonbuk province for 17 years from 1992 to 2008. In addition, it examined the hatching time of the overwintered eggs of European red mite (Panonychus ulmi) and apple leaf-curling aphid (Myzus malisuctus) at the Apple Research Station in Gunwi-gun, the Gyeongbuk Province from 1993 to 2009, and conducted a survey on the occurrence rate of oriental fruit moth (Grapholita molesta) and peach fruit moth by means of sex pheromone traps at 2-5 day intervals to look into the changes in the occurrence. As the result of survey on the insect pests of representative apple orchards, the population density of two spotted spider mite (Tetranychus urticae) was higher then that of Panonychus ulmi from 1992 to 1999 while it became lower than Panonychus ulmi from 2000. Although there was difference in spiraea aphid (Aphis citricola) by year, but the occurrence density tended to decline from 1992. Lyonetia prunifoliella had not become a problem in apple orchards before the 1990’s, but it started occurring in 1993-1994 and increased rapidly in the late 1990’s. Later, it has consistently increased as leafminer with Phyllonorycter ringoniella in apple orchards. Tortricid insect pests increased the most highly in the late 1990’s, but it has not been a problem after 2000 and the occurrence and damage by Grapholita molesta was higher than that of Carposina sasakii in apple orchards after 1997. Besides, the damage by stink bugs as well as ambrosia beetles has increased after 2000. In the 2000’s, the initial hatching date of overwintered eggs of Panonychus ulmi and Myzus malisuctus ulmi was 18 and 14 days earlier, the 50% hatching date was 7 and 6 days earlier, and the final hatching date was 1 and three days earlier respectively than that of the 1990’s. In the 2000’s, the first occurrence of Grapholita molesta and Carposina sasakii was earlier by 5 days compared to the 1900’s, and the first occurrence of apple insect pests tended to become earlier compared to the 1990’s.