The Korea Meteorological Administration has forecast the beginning of the summer monsoon season this year, but said it will not predict the end of that season in its weather forecast for this year. It has become meaningless to predict the end because there is such a strong possibility of continued heavy rains afterwards. Until last year, the KMA used to announce when the monsoon season would start and end.
In the past, summer weather in Korea was characterized by rain across the nation for about a month starting at the end of June, as the seasonal rain front moves into the Korean Peninsula, which was usually followed by scorching hot temperatures in August and occasional showers. But recently, there has been an increase in torrential downpours in August. Between 1941 to 1970, the average amount of rainfall in Korea's seven major cities during August was 220 mm. But between 1971 to 2007, that amount increased to 307 mm. Last year, the KMA forecast the summer monsoon season to end in the latter half of July. But we saw many days of torrential downpours in the central part of the Korean Peninsula during August.
Meteorologists believe Korea is witnessing a rainy season throughout the summer as the country's climate turns subtropical, with global warming raising the amount of water vapor in the atmosphere. The "August rains" often cause a substantial amount of damage, since torrential downpours are focused on a small area over a short period of time. Between 1954 and 1963, only an average of 1.6 days a year saw 80 mm of rainfall a day. But that increased to 2.3 days between 1994 and 2003. The torrential downpour phenomenon is becoming a feature of our weather. Global warming increases the amount of energy in the atmosphere, leading to more frequent extreme weather conditions, such as typhoons.
Korea's ecosystem is also witnessing a major change. Until the 19th century, golden bamboo was found only in the southern region. But now, its habitat has moved up to 100 km north to the Sobaek Mountain Range and Yecheon, North Gyeongsang Province. Pear and persimmon farms are also moving north, while spring flowers bloom around 20 days earlier than before, leading to damage from harmful insects. Another sign that we are changing to a subtropical climate is that rising temperatures in the ocean are leading to an increase in types of fish found in warm currents.
In February last year, the Intergovernmental Panel on Climate Change said the average temperature on Earth rose 0.74 degrees over the past 100 years and will rise another 1.1 to 6.3 degrees further over the next century. The problem is that over the past 100 years, the average temperature on the Korean Peninsula rose 1.5 degrees, making the region experience far more violent weather changes than the average around the world. Disaster and weather officials must be ready with watertight response measures at all times.