The lowest temperature in Seoul yesterday was 18.7 degrees Celsius and the highest was 29.7. Day temperature differences of more than 10 degrees Celsius make people feel that a one-degree difference is nothing peculiar. For the entire planet, however, this means significant change. British environmental activist and author Mark Lynas vividly illustrated such changes in his book Six Degrees. A one degree rise in the atmosphere devastates granaries of the world, destroys coral reefs, and melts permafrost in polar regions, leading to rising sea levels around the world.
In this context, many were shocked by the news that temperatures worldwide have risen about 0.7 degrees over the past century. Scientists have presented projections of rise in temperatures. The Intergovernmental Panel on Climate Change, however, said in its fourth report on climate change in 2007 that temperatures will increase within a range of 1.1 to 6.4 degrees by 2100.
When volcanic dust covered the earths atmosphere after major volcanic eruptions in Indonesia 70,000 years ago, temperatures around the world plummeted. Because of this, the world population dropped to 15,000 to 40,000, according to scientists. Some 18,000 years ago when the last Ice Age came, the earth was colder than now by six degrees. As evidenced by traces of glaciers at Central Park in New York, North America was covered in ice at the time. This was the situation when temperatures dropped six degrees Celsius. What will happen when world temperatures rise that much is beyond scientific assumptions.
World leaders at the G8 summit, in which President Lee Myung-bak is also participating, have agreed to keep the world average temperature from rising more than two degrees from a century ago. Some criticize the agreement as lacking binding power and action plans to curb greenhouse gas emissions. Opposition from China and India for passing the responsibility of greenhouse gas emissions on to developing countries is also casting clouds over the path to a cleaner planet. According to Lynas, a two-degree rise in the average world temperature will change the nature of the monsoon climate that brings abundant rainfall, leading to widespread drought and more elderly people dying of heat in homes with no electricity due to disruption of hydroelectric plants. As horrible as the consequences of the two-degree rise are, humans will be relieved if the temperature rises only two degrees.
Editorial Writer Chung Sung-hee (chung@donga.com)