Global warming has accelerated since the industrial revolution due to the rapid increase in greenhouse gas emissions, which is causing natural disasters and ecosystem changes that are having a major impact on society and the economy. The international community is making various efforts to combat this, but it requires the active participation of citizens around the world.
Global warming refers to the increase in the average temperature of the Earth’s surface. While warming has occurred in the past, global warming primarily refers to the warming observed since the Industrial Revolution. This is because the causes of past warming and post-industrial warming are different: past warming was a natural phenomenon that occurred as the Earth’s average annual temperature rose and fell in a 400-500 year cycle. Post-industrial warming is warming caused by human activity, as the rapid increase in fossil fuel use has altered the climate system, reducing the amount of radiant heat that escapes from the Earth.
The main cause of global warming is known as the greenhouse effect caused by greenhouse gases. Insolation energy from the sun to the Earth travels through the atmosphere, reaches the Earth’s surface, and is radiated back into the atmosphere. The radiated energy is absorbed by water vapor and greenhouse gases such as carbon dioxide in the atmosphere. This causes more of the radiated energy to stay near the Earth’s surface than in the upper layers of the atmosphere, causing the temperature to rise. This results in the Earth’s surface temperature being higher than it would be without an atmosphere, given the same amount of insolation. This phenomenon is known as the greenhouse effect.
The greenhouse effect can be easily understood by analogizing it to a greenhouse. The vinyl covering the greenhouse lets light in and keeps heat out. The light enters through the plastic and heats the inside of the house, but the heat cannot escape through the plastic. The temperature inside the greenhouse continues to rise, and the plastic covering the greenhouse acts like a greenhouse gas. Just as thicker vinyl increases the temperature inside the house, an increase in greenhouse gases in the atmosphere increases the temperature at the Earth’s surface.
Greenhouse gases that cause the greenhouse effect include water vapor, carbon dioxide, methane, and freon gas. Water vapor is water that has evaporated from oceans, lakes, and the Earth’s surface, so it doesn’t have much of an effect on the greenhouse effect. GHGs like carbon dioxide, methane, chlorofluorocarbons, and nitrogen, on the other hand, directly affect the greenhouse effect. Methane from the burning of fossil fuels, fires in tropical forests, livestock breeding, and agricultural expansion, freon gas used as a refrigerant, pesticide, and cleaning agent, and nitrogen from chemical fertilizers have been increasing rapidly in recent years, and the greenhouse effect caused by these gases is also increasing. Among these, carbon dioxide has the highest concentration and contributes the most to the greenhouse effect.
Global warming is causing extreme weather events, resulting in natural disasters such as rising Arctic and Antarctic temperatures, shrinking glaciers, floods, droughts, and rising sea levels. These natural disasters are not only impacting the environment, but also society and the economy. As the average global temperature rises, natural ecosystems are changing, including earlier blooming of trees, earlier spawning of birds, changes in habitat for insects, plants, and animals, increased bleaching of coastal areas, and decreased biodiversity. In addition, the frequency of natural disasters is increasing, and the number of deaths from them is steadily rising, and diseases that are strongly linked to climate change, such as malaria, bacterial dysentery, and tsutsugamushi, are also increasing, threatening human health. Global warming is also changing the supply and demand of markets, negatively impacting industries such as energy and transportation.
According to the IPCC, an organization that specializes in climate change research, without international efforts to reduce greenhouse gas concentrations, atmospheric temperatures are expected to continue to rise throughout the 21st century. According to the IPCC’s Fourth Assessment Report, global warming is expected to continue at a rate of about 0.2℃/10 years over the next 20 years. This is 210 times faster than the observed temperature rise over the past 100 years, and much faster than the changes over the past 10,000 years. The concentration of greenhouse gases in the atmosphere, currently around 368 parts per million (ppm), is expected to increase to 490 to 1,260 ppm in the 21st century, with a corresponding increase in global average temperature of about 1.4 to 5.8 degrees Celsius between 1990 and 2100. In addition, average sea level is projected to rise by 8 to 8.8 centimeters from 1990 levels during the 21st century, with the potential for low-lying areas, including Korea, to be submerged in seawater.
The international community has recognized the seriousness of global warming and is making efforts to prevent it. In 1985, the World Meteorological Organization and the United Nations Environment Programme declared that carbon dioxide is the main culprit of warming, and in 1988, the Intergovernmental Panel on Climate Change (IPCC) was formed to investigate and study climate change. The United Nations Framework Convention on Climate Change, adopted at the Rio Conference in Brazil in 1992, aims to stabilize greenhouse gas concentrations in the atmosphere to prevent extreme weather events caused by global warming. Recognizing that reduction obligations under the existing Convention were insufficient to prevent global warming, the first Conference of the Parties held in Berlin, Germany, in 1995, adopted the Kyoto Protocol, which outlines reduction targets for developed countries after 2000, at the third Conference of the Parties held in Kyoto, Japan, in 1997. The Kyoto Protocol is a legally binding international agreement to reduce greenhouse gases and sets specific targets for countries around the world to work toward preventing global warming.
The Korean government has also prepared and implemented policies to prevent global warming. A representative policy is the greenhouse gas emissions trading system. This system utilizes market mechanisms to allow the trading of GHG emission credits in order to achieve GHG reduction targets efficiently and at low cost. The system allows emitters to selectively utilize GHG reduction investments or purchase emission credits based on the carbon price, providing flexibility compared to direct regulation. In addition, the Korean government has introduced the Clean Development Mechanism, which allows developed countries to implement GHG reduction projects in developing countries and receive credit for the results. In addition, the government has introduced and operates a GHG and energy target management system, regulations on automobile fuel efficiency and greenhouse gases, and is striving to prevent global warming by establishing a GHG statistics system, fostering GHG management experts, promoting climate change-responsive R&D projects, and green living citizen movements.
As such, most countries around the world recognize the dangers of global warming and, like Korea, are making efforts to prevent it at the government level. However, government efforts alone are not enough to prevent global warming. Therefore, the international community is calling on citizens around the world to be concerned about global warming and take action to prevent it.
