In this blog post, we will examine the primary causes of global warming—such as the increase in greenhouse gases due to industrialization and deforestation—and explore the various threats that humanity and the natural environment face as a result.
According to climatology, global warming refers to the phenomenon of rising temperatures near the Earth’s surface. The term “global warming” as used today refers to the rise in temperature caused by the increase in greenhouse gases resulting from industrialization that began in the 1970s.
The causes of global warming can be broadly divided into natural causes and those resulting from human industrial activities. First, we will examine the natural causes of global warming. While long-term research and observation are necessary to identify natural causes, it is difficult to fully elucidate them since the international community has been aware of the global warming issue for less than 40 years. Although the research period has been short, current findings suggest that changes in the Earth’s axis of rotation affect its orbital path, altering the area exposed to solar energy and thereby contributing to global warming. Additionally, the types of gases emitted during volcanic eruptions and the scale of the eruptions can also influence global warming. While some argue that changes in solar activity raise the Earth’s average temperature, this remains a subject of debate.
The causes mentioned in the previous paragraph are merely secondary factors; according to current research, human activities appear to be the primary cause of global warming. Anthropogenic factors can be broadly divided into two categories: the increase in greenhouse gas concentrations due to industrial development and the slowing of greenhouse gas purification caused by indiscriminate deforestation. First, let us examine the process by which greenhouse gas levels have risen due to industrial development. Since the Industrial Revolution, the use of fossil fuels has surged, leading to increased concentrations of greenhouse gases such as carbon dioxide and methane, which has accelerated global warming. When fossil fuels are burned to generate energy—whether to power engines or generate electricity—the carbon-containing fuels react with oxygen to produce carbon dioxide. Furthermore, as various modes of transportation developed, the use of automobiles surged, significantly contributing to the rise in greenhouse gases. While greenhouse gases originally play a necessary role in maintaining the Earth’s temperature, their rapidly increasing concentrations prevent some solar radiation from escaping into space, abnormally raising the Earth’s average temperature.
Additionally, land use patterns changed drastically around the 1970s. Land that had been used primarily for crop cultivation until the 1960s saw its forests cleared due to changes in land use driven by industrial development. For example, a significant portion of the Amazon rainforest—often referred to as the “lungs of the Earth”—has already been lost. The reason we focus on these land-use changes is that plants and trees absorb carbon dioxide, a greenhouse gas in the atmosphere, through photosynthesis and convert it into oxygen. When forests disappear, it is not merely a matter of losing carbon dioxide; the reduction in photosynthesis—the process that converts carbon dioxide into oxygen—leads to a rise in greenhouse gas concentrations.
Thus, due to rapid industrial development and indiscriminate land development, global warming has reached a critical level. Global warming goes beyond simply raising temperatures and causing inconvenience in daily life; it threatens human life in three major ways. First, let’s examine changes in the Earth’s topography. To date, global warming has been progressing more rapidly in high latitudes than in low latitudes. In particular, as warming accelerates in high latitudes, glaciers in those regions are melting, causing sea levels to rise. As a result, one-third of the coral reef islands in the Pacific are expected to be submerged. In fact, two islands located in India’s Sundarbans National Park, a site of significant global cultural heritage value, have already been submerged due to rising sea levels.
Second, natural disasters caused by global warming are becoming severe. As the Earth’s average temperature rises, sea surface temperatures are also increasing, which in turn boosts the energy stored in the oceans, making typhoons and hurricanes more intense. According to a study by the Massachusetts Institute of Technology, the intensity of typhoons and hurricanes has increased by about 50% since the 1970s. In fact, in 2005, Hurricane Katrina struck New Orleans, killing 1,500 people and displacing 800,000. In South Korea, Typhoon Rusa in 2002 caused property damage exceeding $3.6 billion, and Typhoon Maemi in 2003 inflicted damage equivalent to 1% of South Korea’s GDP. As sea surface temperatures—the primary factor influencing typhoon intensity—rise, large-scale typhoons are expected to become more frequent in the future. While global warming has led to an overall increase in precipitation, there are significant regional variations. While flooding and damage occur in some parts of the world, precipitation has decreased in regions such as the Sahel, the Mediterranean, and Southern Africa, and Lake Chad in Central Africa has dried up. While rising temperatures can lead to heavier rainfall due to increased seawater evaporation, they also cause soil moisture to evaporate, accelerating desertification.
Finally, in addition to the loss of islands due to desertification or sea-level rise, global warming has serious implications for ecosystems and human health. As the Earth’s average temperature rises, flora and fauna are gradually migrating to higher latitudes, and wildlife is facing extinction due to environmental changes. The extinction of species does not simply mean the disappearance of individual organisms; it affects the entire food chain and ultimately has negative consequences for humans as well. Furthermore, rapid temperature changes pose a direct threat to human health. According to the WHO, deaths caused by heatwaves and droughts are steadily increasing, and water shortages are expected to become even more severe. As temperatures rise, the range of disease-causing bacteria and the insects that transmit them is expected to expand, leading to an increase in the number of deaths. In fact, in Africa, temperatures have risen steadily over the past 30 years, leading to an increase in the mosquito population and a rise in malaria incidence.
Currently, global warming is far more severe than we realize. To address this, the international community is making efforts to reduce greenhouse gas emissions through various agreements. The “United Nations Framework Convention on Climate Change” is an international environmental agreement aimed at curbing greenhouse gas emissions, which are the primary cause of climate change; it was officially adopted at the 1992 Rio Earth Summit. However, since this convention was merely a mutual commitment and therefore non-binding, the Kyoto Protocol was signed to supplement it. The Kyoto Protocol is a substantive agreement for reducing greenhouse gas emissions, setting a target for developed nations—which led the Industrial Revolution—to reduce emissions by an average of 5.2% compared to 1990 levels. Looking at trends in international climate change negotiations, developed countries have set a reduction target of 25–40% compared to 1990 levels, while developing countries have set a target of 15–30% compared to business-as-usual (BAU) levels, in order to limit the rise in temperature to within 2 degrees Celsius.
Given the severity of global warming, not only are immediate reduction policies necessary, but adaptation policies are also required to address existing problems and prepare for future crises. The environment does not belong exclusively to humans; for the sake of future generations, the problem of global warming must be resolved.
