In this blog post, we’ll examine the causes and effects of global warming, as well as the measures we can take to address it.
Over the past few decades, global warming has established itself as one of the most critical environmental issues worldwide, alongside extreme weather events and climate change. The MBC documentary *Tears of the Arctic* showed just how rapidly the Arctic’s natural environment is changing due to global warming, raising awareness of the climate crisis among many people. So, what exactly is global warming—this phenomenon that poses a serious threat to the Earth we live on today?
Global warming, as the term suggests, refers to the phenomenon of the Earth gradually getting warmer. Scientifically, it refers to the long-term rise in the average temperature of the atmosphere and oceans near the Earth’s surface. The key concepts here are “average temperature” and “long-term rise.” Average temperature does not refer to the temperature at a single hour or day, but rather the average value of temperatures observed in a specific region over a certain period; a long-term rise refers to an upward trend lasting at least 10 years, not a short period such as 1–2 years.
Based on observations to date, analysis shows that the Earth’s average temperature has risen by more than 1.3°C compared to pre-industrial levels (1850–1900), and the rate of warming has accelerated in recent decades. Furthermore, the Intergovernmental Panel on Climate Change (IPCC) has indicated that, depending on future greenhouse gas emission levels, average temperatures could rise even further by the end of this century. This persistent rise in temperature has raised concerns that climate change could have serious impacts on human society and ecosystems. A prime example is the movie *The Day After Tomorrow*, which dramatically depicts the extreme disasters that could result from climate change and served as a catalyst for many people to recognize the severity of the climate crisis.
Although various studies have been conducted on the causes of global warming, the most widely accepted cause is the greenhouse effect caused by greenhouse gases. Most of the energy reaching Earth from the Sun is in the form of visible light, and this energy heats the Earth’s surface. The heated surface then emits energy in the form of infrared radiation, which is absorbed by greenhouse gases in the atmosphere, such as water vapor and carbon dioxide. The absorbed energy is re-emitted back toward the Earth’s surface and the atmosphere, partially preventing heat from escaping into outer space. As a result, the temperature near the Earth’s surface remains higher than that in the upper atmosphere.
This temperature-raising effect caused by water vapor, carbon dioxide, and other greenhouse gases in the atmosphere is called the greenhouse effect, and it is a natural phenomenon essential for the survival of life on Earth. However, the current problem is not the natural greenhouse effect, but rather the greenhouse effect that has been amplified by human activities. Since the Industrial Revolution, the use of fossil fuels has increased dramatically and forests have been destroyed on a massive scale, leading to a significant rise in the concentration of greenhouse gases—particularly carbon dioxide—in the atmosphere. The most widely accepted explanation today is that, as a result, more heat that should be released into space is being trapped in the atmosphere, causing the Earth’s average temperature to rise continuously.
The Earth’s ongoing temperature rise and the resulting climate change are having a massive impact on human life and industry as a whole. First, rising average temperatures lead to sea-level rise. Currently, the primary causes of sea-level rise are thermal expansion of seawater and the melting of glaciers and ice sheets. As seawater warms, its volume expands, raising sea levels; additionally, the melting of the Antarctic and Greenland ice sheets, as well as glaciers around the world, increases the volume of seawater. Given that a significant portion of the world’s population lives in low-lying coastal areas, even a slight rise in sea level can result in massive damage. Delta regions and low-lying coastal areas, in particular, are at high risk of flooding, with countries such as Bangladesh considered prime examples of vulnerable regions. Furthermore, seawater intrusion can increase the salinity of groundwater used for agriculture, significantly impacting agricultural production.
Climate change also has a direct impact on agriculture and food supply. Appropriate temperatures and precipitation are essential for growing specific crops, yet these two factors are changing significantly due to global warming. Yields of some crops decline in high temperatures, and changes in precipitation can severely affect agricultural production in arid regions. Furthermore, as extreme weather events such as droughts and torrential rains become more frequent, water supplies may become unstable and soil conditions may deteriorate. These changes are likely to further widen the gap in agricultural productivity between countries, and the risk of food shortages and hunger may increase, particularly in developing countries.
Ecosystems are also significantly affected by climate change. Plants and animals that have adapted to consistent temperatures and precipitation levels find it difficult to adapt quickly to rapid climate change or to relocate their habitats. While humans can respond to environmental changes using technology and transportation, many species cannot. As a result, the balance of existing ecosystems is disrupted, and the likelihood of damage from diseases and pests increases.
Trees, in particular, have very long lifespans and are highly sensitive to climate change. Even a change of just 1°C in the annual average temperature can lead to significant differences in growth and productivity, and trees that fail to adapt to the changed environment may become even more vulnerable to pests and diseases. This has a major impact not only on forest ecosystems but also on the forestry industry. Furthermore, since forests are important carbon sinks that absorb carbon dioxide, a decline in forest health can also weaken their ability to mitigate climate change.
Marine ecosystems are no exception. Corals in tropical and subtropical regions are highly sensitive to changes in sea surface temperature. Even a rise of just about 1°C above the long-term average can trigger coral bleaching, and if this phenomenon persists for an extended period, there is a risk that large-scale coral reefs will disappear. In fact, coral bleaching events are occurring repeatedly in various regions around the world, and many scientists are concerned about the continued deterioration of marine ecosystems.
Coral bleaching refers to the phenomenon in which coral tissue is damaged, causing the symbiotic algae to disappear and exposing the calcareous skeleton, which turns white.
Finally, global warming has a direct impact on human health. Record-breaking heat waves have been recurring around the world recently, and extreme heat goes beyond mere discomfort—it can increase the incidence of heatstroke, cardiovascular diseases, and respiratory illnesses, and even raise mortality rates. The elderly and those with underlying health conditions are particularly vulnerable to heat waves. Furthermore, rising temperatures expand the range of vectors such as mosquitoes, raising significant concerns about the potential spread of infectious diseases like malaria and dengue fever.
As such, global warming is not merely an environmental issue but a critical challenge directly linked to the future of all humanity. While diverse opinions still exist regarding the causes and impacts of climate change, there is broad consensus within the international community that human activities are accelerating climate change and that efforts are needed to mitigate it. To solve this global problem, cooperation among the international community and efforts by governments, businesses, and the scientific community are essential. However, what matters most is individual action. John Brown, former CEO of the global energy company BP, stated, “No single company or country can solve the problem of climate change on its own. However, constructive actions by each of us can certainly bring about meaningful change.” The steps individuals can take are already well known. Typical examples include improving energy efficiency, reducing the use of fossil fuels, and adopting lifestyle habits that cut greenhouse gas emissions. In the face of a changing global environment, the measures we adopt and the actions we take ultimately depend on the choices we all make.
