In this blog post, we examine the reality of sea level rise and extreme weather events caused by global warming, and consider practical responses individuals and society can take to prevent them.
You may have seen public service announcements featuring images of polar ice caps melting like ice cream on a hot day, accompanied by warnings about rising sea levels. “Even if most of our island is submerged by seawater, we will not leave our land. We must prevent that from happening.” These are the words of the Prime Minister of Tuvalu. Tuvalu, a small Pacific island nation often cited as a prime example of damage from global warming, has already seen significant portions of its land submerged due to rising sea levels. Today, global warming is identified as a major driver of numerous weather anomalies, including sea level rise, and has become a major societal issue. Let’s take a closer look at global warming.
‘Global warming’ refers to the long-term rise in surface temperatures near the Earth’s surface. First mentioned in the 1972 Club of Rome report, it gained significant attention in 1985 when the World Meteorological Organization and the United Nations Environment Programme asserted that ‘the greenhouse effect caused by increased carbon dioxide concentrations is the cause of warming’. Many experts predict that if warming continues, irreversible disasters will occur, and they point to global warming as the cause of recent extreme weather events. Currently, under the consensus that humanity must stop warming, numerous international agreements and cooperative organizations have been launched, and various campaigns are being implemented.
In fact, since its formation, Earth has cycled through cold ice ages and warm interglacial periods. While the current interglacial period naturally involves rising global temperatures, the excessive magnitude of this increase is problematic. Since weather observations began, Earth’s average temperature fluctuated until the 1970s, but has shown a distinct upward trend since the 1960s. The average temperature increase over the past 50 years has been 0.13°C per decade, roughly double the rate of the previous century (0.07°C per decade). The last decade was the hottest on record, and the rate of temperature increase is projected to continue accelerating.
The necessity of preventing global warming stems from the fact that human activities are the primary cause of increased greenhouse gases. Gases causing the greenhouse effect include water vapor, carbon dioxide, methane, chlorofluorocarbons (well-known as CFCs), and nitrous oxide. Concentrations of all these gases can be heightened by human activities, and observational data indicates their concentrations are trending significantly upward. If greenhouse gases continue to be released into the atmosphere at the current rate, it is projected that the global average temperature will rise by approximately 3°C by around 2040 compared to current levels. In the worst-case scenario, it has been concluded that by the end of the 21st century, the environment could become inhospitable for human life. While there is some debate about whether the greenhouse effect is the primary cause of global warming, the prevailing opinion is that reducing greenhouse gas emissions will mitigate warming.
A primary damage expected from global warming is sea level rise. While melting glaciers floating on seawater do not directly affect sea level, melting glaciers on land flowing into the ocean cause sea levels to rise. Additionally, changes in seawater density due to rising temperatures also contribute to sea level rise. The Intergovernmental Panel on Climate Change (IPCC) predicts a sea level rise of 110 to 880 mm by the end of the 21st century. Such a rise would force many people living in low-lying coastal areas to relocate to higher ground, and most small island nations could disappear from the Earth. If warming continues and Greenland’s ice sheets melt, sea levels could rise by over 6 meters, a level sufficient to submerge most coastal cities.
Furthermore, extreme weather events are also considered a major consequence of global warming. As the Earth’s temperature rises, sea temperatures also increase, making low-pressure systems more likely to form with greater intensity. For example, Typhoon Rusa dumped 870mm of rain on the Gangneung region in a single day, breaking the record for daily rainfall, and caused over 5 trillion won in property damage. Typhoon Maemi caused over 130 fatalities nationwide and property damage exceeding 4.7 trillion won. Global warming also alters precipitation patterns, leading to flooding in one area while causing water shortages and related damage in another. Precipitation has increased in mid- and high-latitude regions like North and South America’s eastern coasts, Northern Europe, and Northern Asia. Conversely, precipitation has decreased in low-latitude areas such as the Sahel, the Mediterranean, South America, and South Asia. An example is Lake Chad, once the world’s sixth-largest lake, which has shrunk due to evaporation caused by drought. The frequency and duration of El Niño and La Niña events have also increased, closely linked to the rise in global temperatures. Rising temperatures mean increased energy; a warmer Earth holds more energy, leading to faster water circulation and causing extreme weather events.
So, what is the solution to prevent global warming? Simply put, it is ‘reducing greenhouse gases’. If global warming is caused by human activity, it is likely due to the greenhouse gases emitted by humans. Additionally, the increased concentration of carbon dioxide caused by deforestation is also one of the causes. While practical solutions have been lacking so far, there are actions individuals and communities can take.
At the individual level, solutions include, first, conserving energy and resources. Various methods are possible, such as saving electricity at home, using public transportation, and conserving water. Using environmentally friendly products is also a good approach. For example, using high-efficiency appliances or products that generate less waste. If such consumption patterns become established, producers will also consider them when manufacturing products, potentially leading to a long-term shift in the economic structure itself towards being more environmentally friendly. In the same vein, making recycling a part of daily life is also effective. Incinerating waste produces significant amounts of methane gas, so reducing this is a major achievement. Additionally, planting and nurturing trees, which are carbon dioxide sinks, is another action individuals can take. Countries rich in forests, like those in Northern Europe, absorb large amounts of carbon dioxide, reducing their burden for greenhouse gas reduction.
At the community level, the Kyoto Protocol regulates greenhouse gas emissions, but its implementation faces difficulties due to political and economic interests among participating nations. To reduce greenhouse gases without international conflict, ‘alternative energy development’ is essential. While various alternative energies are currently researched and used, their high costs make them difficult for consumers to adopt easily. The solution lies in developing ways to commercialize alternative energy at low cost.
We have examined global warming, its causes, and countermeasures. Warming is the phenomenon of rising global temperatures, a critical issue that could inflict immense damage on humanity if sustained. If meteorologists’ analyses are correct, we must pay greater attention to global warming and strive to prevent it. While humanity has developed by harnessing nature thus far, it may now be time to move toward living in harmony with nature.
