South Korea's summers increasingly resemble those of Southeast Asia, characterized by high humidity, scorching sunlight, and sudden downpours. The landscape of midsummer is no longer the familiar temperate climate. The troubling aspect of this change is that it does not affect everyone equally.
Disasters always strike unevenly. For farmers, construction workers, delivery drivers, and elderly individuals living alone, heat waves are not just uncomfortable weather; they pose a life-threatening disaster.
According to the Korea Meteorological Administration, from June 1 to July 27, the average number of tropical nights across the country was 7.8 days, the highest since nationwide observations began in 1973. The average temperature was also 24.2 degrees Celsius, the second highest on record. The overlapping of the North Pacific High and the Tibetan High has trapped hot, humid air over the Korean Peninsula, with daytime highs expected to reach between 33 and 39 degrees Celsius from August 1 to 7. In Yangsan, South Gyeongsang Province, nighttime temperatures did not drop below 29.1 degrees Celsius.
The damage is already evident in the numbers. On July 27, the government raised the heat wave warning to the highest level, 'serious,' and activated the Central Disaster and Safety Countermeasures Headquarters.
As of that date, there were 1,399 reported cases of heat-related illnesses, with an estimated eight fatalities. More than 80% of patients collapsed outdoors, with the majority of incidents occurring at workplaces. While heat waves may be a painful commute for office workers, they are a matter of life and death for outdoor laborers and the elderly.
'Human Refrigerators' Emerge
In neighboring Japan, days with temperatures exceeding 40 degrees Celsius are referred to as 'gokushobi' (酷暑日), literally meaning 'brutally hot days.' Climate change is not only creating new weather patterns but also new terminology.
On July 21, temperatures in Kihoku and Toyota, Aichi Prefecture, surpassed 40 degrees Celsius, with five consecutive days of temperatures above 40 degrees recorded. Between July 13 and 19, approximately 11,000 people were transported to emergency care for heat-related illnesses, with 14 already deceased upon arrival at hospitals.
In Japanese industrial settings, cooling booths called 'Dohiemon boxes' have emerged, allowing one adult to enter and cool down. These 'human refrigerators' maintain an internal temperature of about 15 degrees Celsius and blow cool air at around 5 degrees Celsius onto the head, neck, shoulders, and back. High school baseball games have been rescheduled to avoid the hottest times of the day, and farmers are testing subtropical crops like heat-resistant rice and avocados. This is a survival manual for the era of global warming.
In Europe, disasters continue even after heat waves pass. In France, an estimated 5,764 excess deaths occurred during the heat wave from June 17 to July 2. High temperatures rapidly depleted moisture from soil, rivers, lakes, and plants. As the ground dries, much of the solar energy is used to heat the surface and atmosphere rather than evaporating moisture. This creates a vicious cycle where heat causes drought, and drought exacerbates heat.
European grain production is expected to decrease by about 9 million tons this year, and the lowering water levels in the Rhine, Loire, and Danube rivers threaten logistics and hydropower generation. Researchers from the World Meteorological Organization have analyzed that extreme evaporation conditions have become about 80 times more likely in Western Europe and about 40 times more likely in Eastern Europe due to climate change.
Scholars do not view this heat wave as a mere anomaly or natural phenomenon. While natural atmospheric flows may be a direct cause, the underlying factor is human-induced climate change.
James Renwick, a climate scientist and professor at Victoria University of Wellington in New Zealand, stated in an interview with Aju Business Daily, 'The extreme heat waves occurring around the world, including in Korea, are difficult to explain without climate change.'
He explained that while heat waves have occurred in the past, the current situation is different. Even a slight increase in the Earth's average temperature leads to more frequent, longer-lasting, and more intense heat waves. He noted that a rise of just 1 to 1.5 degrees Celsius significantly increases the likelihood of extreme heat events.
Ashish Sharma, a professor at the University of Illinois, likened this to 'changing the dice.' While heat waves existed before, climate change has altered the dice itself. Now, even when rolling the same dice, the probability of extreme heat outcomes has significantly increased.
While atmospheric phenomena like high pressure or blocking are direct triggers for heat waves, global warming amplifies their intensity and duration.
Shang-Ping Xie, a professor at the University of California, San Diego, described this heat wave as a typical example of a blocking phenomenon. When a strong high-pressure system lingers over an area, the air continues to descend, compressing and heating up. Simultaneously, reduced cloud cover and rainfall allow strong sunlight to continuously heat the surface. Without rain, the parched ground cannot cool down and instead releases more heat into the atmosphere. Additionally, warmer-than-average waters in the Yellow Sea and East Sea provide extra heat and moisture, resulting in tropical nights where temperatures do not drop.
Professor Xie stated, 'The foundation of all these phenomena is the slow but relentless warming created by greenhouse gases.'
Of course, science is cautious. To determine exactly how many times more frequently or intensely this heat wave occurred due to climate change, 'climate attribution' studies are necessary. This involves comparing a hypothetical Earth where humans have emitted little to no greenhouse gases with the actual Earth to calculate how much human activity has influenced specific heat waves.
However, the scientific consensus is that the lack of completed attribution studies does not negate the connection between human activity and heat waves.
Dargan Frierson, an atmospheric scientist at the University of Washington, remarked, 'The Earth has already changed significantly due to fossil fuel emissions,' adding, 'It is virtually impossible to find weather phenomena that are completely unrelated to pre-industrial climate.'
He further noted, 'The immense heat energy generated by fossil fuels is accumulating in the atmosphere and oceans, causing heat waves to occur more frequently, last longer, and be more extreme.'
Natural climate variability also plays a role. Francina Dominguez, a professor at the University of Illinois, explained that strong El Niño events and global warming can interact to alter global atmospheric circulation.
However, experts agree that while El Niño may influence when and where heat waves occur, greenhouse gases continue to raise the baseline for when these heat waves happen.
Ultimately, even the same high-pressure systems result in hotter summers now than in the past.
Experts predict that as long as greenhouse gas emissions continue, heat waves will become more frequent, more intense, and last longer.
Professor Frierson warned, 'The more fossil fuels we burn, the more extreme heat waves will occur.'
Professor Renwick cited an analysis from the UK Met Office, suggesting that disasters on the scale of the 2003 European heat wave, which claimed over 70,000 lives, could recur approximately every two years by 2050, stating, 'As greenhouse gas emissions increase, both the changes and the damage will also grow.'
Professor Xie added, 'Climate models have been warning of futures like this for decades,' noting that the recurring heat waves and large wildfires worldwide demonstrate that these predictions are becoming reality.
Experts unanimously agree that heat waves are no longer exceptional weather anomalies but are becoming the new normal due to human-induced climate change. While the timing and location of heat waves may be determined by natural atmospheric flows, their intensity and frequency will increase as greenhouse gases accumulate. Ultimately, the current heat wave is not a temporary anomaly but a preview of a future that will repeat itself.
* This article has been translated by AI.
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