The Alarming Reality of Wet Bulb Temperature and Climate Change
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Chapter 1: Understanding Wet Bulb Temperature
Wet bulb temperature is a crucial yet often overlooked aspect of climate change, significantly influenced by global warming. While discussions typically center on events like droughts, hurricanes, and unusual cold spells, the ramifications of rising heat levels are frequently neglected. This assumption—that humans can easily adapt to moderate temperature increases—has proven false, especially in regions with high humidity.
Wet bulb temperature is the key indicator that can make entire areas unlivable. It is defined as the temperature of a wet thermometer bulb, where evaporation cools the air around it. Unlike a dry bulb thermometer that measures ambient temperature, a wet bulb thermometer indicates the air temperature when humidity reaches 100%, at which point evaporation ceases.
To measure this, a device known as a sling psychrometer is utilized:
The sling psychrometer features two thermometers: one for dry temperature and another covered with a “sock” for the wet bulb reading. At 100% humidity, both readings match; otherwise, the wet bulb temperature is always lower. While dry climates may reach extreme temperatures, they are also conducive to evaporative cooling. Conversely, humid areas face a critical threshold where evaporative cooling becomes ineffective.
Section 1.1: The Human Body's Response to Heat
Humans and other warm-blooded creatures depend on heat dissipation through sweating, which involves releasing moisture. The human body maintains a temperature of 98.6°F (37°C) by allowing heat to escape through the skin via sweat. However, when humidity is high, sweat cannot evaporate, leading to overheating.
In fact, heat strokes have recently claimed lives, with a heatwave in the Pacific Northwest leading to 60 fatalities within days. The human body is at risk of death once internal temperatures reach 108°F (42°C), with vulnerable individuals succumbing even sooner.
Globally, around 700 heat stroke deaths occur each year in the United States alone, a nation where air conditioning is common. In contrast, the worldwide death toll from heat-related causes stands at approximately 300,000 annually, with a significant proportion linked to climate change. Without access to cooled environments, survival becomes nearly impossible in areas experiencing extreme heat and humidity.
Subsection 1.1.1: The Danger of High Wet Bulb Temperatures
While extremely high dry bulb temperatures are alarming, they primarily pose a risk in arid regions. These areas can offer shelter and survival until temperatures exceed 120°F (49°C). However, in humid climates, wet bulb temperatures in the mid-80s°F (26–32°C) can be lethal, especially for the elderly and those with health issues. Historical heatwaves in Europe and Russia exemplify this danger, with wet bulb temperatures around 82°F (27°C) causing significant fatalities.
Wet bulb temperatures that closely approach the human body's core temperature can lead to death within hours, even under shaded conditions or with a fan. Without a compressor-based air conditioning system to cool and dry the air, survival becomes impossible. A wet bulb temperature of 95°F (35°C) is incompatible with human life.
Chapter 2: The Increasing Threat of Wet Bulb Temperature
The concerning reality is that the occurrence of high wet bulb temperatures has risen over the last four decades due to global warming. Areas from India to the Middle East and Australia are experiencing this phenomenon, often in sparsely populated regions. However, should such temperatures strike densely populated areas for extended periods, the consequences could be catastrophic, akin to a major disaster.
Billions of People at Risk from Wet Bulb Temperature's Rendering Major Cities Uninhabitable - YouTube
This video discusses the alarming implications of rising wet bulb temperatures and their potential to make major urban areas uninhabitable, with thousands of lives at stake.
Moreover, regions that regularly experience extreme wet bulb temperatures would become virtually unlivable, as the local populace could not endure such conditions without adequate cooling systems. Prolonged exposure to high wet bulb temperatures could decimate populations of both humans and animals.
The consequences of this trend are dire: populations will need to migrate to cooler areas, potentially sparking significant refugee crises. Alarmingly, increases in wet bulb temperature intensity and duration are occurring decades ahead of previous predictions, signaling that existing climate change mitigation efforts may be insufficient.
Wet Bulb Temperature: Life or Death? - YouTube
This video explores the critical issue of wet bulb temperature and its implications for human survival in a rapidly changing climate, emphasizing the urgent need for awareness and action.
The world must adapt by relocating entire communities. Cities in regions such as China and South Asia may face abandonment without adequate cooling infrastructure. The most severely impacted areas may not be in the southernmost regions but rather those with high humidity, particularly coastal zones.
This shift necessitates increased investments not only in emission reduction but also in adapting to current challenges. While constructing barriers against rising seas is critical, it is equally essential to develop strategies for surviving extended periods of extreme heat. Even with a shift to complete carbon neutrality, the oceans will continue to release heat for decades, making it crucial to slow the trend of rising temperatures and protect vulnerable populations from devastating heat events.