Heat waves are occurring more than they used to all over the world. A recent data suggest that the number of heat waves have and exponential growth as compared to those before 2000s due to which Over 600 individuals each year on average died from 1999 to 2009.
What is heat wave ?
A heat wave is a persistent period of abnormally high surface temperatures in comparison to what is typically anticipated. Heat waves are major contributors to weather-related mortality that can last for several days to many weeks and affect both industrialized and developing nations. Globally, during the 1950s, heat waves have become more frequent and more intense, and this has been linked to climate change. Low humidity, which can make droughts worse, or high humidity, which can make heat-related illnesses such heat exhaustion, dehydration, and heatstroke worse, characterize such climatic phenomena.
A heat wave has had no actual definition that is standardized. The World Meteorological Organization defines it as five or more days in a row where the daily maximum temperature is 5 °C (9 °F) or higher over the average maximum temperature. Some nations have their own standards that they use. The U.S. National Weather Service defines a heat wave as a period of "abnormally and uncomfortably hot and unusually humid weather" lasting two days or more, in contrast to the India Meteorological Department's requirement that temperatures rise 5-6 °C (9-10.8 °F) or more above the average temperature.
What causes heat waves ?
When a system of high atmospheric pressure arrives into a region and lasts for many days, it causes a heatwave. In such a high-pressure system, air from the atmosphere's upper layers is drawn toward the surface, where it is compressed and heated. Because of the difficulty other weather systems have moving into the area due to the high pressure concentration, the heatwave may linger for several days or even weeks. The area gets hotter the longer the system is in place. Because of the high pressure, winds are weak to nonexistent. The high-pressure system makes it difficult for clouds to penetrate the area, making sunlight harsher and heating the system up even more. All of these elements work in concert to produce the heatwave, a period of very high temperatures.
How deadly a heatwave can be ?
When we heard of deadly calamities earthquake, tsunami, flood, hurricane etc etc hits our mind. Heat wave is not familiar to us when we talk about natural disasters as we see it as a normal increase in temperature during the summer days but it's as deadly as other disasters or even more dangerous. Here are some of the infamous heatwaves back in the history :-
1) London's great stink (1858)
Country :- United Kingdom
Death count:- unknown
2) New York heat wave (1896)
Country:- Eastern North America
Death count :- 1500+
3) Argentina heat waves (1900)
Country:- Argentina
Named as "The weak of fire" first eight days of February
Death count :- 478
4) Eastern United States heat wave
Country:- Eastern America
Death count :- 9500
5) France heat waves (1911)
Country:- France
Death count :- 41,072
6) North American heat wave (1936)
Country:- America
Heat wave followed by the coldest winter
This wave reached to Canada from America
Death count:- unknown
7) South Australian heat wave (1960)
Country:- Australia
Highest temperature recorded in southern hemisphere (123.3°F)
Death count:- unknown
8) United States heat wave (1980)
Death count:-1000+
Temperature reaches 117°F and causes economic loss of $20 billions
9) United States heat wave (1988)
Country:- America
Death count :-17000+ (estimated)
10) European heat wave (2003)
Country:- France, Germany, UK, Portugal, Spain
Death count:- 15000
11) Karachi heat wave
Country:- Pakistan
Death count:- 2500
12) Kuwait heat wave (2016)
Country:- Kuwait
Temperature reaches 129°F, highest ever recorded in eastern hemisphere and on earth (outside death valley)
13) Indian heat wave (2016)
Country:- India
Temperature reaches 123.8°F , 330 million people affected
Heat waves and climate change
Since pre-industrial times, the planet's average temperature has increased by 1.1C, mostly as a result of the massive increase in greenhouse gases caused by human activities. The primary cause of global warming is carbon dioxide (CO2), whose atmospheric content increased by 48% between 1750 and 2020. CO2, methane, nitrous oxide, and other gases trap the sun's heat like glass in a greenhouse, reducing the amount of warmth that escapes into space.
A recent expert research found that the likelihood of a heatwave, which would have had a one in ten chance of occurring in any given year in the pre-industrial environment, has increased by almost three times, with an average increase in temperature of 1.2C. A heatwave will occur five times more frequently than it would have previously, once every 50 times.
In most places, daily high and low temperatures will rise by at least 5 degrees Fahrenheit by the middle of the century and by 10 degrees Fahrenheit by the end if greenhouse gas emissions are not drastically reduced. By the middle of the century, most locations are expected to have 20 to 30 additional days that are 90 degrees Fahrenheit or above. When heat waves are accompanied by high humidity, they become more hazardous. The heat index calculates the temperature and humidity combined. According to a recent study, compared to the end of the 20th century, the yearly number of days with a heat index above 100 degrees F would double, and days with a heat index exceeding 105 degrees F will treble.
Threats due to heat waves
Extreme heat can make other forms of calamities more likely. Drought can be made worse by heat, and wildfires can be sparked by hot, dry weather. The urban heat island effect is a phenomenon where temperatures in urban centers can be 1 to 7 degrees F hotter than in outlying areas as a result of buildings, roads, and infrastructure absorbing heat. The impact is greatest during the day, although cities can remain significantly hotter than the surrounding areas overnight due to the infrastructure's delayed release of heat or an atmospheric heat island. People, ecosystems, and the economy are all at risk as a result of the nation's rising temperatures.
Heat waves : Threat to human health
Over 600 individuals each year on average died from 1999 to 2009 from weather-related reasons other than hurricanes, making extreme heat one of the most common causes of weather-related mortality in the US. Heat waves are included as six of the top 10 deadliest U.S. catastrophes since 1980 in the National Oceanic and Atmospheric Administration's Billion Dollar Weather Disasters database.
Humans experience heat stress when their bodies are unable to adequately cool down. Sweating is normally a way for the body to cool itself, but in conditions of high humidity, perspiration won't evaporate as rapidly, which could result in heat stroke. High evening temperatures and high humidity are probably the main factors causing heat-related sickness and fatalities. Without a break from the heat at night, people may experience pain and health issues, especially those without access to cooling, who are frequently those with poor means. Older persons, newborns, kids, those with ongoing medical issues, and outdoor laborers are additional populations who are particularly susceptible to heat stress. Increases in heat-related ailments, such as cardiovascular and respiratory diseases and kidney diseases are also linked to hot days.
Extreme temperatures also have an impact on the quality of the air. Days with high temperatures and plenty of sunshine can increase the production of ground-level ozone, a dangerous pollutant that is the main ingredient in smog and can harm the respiratory system. Asthmatics are especially vulnerable to this pollutant's effects. Additionally, increased air conditioning use uses more electricity, which, depending on the electricity source, releases various pollutants including particles that also affect the quality of the air. The same vulnerable groups that are already directly harmed by heat are particularly at danger from these increases in ozone and particle matter.
~aMoM
Comments
Post a Comment