However, the main limitations to their use are their hydrophobicity, instability, high volatility, and risk of toxicity.
To these components belong all properties that make essential oils so interesting for pharmaceutical uses the most investigated ones are antioxidant, anti-inflammatory, antimicrobial, wound-healing, and anxiolytic activities. Using a variety of methods refined over the centuries, essential oils are extracted from plant raw materials: the choice of the extraction method is decisive, since it determines the type, quantity, and stereochemical structure of the essential oil molecules. Essential oils are known for millennia and, already in prehistoric times, they were used for medicinal and ritual purposes due to their therapeutic properties. Thankfully, several approaches can help cities keep their cool even amidst a changing climate.Essential oils are being studied for more than 60 years, but a growing interest has emerged in the recent decades due to a desire for a rediscovery of natural remedies. Urban heat islands are one of the most pressing issues facing cities today-and residents are feeling the heat. A model by the MIT Concrete Sustainability Hub estimated that, if widely implemented, cool pavements could reduce the frequency of heatwaves by 41% across all US urban areas. They are made of brighter materials, like concrete and light-colored aggregates, or have been treated with reflective coatings. Cool roofs feature bright coatings that reflect more sunlight and, therefore, absorb less heat. 6Īnother option is to build cool roofs and pavements. One study found that the presence of vegetation can lower nearby air temperatures by as much as around 4 ☏.
#ISLAND THYME DEEP HEAT INSTALL#
Cities can expand parkland, plant street trees, and install “green roofs” designed to harbor plant life. The most obvious way to fight the urban heat island effect is to reintroduce vegetation. To cope with higher temperatures, cars and buildings consume more energy-frequently via fossil fuels-which worsens air pollution and contributes to climate change.
In addition to endangering city-dwellers, heat islands can also harm the environment.
4 These health impacts are often felt inequitably, with low-income and minority communities tending to live in areas more susceptible to heat islands. By heightening air temperatures and intensifying heatwaves, they can cause heat stroke and heat exhaustion as well as other illnesses, like heart attacks. Urban heat islands can pose significant health risks. The geometry of cities also contributes to heat islands: the narrow spaces between tall structures, known as urban canyons, can block wind and trap heat. Though much of that heat comes from the sunlight those surfaces receive, another source of heat is human activities-like power generation and the use of cars and air conditioners. 1 Instead, they tend to absorb and re-emit more heat, which makes their surroundings warmer too. The man-made surfaces that replace these features, however, tend not to have cooling effects. This vegetation, along with soil and water, also helps cool nearby air through “evaporative cooling,” which is a natural process by which evaporating water absorbs heat (much like sweat cools the human body). Trees and other plants, for instance, can lower air temperatures by providing shade. That’s because these natural surfaces help moderate air temperatures. This change in the local environment results in a corresponding change in the local climate. What causes urban heat islands?Īs cities grow, new development such as roads and buildings displace natural surfaces like trees, ponds, and soil. 2 And since nearly 70% of humanity will live in cities by 2050, 3 finding ways to alleviate urban heat islands has become even more pressing. As the planet warms, urban heat islands will only intensify those higher temperatures. People living in urban heat islands are especially vulnerable to the effects of climate change. 1 Scientists refer to areas afflicted by these higher temperatures as urban heat islands. 1 This difference continues well into the night, during which cities can still be as much as 5☏ warmer than the areas around them. On average, cities tend to be 1-7☏ warmer during the daytime. The urban heat island effect is a phenomenon whereby cities experience higher air temperatures than the surrounding countryside.
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