Image created by blog author, Isabelle Lim using Canva

Did you know that temperatures in Singapore are rising twice as fast compared to other regions of the world? Coupled with the high humidity, these rising temperatures could soar to 37 degrees Celsius by 2100. One of the reasons why Singapore is so hot is because we are densely urbanized. Aside from consequences of climate change, urban regions contribute to the temperature rise, through a phenomenon known as the Urban Heat Island (UHI) effect whereby heat produced by human activities are absorbed by urban infrastructure and then released into the environment at night. The rising temperatures increases the risk of heat strokes that could result in death.

Image illustrating urban heat island effect (source)

Green spaces can help us beat the heat by reducing UHI effect! This is done through two processes, shading and evapotranspiration. Leaves and tree branches reduce the amount of sun radiation that reaches the canopy by absorbing energy for photosynthesis Vegetation on buildings act as green cover that deflect heat energy from the sun. Trees help to shade street pavements and parking lots and mitigate the absorption of heat by these infrastructures. The vegetation also release moisture into the environment that provides a cooling effect. This is known as evapotranspiration whereby water taken up through the roots of the tree is released through the stomata on the leaves. When comparing between urban estates with tress to that of those without trees, the vegetation has been proven to cool the area by 2 to 3 degree Celsius.

How trees help us stay cool! (source)

The quality of air in Singapore isn’t as good as we think it is. Across cities globally, Singapore has one of the highest levels of PM2.5 which refers to tiny particles that has a diameter of less than 2.5 micrometers. These particles are emitted into the air as a result of various human activities such as motor vehicles, power plants and agricultural burning. These compounds are smaller and lighter than many other substance and remain in our atmosphere for a longer period of time, increasing our chances of inhaling these substances. Due to the tiny nature of these particles, they can remain lodged in our respiratory system and cause inflammation in the lungs, leading to asthma and bronchitis. Trees are a viable solution to reduce air pollution in our country because they help purify our air through the removal of pollutants and toxins. Leaves take in gases from the environment. Pollutants in the atmosphere then react with the water inside the plants to form acids. Other particles may stick to the surface of plants and get washed of by rain, returning to the soil. These various mechanisms greatly reduce air pollutants in urban regions.

Different types of particles that can be found in our atmosphere (source)

Did you know that one large tree can supply 4 people with enough oxygen for the entire day? Air pollution aside, trees help to remove carbon dioxide and replenishes us with fresh oxygen through photosynthesis. This is important because global atmospheric levels are rising steadily and it is currently higher than they have been for the past 400,000 years! In 2013, CO₂ levels surpasses 400ppm, the first time ever in history. This increase in carbon dioxide can be attributed to the following factors, most of which are human activities:

• Energy production: Burning of fossil fuels, coal and oil generates electricity which is a vital source of energy that powers society. Coal burning plants account for almost half (51%) of the total CO₂ emissions in the United states!
• Transportation: Locomotion is the second largest source of CO₂ This is due to the use of fossil fuels to power our vehicles, such as the car, trains and busses which make up our daily commute.
• Agriculture: Forests have to be cleared to make way for plantations to grow crops. The clearing of trees reduces the amount of vegetation to absorb CO
• Industrial sector: Fossil fuels are used to generate the energy needed to support industries such as mining, manufacturing and construction. The industries which contribute to the highest greenhouse gas emissions are paper, food and petroleum industries.

Image created by blog author, Isabelle Lim using Canva

Carbon dioxide is a greenhouse gas because it taps heat in our atmosphere and contributes to global warming. These gases remain can remain in the atmosphere for up to thousands of years and trap large amounts of energy that warms the surface of the earth. Trees which naturally convert CO₂ into oxygen could be a means to help decrease global warming. Not to mention the shade they provide further cools urban areas.