Trees: City Pollution Fighters And Air Purifiers

In the game Cities: Skylines, trees are a great way to reduce noise pollution. They can be placed in noise-heavy areas, near roads, or even around industrial and public transport buildings to control noise levels. While trees don't help with ground pollution, they can improve the health of your citizens by reducing noise pollution when used in large numbers. Trees also increase land value and citizen happiness by reducing noise.

Trees reduce noise pollution

Trees are a natural solution to noise pollution, which is defined by the EPA as "unwanted or disturbing sound". In the game Cities: Skylines, trees reduce noise pollution, but only when used in large numbers. Trees act as noise barriers and reduce noise pollution through a phenomenon called sound attenuation, which is the reduction of sound intensity. Sound attenuation occurs when sound waves dissipate over longer distances until there is no energy left to vibrate the air.

Trees can reduce noise levels by 50% as perceived by the human ear. The percentage of noise a tree can block depends on several factors: the intensity, frequency, and direction of the sound, as well as the location, height, width, and density of the tree. A tree barrier with an open distance of 100 feet can reduce sound by 21dB. A dense tree belt of 15-30m wide could reduce noise levels by 6-10 dB.

Trees also mask annoying noises when branches sway, leaves rustle, or stems creak. Additionally, trees and shrubs attract birds and squirrels, whose natural sounds help mask noise pollution. The more surfaces a tree has, the better it is at reducing noise. Therefore, broadleaved trees are more effective at blocking noise than needle-leaf trees.

To create an effective noise barrier, diverse structures should be used to prevent gaps and add varied textures to the environment. This includes trees, shrubs, bushes, vines, and herbaceous plants. The width of the vegetation barrier and its distance from the noise source are also important factors in its effectiveness. A buffer planted closer to the noise source will block more noise than one farther away.

Trees don't help with ground pollution

In the game Cities: Skylines, trees do not help with ground pollution. Ground pollution is mainly caused by industry, fossil-fuel power stations, incinerators, and farming and forestry industry specializations to a lesser extent. Ground pollution will also occur if non-polluting buildings have uncollected garbage for a long time or if there is sewage water present.

Trees do, however, help to reduce noise pollution. They can be planted along roads to reduce the amount of noise pollution the road creates. Trees also have a positive impact on the health of the city's citizens, as noise pollution can cause sickness and even death.

Trees improve population health

Trees are known to reduce noise pollution, which has been linked to negative health outcomes such as stress, unhappiness, sickness, and even death. By lining highways and roads with trees, cities can effectively reduce noise pollution and improve the health and well-being of their residents.

Trees also play a critical role in removing air pollution, which has been associated with various health issues such as bronchitic symptoms, increased risk of glaucoma, heart attacks, cognitive development problems, and even mortality. Urban trees are estimated to remove a significant amount of air pollution each year, making cities healthier places to live.

The presence of trees and green spaces has been shown to improve mental health and reduce stress levels. Research has found that living in areas with more green space leads to lower levels of the stress hormone cortisol and improved mood. Doctors even prescribe fewer anti-depressants in urban areas with trees!

Trees can also improve physical health by encouraging physical activity and providing a nutritious food source. Residents of tree-lined communities have been found to have fewer cardio-metabolic conditions, as trees promote a more active lifestyle and provide access to healthy foods such as fruits and nuts.

In addition, trees have been linked to improved cognitive development and educational outcomes. Children with views of trees are more likely to succeed in school and have improved concentration and attention, which can be especially beneficial for those with conditions such as ADD and ADHD.

Furthermore, trees can aid in the recovery from illness and improve cardiovascular health. Studies have shown that spending time in nature or even just looking at trees can reduce stress, lower blood pressure, and promote relaxation. This, in turn, can lead to improved overall health and well-being.

Lastly, trees have been shown to reduce violent crime and improve the social capital and ecology of communities. Well-maintained trees and green spaces foster a sense of community and belonging, which contributes to the cultural fabric of cities and makes residents feel safer.

Trees don't help with air pollution

While trees are often praised for their ability to reduce air pollution, there is evidence to suggest that they may not be as effective as commonly believed, especially in certain contexts. Here are several reasons why trees may not always help with air pollution:

• Limited Effect on Ground Pollution: In the context of the game Cities: Skylines, trees are reported to have no impact on ground pollution, which is mainly caused by industry, fossil fuel power stations, and incinerators. While trees can reduce noise pollution and have aesthetic value, they do not address the issue of ground pollution.
• Species and Context Matter: Not all tree species are equally effective at reducing air pollution. Conifers, such as pines and cypresses, are often touted as excellent pollution filters, but they may not be suitable for all urban environments due to their sensitivity to salt levels in soils and their potential to block sunlight from melting snow and ice.
• Planning and Placement: The placement of trees is crucial. Poorly planned tree-planting schemes can be ineffective or even counterproductive. For example, tall trees with large canopies may trap pollution in narrow streets surrounded by tall buildings, making the problem worse. Hedges or green walls are often more suitable in such contexts.
• Maintenance and Lifespan: Trees that require minimal maintenance and have longer lifespans are generally preferred for urban settings. High-maintenance trees or those with shorter lifespans may not provide long-term benefits and can be costly to manage.
• Indirect Effects: While trees can reduce air pollution through shading and temperature reduction, leading to decreased energy consumption, this is an indirect effect. Direct removal of pollutants by trees is a more significant factor in improving air quality.
• Emissions Reduction is Key: While trees can help mitigate existing pollution, the best way to improve air quality is to reduce emissions in the first place. This involves addressing the root causes of pollution, such as industrial processes, vehicle emissions, and power generation.

In conclusion, while trees can play a role in reducing air pollution, it is not a straightforward solution. The type of tree, its placement, and the specific context of the urban environment all play a role in determining the effectiveness of trees in combating air pollution. Relying solely on trees without addressing other factors may provide a false sense of improvement while failing to address the root causes of the problem.

Trees don't help with water pollution

In the game Cities: Skylines, trees help to reduce noise pollution but do not have any effect on water or ground pollution. Trees lined along roads can reduce the amount of noise pollution created by the road. However, trees have zero effect on other types of pollution in the game.

In the game, sewage is produced by virtually all buildings and is transported through the same pipes as clean water. If left untreated, this sewage can cause water pollution, making citizens sick and reducing their happiness. While water treatment plants can eliminate 85% of the pollution from sewage, the remaining 15% can still contaminate water sources and impact the health of the population.

To address water pollution in Cities: Skylines, players must focus on proper sewage disposal and treatment. Floating garbage collectors can be placed in bodies of water to filter out pollution. Additionally, water treatment plants can significantly reduce pollution levels in sewage before disposal, minimizing the risk of water contamination.

While trees have a role in reducing noise pollution in Cities: Skylines, they do not contribute to addressing water pollution. Players must rely on other strategies, such as proper sewage management and the use of water treatment facilities, to mitigate water pollution and maintain the health and well-being of their in-game citizens.

Frequently asked questions