Indian cities are not just increasing in population and density, but are also experiencing increased temperatures and worse air quality due to increasing urbanisation and the proliferation of heat-retaining surfaces such as concrete. Many blame traffic for pollution; however, few people take into account the many everyday materials, such as plastic packaging, that contribute to both urban heat and pollution.

Most people do not think about the environmental impact of plastic when they use it, yet plastic packaging has a much larger environmental impact than most realise. Compostable bags also impact the environment by providing an alternative to plastic bags in urban areas; however, there are few studies available that discuss compostable bags’ impact on urban climates.

In addition to plastic being a key factor in how hot cities are and how polluted they are, plastic also indirectly contributes to both problems by blocking drainage systems, increasing landfill fires, and causing microplastic contamination. Therefore, the role of compostable bags in urban pollution and heat is vast, and their impact is expedited by compostable bags being primarily thought of as a waste management product

The Urban Heat Problem in Indian Cities

Urban heat islands are defined as urban areas that have significantly higher temperatures than their surrounding rural areas. India is seeing an increasing urban heat island effect due to the rapid urbanisation, loss of trees and green space, and increased use of heat-absorbing surfaces such as concrete and asphalt.

The accumulation of plastic waste adds to the urban heat island effect in subtle but substantial ways. Plastic bags and  plastic packaging are consistently accumulating on roadsides, the tops of buildings, in storm drains, and in landfills, and the presence of these materials will ultimately diminish the effects of increasing green space removal due to increasing urbanisation.

How Plastic Bags Contribute to Urban Heat

Plastic, being made from petroleum, does not maintain heat well. As plastic bags accumulate in the urban environment, they retain heat rather than allow it to dissipate.

Some of the ways that plastic shopping bags contribute to urban heat include:

• Galloping solar radiation, thereby absorbing & trapping it
• Covering soil areas, capturing moisture and blocking it from evaporation;
• Raising the temperature of landfills; and
• Creating fires at landfills during periods of extreme heat.

Although each effect might be small when considered separately, when combined with the millions of plastic shopping bags that have been discarded annually, collectively they can have a huge impact on localized temperature trends.

Compostable Bags and Heat Reduction

Compostable bags are produced using plant based resources such as cornstarch, cellulose or other organic polymers. As opposed to oils and fossil fuels that do not return their nutrients back to the earth and create bags out of petroleum based resins that accumulate heat over time, these biodegradable products provide other options for returning nutrients to the earth.

Because compostable bags will decompose into a natural product over time, they do not add to the urban heat build-up in cities like plastic does. This simple change alone helps decrease the difficulties associated with urban heat created by the excess accumulation of plastic bags and other certain types of plastic products.

Reducing Landfill Heat and Fire Risks

Landfills are the largest sources of heat pollution in urban areas, especially in India where most landfills are either uncontrolled or overfilled; and as a result, the presence of too much plastic material in landfills (and the resultant accumulation of plastic) creates extreme heat for an extended period, resulting in an increased risk of fire in our urban environments.

Compostable bags change landfill behaviour in important ways:

• They decompose instead of persisting for decades
• They reduce plastic concentration in waste piles
• They lower long-term surface temperatures
• They reduce fire risk during the summer months

Landfill fires create large amounts of toxic smoke and greenhouse gases which adversely affect the quality of air in urban areas. Compostable bags can mitigate the effects of landfill fires by decreasing the amount of combustibles produced in these fires.

Improving Air Quality Through Better Waste Decomposition

Air pollution in cities is not limited to the emissions produced by vehicles. When waste breaks down in a plastic-laden environment, it provides an ample amount of opportunity for the pollution produced by the anaerobic process to release the gases: Methane, Ammonia and VOC’s.

Plastic bags keep organic waste in a sealed environment. This type of sealed bag prevents oxygen from being able to reach the waste and as a result, organic waste will decompose anaerobically. With this type of decomposition occur foul smells and increased levels of gases being emitted into the air, thus resulting in a detrimental effect to the overall quality of Urban Air.

Compostable bags allow organic waste to break down naturally and give an added benefit by permitting the decomposition process to be controlled. The increased airflow within a compost pile allows the organism’s rate of digestion and thus decreases the amount of harmful pollutants into the Urban Atmosphere.

Cleaner waste breakdown directly contributes to healthier urban atmospheres.

Preventing Microplastic Pollution in Cities

Urban areas are now impacted by microplastics pollution. This invisible form of plastic pollution is found within the air, soil and drinking water of our cities. The use of plastic bags has been identified as a major contributor to this type of pollution.

Under the effects of the sun and Heat, plastic bags will break down into smaller pieces of plastic. These very small pieces will stay suspended within the environment for some time and they will absorb heat and also negatively impact air quality.

Compostable bags will not create microplastics. When compostable bags break down, they will revert back into organic matter and will not leave behind a long-lasting pollutant in the environment.

The ability to prevent the generation of microplastics and the return of compostable bags back as a source of organic matter, are some of the reasons why compostable bags are critical in reducing long-term pollution in urban areas.

Supporting Urban Green Spaces

Governance is directly supported by trees, parks and soil. Urban areas are filled with heat from the sun. A way to mitigate the effects of this heat is by changing the way we build our cities. Trees, parks and soil act as cooling mechanisms through shade and evaporative cooling (evapotranspiration). Waste, plastics and other solid waste materials disrupt the natural cooling of urban areas by blocking or covering the ground.

Like traditional plastic bags, if disposed of correctly compostable bags do not remain in the environment for long periods of time. If a compostable bag does enter into the soil system, it will break down and provide nutrients to the growing plants rather than smother the plants.

Compostable bags allow for soils that are healthier and produce stronger plants, which enables cities to cool themselves without any external (human) efforts.

Reducing Drainage Blockages and Heat Stress

Numerous urban drainage systems become blocked due to plastic bags. Stagnation of rainwater in blocked drain systems creates increased amounts of moisture and creates areas for breeding diseases.

More environmentally friendly compostable bags are less likely than plastic to create drainage blockage because they will eventually break down instead of sitting in landfill sites indefinitely. More efficient drainage systems improve the flow of rainwater through a city’s stormwater drainage system, which will enable cooler surfaces to develop and therefore help mitigate areas of heat stress in a city.

Cities that have efficient stormwater drainage systems generally have lower surface temperatures and better air circulation than cities with inefficient drainage systems.

Lowering Carbon Footprint in Urban Supply Chains

The other major contributor to urban air pollution is the carbon footprint associated with consumer products that are purchased and consumed within cities. Plastic bags are a carbon-based fossil fuel product that emit greenhouse gases into the atmosphere during their manufacturing, transportation and disposal.

Compostable bags (particularly those made from renewable resources) typically produce a lower life-cycle carbon footprint than plastic bags. When more and more businesses in cities move towards utilizing compostable packaging products, the total carbon emissions will be reduced.

The lower total carbon emissions associated with a product type will also assist in preventing additional heat from being trapped in urban environments, which in turns contribute to long-term climate stability.

Health Benefits for Urban Populations

Individuals living in an urban environment can be adversely affected by both urban heat and urban air pollution. Urban heat and urban air pollution are responsible for increased rates of asthma and respiratory diseases, heat-related illnesses, cardiovascular problems, and reduced overall quality of life.

In addition, urban heat, air pollution, and the negative effects of plastic waste are contributing factors to increased areas of urban environmental degradation.

By reducing the number of plastic bags in circulation and into the environment through compostable bags, the creation of a cleaner and cooler urban environment is made possible.

Compostable Bags as Part of Climate-Smart Cities

Using compostable bags helps to create climate-smart cities by creating a sustainable system using nature. Compostable bags coincide with climate-smart urban planning because they are designed to reduce waste, pollution, and heat, and they allow us to add all of these elements to a circular waste system. If compostable bags are widely used in cities, it will encourage the city to establish more sustainable consumption and production patterns. 

Challenges That Need to Be Addressed

while compostable bags are a viable alternative in the fight against climate change, they are also used as a tool for climate adaptation. Ultimately, for cities to benefit from the potential of compostable bags, there must be support for compostable packaging through:

• Clear labelling and certification awareness
• Waste segregation infrastructure
• Composting facilities
• Public education campaigns

By combining policy support to implement compostable bags within these frameworks, cities can impact their environmental outcomes substantially.

The Future of Urban Cooling and Pollution Control

Urban development in India is expected to continue and therefore solutions to address urban heat & pollution will need to be tackled at both an individual level through behavioral and lifestyle changes, as well as through investments in sustainable infrastructure. The use of compostable bags is an easy and effective solution to combating plastic pollution and its effects on our environment.

Compostable bags stop plastic pollution at the source by removing the need to use petroleum-based products to make plastic. They decrease heat retention in the atmosphere and increase the speed at which organic materials will decompose.

Conclusion

As climate change accelerates, cities and the people living in them will be faced with more intense weather patterns. This will increase pressure on urban areas to create more sustainable living conditions. Urban heat will increase dramatically due to the added burden of climate change.

By using compostable products instead of traditional plastic, cities can reduce depleting our planet’s resources, while simultaneously supporting the health of our environment, improving the quality of our air, and enhancing urban life. The use of compostable bags is a simple yet effective way to create cleaner air, cooler streets, and ultimately a more sustainable and healthy urban ecosystem.

FAQs

Q1. Can compostable bags really help reduce urban heat?
Ans-  Yes. By preventing plastic accumulation and reducing heat-retaining waste, compostable bags help lower surface temperatures in urban areas.

Q2. Do compostable bags improve air quality?
Ans-  They support cleaner waste decomposition and prevent microplastic pollution, which contributes to better urban air quality.

Q3. How are compostable bags better than plastic during summers?
Ans-  They reduce landfill fires, lower heat absorption, and break down naturally instead of intensifying heat stress.

Q4. Do compostable bags create pollution when they degrade?
No. Certified compostable bags break down into non-toxic organic matter without releasing microplastics.

Q5. Are compostable bags suitable for Indian cities?
Ans- Yes. They align well with India’s waste management goals and help address urban heat, pollution, and landfill challenges.