CLIMATE CHANGE AND CARBON FOOTPRINT

        Introduction

This topic is closely related to Environmental Engineering. Global warming is becoming a huge problem all over the  world including Sri Lanka. Global temperature rise, warming oceans, shrinking ice sheets, glacial retreat, decreased snow cover, sea level rise, declining arctic sea ice, extreme events, ocean acidification are the some of the evidence of the global warming. The rising temperature can be felt and it keeps rising compared to past. It’s becoming intolerable.  The world's average surface temperature has risen by about 0.98 degrees Celsius compared to late 19th century(Climate Change: Vital Signs of the Planet, 2020). 

Figure 1:  World's average surface temperature by years (Climate Change: Vital Signs of the Planet, 2020)

Sea level has risen by 96 (± 4) mm compared to late 19^th century, at the moment rate of rising is 3.3 mm per year and every year it’s  keep accelerating (Climate Change: Vital Signs of the Planet, 2020).

 

Figure 2: Sea level by years (Climate Change: Vital Signs of the Planet, 2020)

Greenhouse gas emission is the main reason behind global warming. Water vapour, carbon dioxide, methane, nitrous oxide and ozone are the primary greenhouse gases. Carbon dioxide (CO₂) is one of the most important and abundant greenhouse gases in the atmosphere. On the other hand, CO2 is necessary for the composition of the environment, but having excess amount of CO₂ is problematic. The excess CO₂ is generated by human activities such as factory exhausts, vehicle exhaust, burning materials and industrial revolution and globalization are also to be blamed for the increase of CO₂ in the atmosphere; CO₂ level in 1750 was 280 ppm, it has increased by nearly 47% and now in 2020 it has risen to 412 ppm (Climate Change: Vital Signs of the Planet, 2020). It was estimated that fossil CO₂ emissions were 18,454,691 tons in 2016 and it was stated that CO₂ emissions per capita 0.88 tons per person in 2016, an 8% increase over the previous year record (Sri Lanka CO₂ Emissions - Worldometer, 2020).

Figure 3: Carbon dioxide level by years (Climate Change: Vital Signs of the Planet, 2020)

Figure 4: Sri Lanka fossil CO2 emission by sector (Sri Lanka CO2 Emissions - Worldometer, 2020)

In the city of Kandy, the polluted air has already become an issue due to vehicle exhaust being trapped in between the mountains. This has caused diseases, rise in temperature and is harmful to plants. It’s better to take action now to reduce CO₂ emissions before it causes irreversible damage in the future (Population exposure risk assessment to air pollution in Kandy city area, 2012). Cities like Colombo are also at high risk due to population and rapid rise in personal vehicles; the polluted air has been trapped in between high-rise buildings. Hence air quality drops down and also temperature rises due to heat island effect.

Heat Island Effect

When vegetation is replaced by asphalt roads, concrete buildings and other structures to facilitate the growing populations, heat island effect occurs. These structures absorb solar radiation, causing surface temperature and overall ambient temperatures to rise. Removal of vegetation reduces the evaporation and shading, while evaporation and shading are cooling the environment naturally. High rise buildings and other modern structures trap  hot air in between them and reduce the air flow. Vehicles, air conditioners and factories further increase the heat island effect. Even at night temperature will be high due to the emission of heat that is absorbed in day time. Hence heat island effect can occur throughout the year, day and night.

Figure 5: Illustration of Heat island effect (What Is the Heat Island Effect? - Green Ribbon, 2020)

                                

Current solutions practiced in Sri Lanka

• In Sri Lanka, 82.4 % of electricity is produced using fossil fuel and only 17.6% produced from renewable energy sources like hydro power plant and wind mills (CEB, 2020). Therefore, the government focusesing on renewable energy capacity development (ceylonCeylon electricity board, long term generation expansion plan 2018-2037, 2018).

Figure 6: Renewable energy capacity development

• Solar development program of the government, Ceylon Electricity Board is promoting such as Development of Rooftop Solar PV Installations and Development of 60 x 1MW Solar PV Projects (ceylonCeylon electricity board, long term generation expansion plan 2018-2037, 2018).

• Building and developing the wind mills in mountain and coastal areas to generate electricity such as Development Mannar Wind Farm Project.

• Central Environmental Authority has enforced a new tax system in 2007 for the CFLs and LED bulbs, which are energy efficient. This encourages the customers as well as the industry people to produce and supply more CFL and LED bulbs. It reduces the demand and wastage of electricity (climate Climate change mitigation – sri lanka’s perspective, 2012).

• Burning solid waste is also a cause of excess CO₂ so Waste Management Authority is working on safe disposal of waste while the National Council for Sustainable Development is improving recycling and safe removal of solid waste in every local authority (Climate change mitigation – sri lanka’s perspective, 2012).

• Government promoting agriculture, home gardening and urban agriculture, which can reduce CO₂  emissions.( Climate change mitigation – sri lanka’s perspective, 2012)

• Gasoline vehicles are one of the major CO₂ emitting sources; therefore, the government is promoting electric cars by reducing import taxes on electric cars. Further, to reduce the number of private vehicles government is trying to improve public transport (Climate change mitigation – sri lanka’s perspective, 2012).

Conclusion

Three things should be pure and harmless in the world; the food we eat, the water we drink and the air we breathe. Hence, we are in a critical stage; we are responsible for the surrounding environment and we have to ensure a better future for the coming generations. It’s essential to find a solution for this issue. One person alone can’t change the situation, thus we have to think and act as a community. By taking simple steps we can reduce the carbon footprint such as avoiding private transport and using public transport more, using renewable energy sources like solar energy, hydro power and wind power, reforestation and etc.

Sritharan Seran

Department of Civil Engineering,

University of Sri Jayewardenepura.

References

Ranasinghe, D. (2012). CLIMATE CHANGE MITIGATION – SRI LANKA’S PERSPECTIVE. Proceedings of International Forestry and Environment Symposium, 15(0), pp.290-296.

Climate Change: Vital Signs of the Planet. (2019). Climate Change: Vital Signs of the Planet. [online] Available at: https://climate.nasa.gov [Accessed 28 Apr. 2019].Green Ribbon. 2020. What Is The Heat Island Effect? - Green Ribbon. [online] Available at: <http://www.gardinergreenribbon.com/heat-island-effect/> [Accessed 12 April 2020].

Worldometers.info. 2020. Sri Lanka CO2 Emissions - Worldometer. [online] Available at: <https://www.worldometers.info/co2-emissions/sri-lanka-co2-emissions/> [Accessed 13 April 2020].

 2012. Population Exposure Risk Assessment To Air Pollution In Kandy City Area. Colombo: NBRO, p.6.

 Climate Change: Vital Signs of the Planet. 2020. Climate Change: Vital Signs Of The Planet. [online] Available at: <https://climate.nasa.gov/> [Accessed 10 April 2020].

018. CEYLON ELECTRICITY BOARD, LONG TERM GENERATION EXPANSION PLAN 2018-2037. CEB, pp.page 5-1 to 5-20.

Ceb.lk. 2020. CEB. [online] Available at: <https://www.ceb.lk/electricity-generated/en> [Accessed 13 April 2020]