An Introduction to Climate Change

Climate change poses one of the most principal threats to the biological diversity of the planet and is projected to become an increasingly important driver of change in the coming decades [1].

In simpler terms, climate refers to the weather conditions - such as temperature, humidity, and rain - present in an area over a long period of time. On the other hand, biodiversity is the variety of plant and animal life that can be found in a particular habitat, or in the world generally. 

The recurrent shifts in the earth's orbit trigger changes in climate. Simultaneously, the climate is affected by human activities, such as deforestation, and the burning of fossil fuels. Overall, climate change is a combination of both human activity and natural factors. 

As more heat is being absorbed and trapped in the earth’s atmosphere, there is an increase in the greenhouse effect, causing global warming which is a threat that has posed negative consequences to the earth.

In 1896, the Nobel Laureate Svante Arrhenius predicted that the increasing level of carbon dioxide in the atmosphere from burning fossil fuels would lead to global warming [1]. The earth has provided us with optimal conditions for life, and the ozone layer has protected us from the sun’s harmful UV rays, and how are we returning the favour? We emit greenhouse gases and use aerosols, which deplete our environment.

The term ‘greenhouse gas’ encompasses many substances: water, methane, carbon dioxide, nitrous oxide, chlorofluorocarbon and many more. They help insulate the earth by preventing the escape of heat from the sun. The gases absorb solar energy and keep the heat close to the earth rather than letting it escape into space. The trapping of this heat is known as the "greenhouse effect". Currently, these gases are out of balance due to human activities, such as fossil fuel burning, which releases carbon dioxide, and driving, which results in car exhausts releasing nitrous oxide, methane and carbon dioxide. 

Climate change has affected the ocean drastically, raising its temperature, causing it to lose oxygen frequently. The biodiversity of the ocean has also been significantly impacted due to overfishing and coral bleaching, resulting in the depletion of the coral reef, one of the most important biodiversity hotspots.

The coral reef serves as a resource for absorbing elements and reducing wave energy, which contributes to environmental protection and the formation of other ecosystems. Moreover, it is advantageous for generating food resources, boosting the tourism industry, and for medical purposes. It also provides essential nutrients for the marine food chain and is a source of nitrogen, which helps with the fixation of carbon and nitrogen.

The shifting weather patterns could threaten food production drastically; if climate change progresses, livestock may not be able to live in such unstable temperatures and additionally, more crops would be damaged.  Furthermore, there is likely to be a high rate of food insecurity as the resource demands of the population increases, leading to a rise in the cost of food and a reduction in food production. 

Consumers and manufacturers have been following a linear model of consumption where materials and products are manufactured/purchased, used, and then discarded as waste. Whereas, we should be positioning ourselves for the circular economy practice (Fig. 1) which is a continuous cycle where consumers and manufacturers follow the process of manufacturing/purchasing, using, recycling and back to the starting phase. Let’s embrace sustainability and biodiversity and stop the linear flow and transition into the circular flow of the economy.

Figure 1: Structure of the linear and circular economy. Reprinted from Ref [3].

Overall, the severe impact of climate change and consequent biodiversity loss must be taken seriously if we are to sustain our way of life. We cannot keep following the same routines, that caused this crisis in the first place. We must change [2].

References

[1] S.K. Palita, “GHGs and Climate Change”, in Climate Change and its Impact on Biodiversity, 2016, pp.28.

[2] Ahmed Djoghlaf, (2007). “Biodiversity and Climate Change”, Convention on Biological Diversity. [Online]. Available: https://www.cbd.int/doc/bioday/2007/ibd-2007-booklet-01-en.pdf 

[3] Anon. ‘Circular Economy’, Towards Zero Waste. [Online]. Available: https://www.towardszerowaste.gov.sg/circular-economy/