When animals die, decomposition takes place and their organic matter return to the soil as fossil carbon stores like coal, oil, and gas. These stores are ideal for energy generation since they are highly combustible to release heat energy which is then used to fuel industrial activities. When fossil fuels are burned, carbon dioxide is released, a type of greenhouse gas responsible for trapping heat in the atmosphere. A high concentration of such greenhouse gas will lead to an increase in atmospheric temperature, a phenomenon called global warming. Anthropogenic activates like deforestation and burning of fossil fuel has resulted in 47% of carbon dioxide concentration increase since the industrial age.
Deforestation
The forest is an extremely productive ecosystem, responsible for sequestrating a net 7.6 billion metric tonnes of the atmosphere’s carbon dioxide each year. Through photosynthesis, carbon dioxide is removed from the atmosphere and stored in the plants as biomass, lowering the atmospheric CO2 and preventing them from trapping heat inside the atmosphere.
Between 1950 to 2010, populations tripled from 2.9 billion to 6.9 billion. As standard of living improves with better healthcare and advancement of technology, human’s life expectancy is expected to increase while infant mortality rate decreases. This translates to unprecedented population growth which led to an increase in resource consumption and to keep up with the growing demand, humans are turning to deforestation to free up space for housing, agriculture, and resource acquisition.
Every year, there is a net loss of 0.49% of tropical forest cover which is equivalent to the land area of 100 Singapore (76000km2) meaning that there are lesser trees available for carbon sequestration. Additionally, the methods used to clear these forests also exacerbate the situation. Slash-and-burn is widely practiced in South East Asia and though useful, unregulated clearing is extremely detrimental to the environment. In the process of burning, CO2 is released from the trees and soil and the smog produced also absorbs radiation, amplifying the climate change.
The tipping point
Due to anthropogenic activities, we are pushing our home to the limit, as population grows, our carbon emission follows along too (Fig 1). The correlation between the CO2 level and human population growth is undeniable and based on the current trajectory, we will exceed the planetary threshold and drive earth past the tipping point (Fig 2). Once earth is past the tipping point, our ecosystems may collapse, and the equator may no longer be habitable if the atmospheric temperature increases too much for the human body to evolve in time.
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Header credit: Photo by Matt Howard on Unsplash