Thanks to Covid19, carbon dioxide emissions have lessened in many countries, but when the world will return to normalcy, industries will function normally and vehicles will return to the roads. In short, the emissions of carbon dioxide and other noxious gases will resume.
In the Earth’s history, five major mass extinctions of species have occurred. The 5th mass extinction (Cretaceous-Tertiary extinction) event occurred when an asteroid hit the earth some 65 million years ago. The asteroid impact wiped out 80% species on the planet including dinosaurs. According to Dr Andrew Glikson, scientist at Australia National University, if the present rate of growth of carbon dioxide emissions is not checked, it will be difficult for many plant and animal species to adapt and ultimately they will go extinct. Carbon dioxide is the gas that balances the shortwave radiations coming out from the sun and the terrestrial longwave radiations emitted back by the Earth. If carbon dioxide rises in the atmosphere, it allows the shortwave radiations to come through but prevents the longwave terrestrial heat to dissipate into space. The surface temperatures on earth soar, sea level rises and oceans become acidic due to the increasing level of carbon dioxide in water. Scientists estimate that carbon dioxide contributes 60% of the global warming among all the greenhouse gases.
Prior to the industrial age, slightly less than 300 parts per million (ppm) of carbon dioxide was present in Earth’s atmosphere (troposphere). In February 2020, atmospheric carbon dioxide was 414.1 ppm and total greenhouse gas level was 500 ppm. This suggests that industries are to blame for carbon dioxide rise in the atmosphere. However, it is not just industries; the loss of trees and plants is as much responsible.
Trees serve as carbon dioxide sinks. They convert the gas into organic matter with the help of sunlight. Trees are pivotal in maintaining the carbon dioxide level in the atmosphere, but forests are shrinking at staggering rate. In 2018 about 120,000 sq km of tropical forests were lost worldwide. It is estimated that 1.5 billion tonnes of carbon dioxide are added to the atmosphere per year due to deforestation.
The increasing levels of carbon dioxide is also having an effect on the glaciers of the world. The snow on Kilmajaro peak has melted more than 80% since 1919. Himalayan glaciers are retreating at faster rates. It is feared that the central and eastern glaciers of Himalayas will virtually disappear by 2035.
According to a study published in Nature journal, global warming would lead to catastrophic species loss. “It is not a slippery slope, but a series of edges, hitting different areas at different times”, said Alex Pigot, a senior author of the study. However, some scientists claim that the devastation is avoidable if carbon dioxide emission is curbed immediately. The world’s wildlife declined by 60% from 1970 to 2014, according to a Living Planet Report.The day is not far when all the living species will be extinct if carbon dioxide emission is not curbed.