Another Contributing Factor To Global Warming


Ocean Acidification will Endanger Marine And Human Life

Global warming continues to be a matter of great concern. Scientists are now 95 percent certain that humans are the cause of global warming, but the recent findings suggest that the oceans are aggravating the situation as well.

In lay terms, global warming is the rise in the earth’s average temperature, including its atmosphere and oceans. The reason for the sudden change in climate, the melting ice caps and rising sea levels can be attributed to humanity’s continued pursual of modern life.

It is majorly caused by the release of heat-trapping gases into the atmosphere, most of which comes from combustion of fossil fuels in cars, factories and production of electricity. While carbon dioxide (CO2) is the most harmful, other gases include methane released from landfills and agriculture (especially from the digestive system of grazing animals), nitrous oxide from fertilizers, gases used for refrigeration and industrial processes, and last but not the least, deforestation.

These greenhouse gases have collectively formed a thick blanket that traps the heat from the sun and in turn heat the planet. But that’s not all they are also adversely affecting the ocean and its inhabitants. The oceans are absorbing a large portion of CO2 and this absorbed carbon reacts with water to form carbonic acid.

According to a study, carbonic acid lowers the pH balance of the oceans, making them more acidic. It also hampers the production of dimethyl sulfide (DMS), an insoluble sulfur compound produced by plankton.

Sulfur in the form of sulfur dioxide and  DMS is not a greenhouse gas. Furthermore, higher levels of sulfur in the earth’s atmosphere can reduce the amount of solar radiations reaching the surface and thus produce a sulfur cooling effect. Remember the eruption of Mt. Pinatubo in the Philippines in 1991? Millions of tons of sulfur dioxide were produced, which caused the global temperatures to drop by 0.5 degree Celsius temporarily (1991 through 1993).

DMS, which is the largest natural source of atmospheric sulfur, helps in reducing the surface temperatures on earth, by reflecting incoming radiations from the sun. And scientists have suggested that an 18 percent decline in DMS emissions by the year 2100 could cause an increase as much as 0.48 degree celsius (0.9 degree fahrenheit) to the global temperature. This decline in DMS will only add to the already projected rise in global warming, which is said to be somewhere between 1.1 to 6.4 degree celsius, depending on the emission scenario of the world.

In addition to that, ocean acidification may have an unseen effect on marine biology. The imbalanced pH levels of the sea are likely to affect certain categories of marine life such as corals, echinoderms, mollusks (oysters and squids), crustaceans (lobsters and crabs) and even fishes, because they don’t respond well to acidification.

Another research, published in the journal Nature Climate Change, suggests that if global warming continues to rise it will expose 42 percent of the earth’s land, including parts of India, Southeast Asia and Africa, to the risk of flooding. And if temperatures rise by 3.5 degree celsius by the end of this century and there is an increase in the sea levels, the number of people exposed to the risk of flooding would be 80 million as against the current estimate of 5.6 million.

Global warming has far reaching ramifications in the form of increasing sea levels by more than 7 inches, hurricanes, increase in floods and droughts due to climatic changes, extinction of species and many others. But with the oceans also adding to the problem of global warming, it would mean further damage to ecosystem. Thus directly endangering the millions of species it is a habitat to and indirectly accelerating the inevitable doom of human life.

Smriti Sharma

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