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Oceans play a central role in regulating the Earth’s climate. The oceans act as a massive carbon sink which protects us from the worst climate change. Oceans today absorb about one-third of the carbon dioxide humans send into the atmosphere, about 22 million tons a day. Nowadays due to such a rise in pollution levels and rise in greenhouse emissions, the oceans are being adversely affected. These greenhouse emissions cause Global Warming which is a matter of great concern. This global warming affects the whole marine life abominably. CO2 emissions are making the ocean more acidic, making many marine species and ecosystems increasingly vulnerable. The Fifth Assessment Report published by the Intergovernmental Panel on Climate Change (IPCC) in 2013 revealed that the oceans have so far absorbed 93% of the extra energy from the enhanced greenhouse effect, with warming now being observed at depths of 1,000 m. As a consequence, this has led to increased ocean stratification (prevention of water mixing due to different properties of water masses), changes in ocean current regimes, and expansion of depleted oxygen zones in the oceans. Rising sea temperatures are to blame for “coral bleaching”. When the water is too warm ,the corals expel the algae living in their tissues and turn white. As early as 1990, coral reef expert Tom Goreau pointed out that mass coral bleaching events observed during the 1980’s were probably due to anomalously warm temperatures related to climate change. It’s now evident that many coral reefs, including Australia’s Great Barrier Reef, are dying. Mass coral bleaching results in the starvation, shrinkage and death of the corals that support the thousands of species that live on coral reefs. Coral reefs are particularly sensitive to increase in temperature. New researches show that oceans are now experiencing longer and more severe “marine heat waves” that could push even more ocean animals and ecosystems to their limits. Due to these Greenhouse Emissions, the Earth’s atmosphere is getting warmer and warmer each and every day. Atmospheric warming is leading to the melting of inland glaciers and ice, causing rising sea levels with significant impacts on shorelines (coastal erosion, saltwater intrusion, habitat destruction) and coastal human settlement. The warming of the oceans compel the fish to move towards the poles disrupting fisheries around the world. As the atmosphere warms, NASA has observed that sea levels are rising. Water expands as it gets warmer. So, warm water takes up more room in our oceans, and this leads to higher sea levels. Another reason that oceans are rising is due to melting ice on land. Glaciers and ice sheets are large masses of ice that sit on the land. As our planet warms, this ice melts and flows into the oceans. More water in the oceans makes sea level higher. When carbon dioxide (CO2)is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals. These chemical reactions are termed "ocean acidification". Higher acidity is damaging many ocean species that use calcium carbonate to form their skeletons and shells. Studies have shown that calcium carbonate formation is disrupted if water becomes too acidic. Ocean acidification also appears to be affecting whole ecosystems, such as coral reefs, which depend on the formation of calcium carbonate to build reef structure, which in turn provides homes for reef organisms. Ocean acidification can also change the behavior of fish. Recent research has shown that some fish are less able to detect predators in waters that are more acidic. What can we do to protect our oceans? We can perform various steps to protect our oceans: We should reduce our Carbon Footprint by reducing the consumption of meat we should educate people about the adverse effects of climate change over oceans. This way our oceans will be beautiful and fantastic once again.

-By Saksham Gupta (SMSMB)