Only one creature has successfully made a life for itself in every habitat on earth, that is humanity. Since the pre-industrial period, human activities, primarily the burning of fossil fuels, continue to increase the volume of greenhouse gases.
This results in the heating of this planet in a process called Global warming, or as scientists say, the slow heating of the earth’s surface, oceans, and atmosphere, caused particularly by carbon dioxide gas. Yes. Getting higher every day, these gradually warming seas threaten to sink cities in decades while also threatening marine life with increasing extinction rates.
Climatic changes affect the ocean as it likewise affects changes in climate. Oceans directly absorb over 90% of the heat brought about by the ever-increasing concentrations of greenhouse gases in the atmosphere. Fossil fuel combustion is the main source of such gases, carbon dioxide and methane gas being the main culprits. As this heat is absorbed, the temperature of oceans rises, causing the water to expand literally. This is among the main causal factors for the ever-rising sea levels along the coasts of various seas, a process referred to as Thermal Expansion.
According to US NOAA, the average global sea surface temperatures, that is, the upper few meters of oceans, have increased by approximately zero point one three five nine degrees centigrade within the last decade. It doesn’t sound that bad, right? This gradual rise eventually leads to a serious decline in the amount of oxygen gas dissolved in seas, resulting in further thermal expansion in seawater. These rising temperatures, added with ocean acidification due to the high content of dissolved carbon dioxide gas, affect marine ecosystems. Consequently, we lose the fundamental benefits that we derive from oceans. This includes the loss of marine life or the extinction of species that are considered threatened.
The warming of our planet is primarily due to trapped heat brought about by the high accumulation of greenhouse gases. Global ice melt has steadily increased through the past three decades as a result of this. Recent studies show that the rate of ice loss has increased by over 60% just between the years 1994 to 2017. The polar regions, Greenland and Antarctica being the most affected. In fact, according to a study done by the University of Leeds, Greenland’s ice sheet could melt at a rate not seen in over 130,000 years. Though ice loss does not directly result in sea level rise, it still does play a major role. At the current rising ocean rates, cities like Miami, New York, and New Orleans could end up underwater by the next century.
While disappearing beaches and flooding in coastal areas are the most obvious effects of sea-level rise, more impacts may be felt in inland water bodies many miles from any beach. Recent research shows that as seawater levels rise, they create negative pressure at the mouth of underground streams. These originate from the mainland, travel underground through porous rocks, and empty their waters into the oceans. Such may include springs or underground streams formed from Karst features.
When sea levels rise as rapidly as they have been, even a small increase can have devastating effects on drainage features farther inland. It can cause destructive erosion, wetland flooding, aquifer degradation, agricultural soil contamination with salt, habitat loss for fish, birds, and plants. Flooding in some coastal areas is forcing people to migrate to higher ground, leaving millions more vulnerable to flood risk and other climate change effects. Examples of extreme weather conditions experienced on coasts include Hurricanes or Tsunamis.
As sea levels rise, some coastal areas are increasingly being swamped with saltwater, gradually contaminating fertile soil and further inland. These salts can be diluted by adequate rainfall. Climate change is also increasing the frequency and severity of extreme weather events, including droughts or heatwaves. This leads to more intensive use of groundwater, which further depletes the water tables, allowing even more salt to reach fertile soil inland.
Research studies conducted by the Ohio State University show Bangladesh as an example of the most adversely affected regions. Findings show that rising soil salinity is already influencing agricultural production in many other coastal areas where farming occurs from Asia, the US, the Pacific, and the Gulf coasts. Continued atmospheric pollution, majorly through the combustion of fossil fuels, in hand with the destruction of carbon sinks, forests, or vegetation cover, has resulted in further warming of oceans. These temperature rises are the cause for rising water levels in rates never recorded before.