Ocean acidification, resulting from the absorption of carbon dioxide by the seas, poses a critical environmental threat. With 30-40% of human-induced CO2 absorbed by oceans, this phenomenon reduces pH levels, impacting marine life and ecosystems. Despite a seemingly small pH decrease, its logarithmic nature significantly influences chemical reactions vital for life. While oceans initially mitigated climate change by absorbing CO2, recent findings suggest a decline in their capacity, intensifying global warming. Addressing this issue requires global efforts, including emission reduction, sustainable fisheries management, and heightened public awareness.
Acidification of the Oceans
The "other CO2 problem" and the "evil twin of global warming" have been used to ocean acidification.
The continuous lowering of the pH of the seas due to the absorption of carbon dioxide (CO2) from the atmosphere is known as ocean acidification.
Seas, rivers, and lakes absorb between 30 and 40 percent of the carbon dioxide that is released into the atmosphere as a result of human activities.
Some of it combines with the water to generate carbonic acid (H2CO3) in order to reach chemical equilibrium.
Ocean acidity (H+ ion concentration) rises when some of these excess carbonic acid molecules combine with a water molecule to produce bicarbonate and hydronium ions.
When CO2 and water molecules (H2O) combine, the weak acid H2CO3 (carbonic acid) is created. The majority of this acid splits into bicarbonate (HCO3-) and hydrogen (H+) ions. The rise in H+ ions causes the oceans to acidify, or become less alkaline and more acidic, by lowering pH, a measure of acidity. We refer to this phenomenon as ocean acidification.
The only ways to lessen ocean acidification are to monitor CO and CO2 emissions and manage pollution.
Large plankton blooms caused by eutrophication result in a drop in pH and an increase in CO2 as the blooms collapse and sink to the sea floor. This is caused by bacteria respiring the disintegrating algae.
Acid Deposition Types
A combination of wet and dry deposition (a type of deposition material) from the sky is referred to as "acid rain" in general.
Moist Deposition
Acid compounds in the air can fall to the ground as rain, snow, fog, or mist if they are blown into locations with wet weather.
This acidic water impacts a wide range of plants and animals as it percolates through and across the earth.
Deposition of Dry Materials
Dry weather can cause the acid compounds to combine with smoke or dust, which can then descend to the ground through dry deposition and adhere to objects such as cars, buildings, flora, and the ground.
Rainstorms have the power to remove dry deposited gasses and particles off these surfaces through runoff. The resulting combination becomes increasingly acidic due to the runoff water.
Through dry deposition, around half of the atmosphere's acidity returns to Earth.
Acid Rain's Chemical Composition
The creation of acid rain involves six fundamental steps:
Oxides of nitrogen and sulfur are released into the atmosphere by both natural and man-made processes.
A portion of these oxides return to the earth as dry deposition, either nearby or a considerable distance away from their original source.
The creation of photo-oxidants, like ozone, in the atmosphere is accelerated by sunlight.
These photo-oxidants react with nitrogen and sulfur oxides as well as other gases (such as NH3) to oxidize HNO3 (nitric acid) and H2SO4 (sulphuric acid).
Sulfate, nitrate, ammonium, and hydrogen ion-containing acid rain descends as moist deposition
What modifications have been made to the ocean's pH?
Low pH values are regarded as acidic, and high pH values are regarded as basic, on a range that spans from 0 to 14. Neutral is seven. Since the industrial revolution, the pH of the ocean has decreased from 8.2 to 8.1, and by the end of the century, it is predicted to drop another 0.3 to 0.4 pH units.
However, the pH has only slightly changed. Is this truly concerning?
Although a pH reduction of 0.1 might not seem like much, the pH scale is logarithmic, much like the Richter scale used to measure earthquakes. For instance, pH 4 is 100 times (10 times 10) more acidic than pH 6 and ten times more acidic than pH 5. SmallpH variations can affect a lot of chemical reactions, including ones that are vital to life. For instance, the normal pH range of human blood is 7.35 to 7.45. A pH reduction in the blood of 0.2–0.3 can result in comas, convulsions, and even fatalities. Comparably, even a slight variation in the pH of seawater can negatively impact chemical communication, growth, and reproduction in marine organisms.
Alright, but since the oceans absorb CO2, the atmosphere benefits from a decreased rate of global warming. So why should one be concerned?
Many scientists first concentrated on the advantages of this greenhouse gas being removed from the atmosphere by the ocean. Initially, scientists believed that this could be beneficial since it reduces the amount of carbon dioxide in the atmosphere that warms the earth. However, they have discovered in the last ten years that the ocean's chemistry has changed as a result of the warming that has paused.
The possibility that the oceans' ability to retain carbon may decrease as they absorb more CO2 is also concerning. As a result, more of the carbon dioxide we produce will stay in the atmosphere and exacerbate climate change worldwide. Ocean acidification will worsen climate change by lowering the ocean's ability to absorb human CO2.
The effects of acidification of the ocean
Oceans are becoming less friendly to marine life due to plastic pollution, overfishing, global warming, and increased acidification from burning fossil fuels.
The acidity of the ocean will impact corals. One million species that have made corals their home will be impacted by this.
The erosion of coral reefs will outpace their rebuilding. The entire food chain may be in danger when shelled organisms are.
Higher CO2 concentrations may help some algae and seagrass because they may accelerate their growth and photosynthetic rates.
Early in their lives, the majority of marine species appear to be more susceptible.
The effects of pollution, overfishing, coastal expansion, climate change, and agricultural fertilizers will exacerbate the changes brought forth by acidification.
The numerous services the water offers us will be impacted by these changes.
Corals' Response to Ocean Acidification
The oceans are a major source of CO2 and effectively operate as a buffer against climate change, absorbing one-third of the gas created by human activity.
The rate at which atmospheric carbon dioxide is being absorbed is faster than the oceans' inherent ability to act as a buffer.
In certain organisms, higher acidity lowers immunological responses and metabolic rates.
Carbonic acid, bicarbonate, and carbonate ions are created when seawater absorbs carbon dioxide.
However, an increase in atmospheric CO2 levels results in a drop in pH, an increase in bicarbonate ion concentration, and a decrease in carbonate ion concentration.
It is more difficult for marine calcifying animals to create biogenic calcium carbonate, such as coral (calcareous corals) and some plankton (calcareous plankton), due to the decrease in the amount of carbonate ions available.
Because acidification damages the calcifying organisms that are the foundation of the Arctic food webs, commercial fisheries are in danger.
Since corals are extremely sensitive to changes in the composition of the water, increasing acidity accelerates coral bleaching.
Ocean Acidification's Effect on Cloud Formation
The bulk of sulfur in the atmosphere is released from the ocean, frequently as phytoplankton-produced dimethylsulfide (DMS).
A portion of the DMS that phytoplankton produces escapes into the atmosphere, where it combines to form sulphuric acid, which then condenses into tiny airborne particles known as aerosols.
Because clouds reflect sunlight and help cool the planet, aerosols are responsible for their development.
On the other hand, phytoplankton creates fewer DMS in acidified ocean water.
This sulphur reduction could result in less clouds forming, which would raise global temperatures.
Synthetic Cloud seeding
Spreading dry ice or, more frequently, silver iodide aerosols into the top part of clouds in an attempt to initiate precipitation and generate rain is known as cloud seeding.
The purpose of the silver iodide particles is to promote the creation of new ice particles because most rainfall originates from the growth of ice crystals from super-cooled cloud droplets in the upper portions of clouds.
Effects on Society and Economy
Food
Food security may be impacted by ocean acidification.
The yearly expenses to the world of losing mollusks due to ocean acidification could exceed $100 by the year 2100.
safeguarding the coast
There will be an impact on marine ecosystems like coral reefs, which shield shorelines from storm surges and storms' destructive force.
Estuaries and rivers along the coast are being impacted by ocean acidification.
Travel
The effects of ocean acidification on marine habitats could have a significant impact on this business.
Acidification may have negative effects on indigenous peoples' way of life and the Arctic tourism industry.
Humans
unpleasant odors, blurred vision, and irritation of the respiratory system, eyes, and skin.
Cancer, lung emphysema, and chronic bronchitis are a few of the primary impacts.
Impact on Soil
Leaching of nutrients leads to infertility in the soil due to the exchange between hydrogen ions and nutrient cations such as potassium and magnesium in the soil.
The pace of decomposition is slowed down by an increase in ammonia in the soil brought on by a reduction in other nutrients. It is also discovered that the soil's nitrate content drops.
Since the majority of Indian soils are alkaline and have high buffering capabilities, the effects of acid rain on soil are less severe there.
Impacts on aquatic organisms
Fish, frogs, and other aquatic creatures' eggs or sperm are sensitive to pH variations.
Their gametes are killed by acid rain, which disrupts life cycles and productivity (ecosystem imbalances).
Lake waters with high acidity have the potential to kill and degrade bacteria.
Metals that are linked to soils may be discharged into aquatic environments due to acid rain.
Impact on life on Earth
Acid rain weakens plant leaves' cuticles and decreases photosynthesis.
Lead, mercury, and aluminum can all leach more readily from an acidic media. These metals have an impact on soil microflora and fauna when they seep into groundwater.
The loss or modification of food and habitat resources is one of the indirect effects of acid rain on wildlife.
consequences for microrganisms
Proliferation of any microbial species is dependent on pH.
Most bacteria and protozoa have an ideal pH of almost neutral.
The majority of fungus favor an acidic atmosphere.
An alkaline environment is preferred by most blue-green microorganisms.
Thus, microbial species in water and soil transition from being bound by bacteria to being bound by fungi.
The organic matter in the soil takes longer to decompose as a result.
impact on materials, structures, and monuments
Acid rain negatively impacts a lot of old, historical, and antique structures as well as artwork, textiles, and other items.
Acid rain damages marble and limestone. Such objects are coated in soot and smoke. The acid vapors in the air lead them to gradually dissolve or flake away from the surfaces.
Acid rain has caused damage to numerous structures and monuments, including the Taj Mahal in Agra (Marble Cancer).
Areas Hit by Acid Rain
They are centered in the northern hemisphere's industrialized belt.
Northwestern Europe, Canada, Scandinavia, and the Northeast United States.
In the Indian
Bombay was the first place in India to report experiencing acid rain in 1974.
There have been reports of acid rain from large cities.
There have been reports of lowered soil pH from regions of Orissa, West Bengal, Bihar, and coastal Karnataka and Kerala in northeastern India.
Controlling Acid Rain
Acid rain can be prevented in thermal plants by using low-sulfur fuel, natural gas, or washed coal, which is coal that has been chemically cleaned of pulverized coal.
Buffering is the process of raising the pH of acidified water by mixing in a neutralizing substance. Lime is typically used as calcium carbonate and calcium oxide.
Regulation of climate and storage of carbon
As ocean acidification rises, the ocean's ability to absorb CO2 falls.
Oceans with higher acidity levels have less ability to slow down global warming.
Ocean Acidification in the Indian Ocean
The surface waters of the Arabian Sea are becoming more acidic due to an overabundance of carbon dioxide in the atmosphere.
The primary cause of the ocean acidification in the northern Bay of Bengal is the intermingling of pollutants from the Indo-Gangetic plains with saltwater.
All contaminants are carried by the wind and deposit themselves in the water as it travels from the land to the sea during the winter.
Research indicates that marine phytoplankton is becoming less and less common in the western Indian Ocean.
According to a report, given the rates of ocean warming, the Indian Ocean might eventually become an ecological desert.
The Indian Ocean, one of the purest and most fruitful environments on Earth, will be destroyed by ocean acidification in the Arabian Sea and Bay of Bengal.
The Way Ahead
The best way to combat ocean acidification is to reduce greenhouse gas emissions globally, a process known as mitigation.
Enhancements to the quality of water: keeping an eye on and controlling localized sources of acidity caused by contaminants like fertilizers and runoff.
Creation of sustainable methods for managing fisheries: controlling captures to lessen overfishing
Increasing coastal protection, lowering sediment loading, and implementing marine spatial planning are all components of sustainable habitat management.
extensive study on climate engineering to determine the viability and effects of its methods.
Inform or make the general public aware of the dangers that climate change and ocean acidification pose.
lowering the use of energy sources high in carbon.
In conclusion
The menace of ocean acidification demands urgent global action. Despite the oceans' historical role in tempering climate change, the escalating impact on marine life, ecosystems, and even climate regulation processes is alarming. Mitigating this threat requires concerted efforts, from reducing carbon emissions to sustainable fisheries management and comprehensive climate engineering research. Preserving the oceans' delicate balance necessitates public awareness and responsible resource management. The future hinges on mitigating acidification's effects through collective dedication, as neglecting this "evil twin of global warming" jeopardizes not only marine biodiversity but also the stability of our planet's interconnected systems. The path forward must prioritize sustainable practices and informed global stewardship.
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