The oceans are an expansive natural system interwoven by life forms from all corners of our world. Human activity - specifically increased greenhouse gas emissions - has altered them in ways which are hard to predict or comprehend.
Scientists study the physical and chemical characteristics of Earth's oceans closely, to gain an insight into why temperatures are rising globally and how such changes impact climate.
The Ocean’s role in climate change
The ocean plays an essential role in Earth's climate system. By working closely with its atmosphere to efficiently transfer heat and moisture around the world - for example the Gulf Stream brings warm waters directly from Africa to Europe - the sea is vitally important to global climate regulation. Yet despite these processes' importance we are now experiencing climate change's negative consequences in ocean ecosystems.
Rapidly rising greenhouse gas emissions are rapidly warming the ocean at rates unprecedented in its history, altering species distribution, shifting ecosystem dynamics and diminishing ecological goods and services available for purchase. Marine heatwaves pose an additional threat to coastal habitats and cause shifts in productivity that alter ocean productivity rates.
Oceans are our planet's greatest heat sink and play an essential role in mitigating some of the excess carbon dioxide humans emit into the atmosphere by absorbing it. Unfortunately, their ability to absorb heat has its limits - which we are now beginning to reach.
As the ocean absorbs additional heat, its temperature rises significantly, contributing to sea level rise and endangering coastal communities worldwide. Furthermore, rising ocean temperatures are making it harder for shell-making species such as oysters and corals to form their hard outer skeletons - posing a significant threat as these species provide food sources to many populations worldwide.
As ocean acidification increases, its ability to store oxygen diminishes, with dire repercussions for coral reef systems, food production, coastline protection and other vital functions in its wake.
One of the best ways to safeguard our ocean and its biodiversity is to reduce global emissions of greenhouse gases. Not only does this protect against climate change, but it's also necessary for its natural beauty and ability to support life on this planet.
A comprehensive approach must be taken at national, state, and local levels with measures taken such as limiting fossil fuel usage; developing renewable energy sources; creating incentives to conserve "Blue Carbon" within mangroves, tidal marshes, and seagrass meadows; etc.
The Ocean’s role in carbon sequestration
As the largest carbon sink on Earth, the Ocean absorbs nearly 90 percent of greenhouse gas emissions globally. This excess heat and energy warms its waters and causes many unintended side-effects such as melting ice caps, ocean acidification, rising sea levels, marine heatwaves and changes to circulation patterns in its waters.
Ocean's nutrient cycling plays a pivotal role in mitigating greenhouse gas levels in the atmosphere by drawing carbon dioxide down towards its surface, where plankton absorb it for absorption by bacteria - this process known as "biotic sequestration" has significantly reduced atmospheric CO2 concentrations over the past 2 to 3 billion years.
Human activities have drastically altered this natural process by altering both its physical and chemical properties. Most egregiously is the introduction of large amounts of iron, phosphorus and nitrogen from agricultural runoff and urbanization into the Ocean; this nutrient infusion disrupts phytoplankton absorption capacity while changing pH balance significantly; all this has significant consequences for our planet climate system and will have negative consequences for humans on land as well as sea.
Reducing greenhouse gas emissions is one of the best ways to fight climate change, but many don't realize that ocean ecosystems also play an integral part. Our ocean is home to trillions of tons of organic and inorganic carbon stored within its depths - including mangroves, coral reefs and seagrass beds that will play an essential role in mitigating its effects.
Scientists are investigating how the ocean can help trap extra carbon dioxide from the air. This strategy, known as "blue carbon," involves fertilizing it with iron, phosphorus or nitrogen to promote phytoplankton growth which absorb carbon dioxide from the air before sinking to the bottom where it can be stored for extended periods. While expensive, this technology avoids leakage concerns while offering an attractive alternative to methods that ship carbon dioxide thousands of miles away from its source.
The Ocean’s role in nutrient cycling
The Ocean covers 71% of Earth's surface. It produces at least 50% of all oxygen produced on our planet and holds most of the world's biodiversity.
The oceans play an essential role in nutrient cycling, supporting global food supplies and climate stability. Their intricate network of nitrogen (N), phosphorus (P), and carbon (C) cycles is linked by complex interactions which influence ocean productivity; their effect being altered by environmental factors like interannual climate variability or global warming.
Ocean currents transport heat and moisture from the tropics to the poles, while returning cooler water toward the Equator, helping regulate global temperatures and prevent any extreme hot or cold spots in the ocean. They also transport oxygen throughout the watershed as well as providing essential supplies of nutrients that support marine life.
Wind and Earth rotation affect ocean currents' paths; however, salinity and temperature along with geographic features determine their overall behavior. One such powerful current that travels along the eastern coast of United States is called Gulf Stream; its width stretches 80 kilometers (50 miles). Furthermore, its depth can exceed one kilometer (3,281 feet).
At certain coastal spots, winds and ocean currents combine to cause upwelling, or when winds push surface water away from shore while deep currents of colder water rise instead. This brings nutrients that feed plankton colonies that make up such an integral part of our marine food chains.
Coastal ecosystems rely heavily on cycle cycles for their health and sustainability, yet climate change is already having an adverse impact. Warming of ocean surfaces and changes to atmospheric CO2 levels lead to decreased physical supply of major nutrients as well as diminished upwelling of nutrients from beneath the ocean floor.
People have relied on the Ocean for millennia for food, transportation and exploration - yet have neglected its potential risks. Whalers in particular targeted several whale species for their blubber (wax made from boiled whale blubber) and ivory teeth (which can become endangered species), and many overfished the Ocean to increase revenue while polluting it with harmful substances.
The Ocean’s role in biodiversity
The Ocean is home to an incredible diversity of marine life. Biodiversity refers to variation among organisms found within an ecosystem and can be measured on two dimensions: structural (such as species count) and functional.
Each species contributes unique services that support ecosystem functioning - from marine worms turning organic material into carbon dioxide for photosynthesising aquatic plants, to sharks controlling prey populations. Many of these services are essential, meaning if one disappears then another cannot replace it; disruption would ensue within ecosystem function as a whole.
Human activities threaten marine biodiversity in several ways: climate change, pollution, overfishing and habitat destruction are just a few examples. Furthermore, storms, sea level rise and invasive species all pose direct threats. Loss of marine biodiversity has direct repercussions for those dependent on coastal ecosystems for food and economic income sources.
As Earth's primary carbon sink, the ocean absorbs much of the excess heat and energy created by rising greenhouse gas emissions, resulting in ocean warming which causes further impact such as ice melting, sea-level rise, deoxygenation and deoxygenation. Furthermore, due to rising carbon dioxide levels in the atmosphere, ocean acidity increases, altering conditions for corals and other organisms that build their skeletons from calcium carbonate skeletons and potentially altering coral ecosystems that depend on this form of calcium carbonate for their existence.
Underwater biodiversity is increasingly threatened by human activities like tourism, fishing, shipping, and coastal development. Marine Protected Areas (MPAs) can play an essential role in safeguarding ocean biodiversity from human threats such as tourism, fishing, shipping and coastal development by limiting marine activity to support healthy ecosystems while mitigating climate change impacts.
Health, resilience and biodiversity of the Ocean are central elements in global efforts to combat climate change and achieve sustainable development. To preserve its diversity and services provided, nations must take measures such as reducing carbon dioxide emissions, restoring ecosystem functions, reducing marine plastic pollution, stopping illegal unreported and unregulated fishing activities as well as developing renewable marine energy solutions.
.jpg)
No comments:
Post a Comment