Carbon Dioxide (CO2) is the leading greenhouse gas and accounts for 76% of total greenhouse gases. The gas radiates heat into the atmosphere. An increase in greenhouse gases has caused the Earth’s energy to increase, hence trapping heat and rising temperatures. Therefore, there is a need to reduce carbon dioxide emissions in the atmosphere to eliminate its effects on global climate change. The good thing is that nature knows how to regulate itself, and it indeed does everything to keep the carbon count in check. This is achieved through carbon sequestration. Let’s delve deeper into carbon sequestration and the ecosystems sequestering most of the carbon in our environment.
What Is Carbon Sequestration?
Carbon sequestrations reduce atmospheric carbon dioxide emissions to slow, reverse, or eliminate its effects on global climate change by capturing and storing it in liquid or solid form. Nature provides carbon sequesters like oceans, animals, trees, grasses, and other plants (through photosynthesis) by absorbing the carbon and converting them into biomasses.
What Ecosystems Naturally Sequester the Most Carbon?
In a nutshell, the marine and coastal ecosystem sequesters most of the carbon released into the environment. To be precise, the tundra is the ecosystem that stores the most carbon per area, followed by seagrass meadows, mangrove forests, and salt marshes.
The carbon that is stored in the coastal and marine ecosystem is referred to as blue carbon. The ecosystem of seagrass, mangroves, and tidal marshes can store more carbon than terrestrial ecosystems found on land.
1. Tundra as a Carbon Sink
In tundra ecosystems, tree growth is hindered by low temperatures. However, it is efficient for storing carbon because of the frozen soil. As a result, the tundra captures carbon dioxide, keeps it from returning to the atmosphere, and accounts for 25% of carbon sink on Earth. However, the tundra carbon sink stores the most carbon per area and is highly threatened by climate changes, and instead of an increase in its capacity, it is absorbing less carbon.
2. Seagrass Meadows as an Ecosystem
Seagrass Meadows is the most productive ecosystem worldwide and an essential part of the marine ecosystem. Like grasslands, seagrass can store a large capacity of carbon in the anoxic water in its leaves, stems, and around the roots. They can absorb twice as much carbon as tropical forests on land per square mile.
According to research, seagrass meadows 0.2% of the world’s ocean is occupied by and stores over 10% of carbon absorbed by the oceans annually.
When the seagrass dies, the carbon is trapped in the sediment, where it can remain trapped for hundreds of years.
3. Mangrove Forests Ecosystem
Although mangroves are disappearing at a rate of 2% per year, they are the 3rd most efficient ecosystem in storing carbon. A mangrove is a shrub or group of trees that grow in the coastal saline.
They grow in brackish water that allows sediments to accumulate and where there is low oxygen in the soil. These trees cannot withstand freezing temperatures, so they grow in tropical or subtropical latitudes.
Mangroves absorb and store most of the carbon through the soil and dead roots. Thus, they have a large capacity to store carbon. As a coastal habitat, they can sequester 14% carbon annually in the global oceans.
The importance of mangrove forests can not be ignored. This is why there are efforts to keep global forest carbon stocks intact by improving forest management.
4. Salt Marshes or Tidal Marshes
Salt marshes are coastal ecosystem wetlands between lands and saltwater brought in by the tides. They contain salt-tolerant plants, and the soil is composed of mud and peat from decomposed plants.
This habitat stores a large capacity of carbon accumulated in more than hundreds of years. When plants on this land die, the mud buries them instead of releasing carbon into the atmosphere. It also absorbs carbon from the atmosphere and traps it beneath the sediment.
Sources of Carbon in the Atmosphere
Carbon dioxide comes from two primary sources- natural and human sources. Natural resources include animal decomposition, respiration, weathering of carbonate rocks, and volcano eruptions.
Human activities are deforestation, fossil fuel combustion, and industrial processes like cement production. According to research, 85 percent of the carbon produced by human activities comes from burning fossil fuels such as coal, natural gas, and oil.
This can be avoided through carbon sequestration, whether artificial or natural. When carbon is captured, it should be stored so that it will not be released back into the atmosphere. There are three common ways to ensure successful carbon sequestration:
- Biological sequestration-This is the most efficient method of capturing carbon. It refers to the storing of atmospheric carbon in woody products, vegetation, and soil. Planting and preserving existing trees and restoring damaged grasslands and wetlands can help enhance biological sequestration.
- Geological sequestration: Refers to capturing carbon from the source and compressing it into liquid form, transport and storing it in underground geological formations. The carbon is injected into porous rocks, essential for holding the carbon and preventing it from entering the air.
- Ocean sequestration– this is where CO2 hydrate is injected into the seafloor. Carbon dioxide is denser than seawater, and it may be possible to store it there. However, this method can cause sea acidification and can be harmful to sea life.
Benefits of Carbon Sequestration to the Environment
The idea behind carbon sequestration is to minimize the moisture that can cause harm to the environment.
- Reduces Global Warming: When extra carbon is emitted and trapped in the atmosphere, it can cause the Earth to heat and become warmer than usual. Thus, this causes increased humidity that can cause illness, drought because of less rain, flooding, and many adverse effects on humans, plants, and animals. Research has shown that about 45% of carbon remains in the air while the rest sequesters naturally.
- Reduction of Ocean Acidification: Studies have shown that the volume of carbon dioxide going into the ocean has increased tremendously in the past years. However, the percentage of emission of 31% absorbed by the ocean has remained relatively the same.
- Prevent Forest Land from Conversion: Since trees are a natural way to sequester carbon, the government is discouraged from converting any preserved land for forests to private land. Instead, forest management should give top priority to tree preservation and encourage people to plant more trees. When carbon sinks are large, the more carbon it captures. About 31 percent of carbon is stored in the biomass (trunk, bark, branches, leaves, and the roots) in the forest, and 69 percent is stored in the soil.
Supplementing the Natural Carbon Sequestration of the Planet
Carbon sequestration is an integral part of the survival of our planet. The largest carbon sequesters are the coastal ecosystems, including the tundra, seagrass meadows, mangrove forests, and salt marshes.
Many oil and gas industries are also exploring their activities in the deep sea, leading to damage and destruction of the ecosystem, decreasing how carbon is absorbed.
There should be coastal ecosystem management to maintain the quality of carbon sinks in coastal ecosystems. Luckily, professional consultancy companies like Melzer Consulting are helping oil field companies determine the best carbon sequestration for their oilfields.