Question

What is meant by the term carbon sequestration?

Short answer

Carbon sequestration is the process of capturing and storing atmospheric CO2 to mitigate climate change.

Step-by-step solution

Understanding Carbon Sequestration

Carbon sequestration refers to the process of capturing and storing atmospheric carbon dioxide. It is a method used to reduce the amount of CO2 in the atmosphere with the goal of reducing global climate change.

Types of Carbon Sequestration

There are primarily two types of carbon sequestration: biological and geological. Biological sequestration involves storing carbon in plants, soil, and oceans while geological sequestration involves storing carbon underground in rock formations.

Mechanisms of Biological Sequestration

In biological sequestration, plants absorb CO2 during photosynthesis and store it in their biomass and the soil. Forests, grasslands, and wetlands play a crucial role in this process.

Mechanisms of Geological Sequestration

In geological sequestration, CO2 is captured, compressed, and injected into deep underground rock formations. This is usually under high pressure where the CO2 is trapped between rock layers.

Key concepts

Biological Sequestration

Biological sequestration is nature's way of storing carbon dioxide. It involves using plants, soils, and oceans to capture and store this greenhouse gas. Through biological processes, organisms like trees and oceanic plankton absorb and store carbon.

• **Plants** take in CO2 from the atmosphere during photosynthesis and store it in their leaves, stems, and roots.
• **Soils** also capture and store organic carbon from decaying plant material and microorganisms.
• **Oceans** act as significant carbon sinks, with marine plants and organisms like algae absorbing CO2.

The effectiveness of biological sequestration varies, as factors like soil type, vegetation, and land use can influence the amount of carbon stored.

Geological Sequestration

Geological sequestration involves capturing carbon dioxide and storing it safely deep underground. This process helps mitigate climate change by storing CO2 away from the atmosphere. Here’s how it works:

• **Capture:** CO2 is captured from industrial or energy-related sources like power plants.
• **Compression:** The gas is compressed into a liquid state to facilitate its underground injection.
• **Injection:** The CO2 is then injected into rock formations that hold the gas.
  • These formations consist of spaces between rocks and are often found in areas used for oil and gas production.
• **Storage:** Once injected, the CO2 is stored securely in geological formations where it can be retained for thousands of years.

Geological sequestration is considered a reliable method because these formations can hold CO2 permanently.

Carbon Dioxide

Carbon dioxide (CO2) is a colorless gas which is vital for life on Earth. It plays a significant role in the carbon cycle, consisting of various natural processes that capture and release carbon. However, excessive CO2 emissions from human activities contribute significantly to global warming. Let's take a closer look:

• **Natural Sources:** Volcanic eruptions, respiration, and decay of organic matter release CO2 naturally into the atmosphere.
• **Human Activities:** Burning of fossil fuels like coal, oil, and natural gas increases the concentration of CO2.
• **Global Warming Impact:** More CO2 leads to a stronger greenhouse effect, trapping heat and causing Earth's temperature to rise.

Understanding and reducing CO2 emissions is crucial for mitigating the impacts of climate change.

Photosynthesis

Photosynthesis is a process by which plants, algae, and some bacteria convert light energy into chemical energy. It's essential for life on Earth as it provides oxygen and organic compounds that sustain the food chain. Here’s how photosynthesis works:

• **Light Absorption:** Plants capture sunlight using chlorophyll, the green pigment in leaves.
• **Carbon Intake:** CO2 from the air enters plants through small pores called stomata.
• **Chemical Reaction:** Using sunlight, water ( H_2O ), and CO2, plants produce glucose ( C_6H_{12}O_6 ) and oxygen ( O_2 ).
• **Energy Storage:** The glucose produced provides energy for the plant's metabolism and growth.

Photosynthesis not only supplies oxygen but also plays a key role in biological sequestration by storing carbon in plants.