Carbon sequestration



UPSC 2017

QUES –  In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be the potential sites for carbon sequestration?
1. Abandoned and uneconomic coal seams
2. Depleted oil and gas reservoirs
3. Subterranean deep saline formations
Select the correct answer using the code given below:
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Answers (d)

Carbon sequestration is both a natural and artificial process by which carbon dioxide is removed from the Earth’s atmosphere and then stored in liquid or solid form.It is a process of capture and deliberate storage of CO2 over a long period of time. The initial purpose of doing this is to delay global warming and avoid extreme climate change.

Image result for carbon sequestration

Other forms of carbon, not just CO2 are also stored during this sequestration process.Once captured, the CO2 is put into long term storage either by storing it in carbon sinks (such as oceans, forests or soils) or underground injection and geologic sequestration into deep underground rock formations.

Types of Sequestration

There are number of technologies under investigation for sequestering carbon from the atmosphere. These can be discussed under three main categories:

1 . Ocean Sequestration: Carbon stored in oceans through direct injection or fertilization.
2 . Geologic Sequestration: Natural pore spaces in geologic formations serve as reservoirs for long-term carbon dioxide storage.
3 . Terrestrial Sequestration: A large amount of carbon is stored in soils and vegetation, which are our natural carbon sinks. Increasing carbon fixation through photosynthesis, slowing down or reducing decomposition of organic matter, and changing land use practices can enhance carbon uptake in these natural sinks.

Carbon sequestration and climate change

In response to growing concerns about climate change resulting from increased carbon dioxide concentrations in the atmosphere, considerable interest has been drawn to the possibility of increasing the rate of carbon sequestration through changes in land use and forestry and also through geoengineering techniques such as carbon capture and storage.

Carbon dioxide (CO2) is naturally captured from the atmosphere through biological, chemical, and physical processes. Artificial processes have been devised to produce similar effects, including large-scale, artificial capture and sequestration of industrially produced CO2 using subsurface saline aquifers, reservoirs, ocean water, aging oil fields, or other carbon sinks.