Carbon Sources & Sequestration

Carbon sink & source

A carbon sink is anything that absorbs more carbon that it releases, while a carbon source is anything that releases more carbon than is absorb

Forests, soils, oceans and the atmosphere all store carbon and this carbon moves between them in a continuous cycle. This constant movement of carbon means that forests act as sources or sinks at different times.

Natural sinks → Oceans (Largest on earth) + Photosynthesis by plants

Artificial sinks → Landfills + Carbon capture and storage proposals

Oceans are the largest active carbon sink on Earth, absorbing more than a quarter of the carbon dioxide that humans put into the air.

long-term storage of carbon dioxide to mitigate global warming & avoid dangerous climate change
proposed as a way to slow the atmospheric and marine accumulation of greenhouse gases
includes carbon capture and storage, which refers to large-scale, permanent artificial capture & sequestration of industrially produced CO2 using

Subsurface saline aquifers

Reservoirs

Ocean water

Aging oil fields or other carbon sinks

The method of geo-sequestration or geological storage involves injecting carbon dioxide directly into underground geological formations for ex :

Declining oil fields

Saline aquifers

Unminable coal seams

CO₂has been injected into declining oil fields for more than 40 years, to increase oil recovery
CO₂is soluble in oil hence lowers viscosity of the oil & reduces its interfacial tension which increases the oils mobility.
Salty water contained in deep saline aquifers is not suitable for drinking or agriculture, making saline aquifers an ideal large-scale storage solution for large stationary industrial CO2 emitters.
Unminable coal seams can be used to store CO₂, because CO₂absorbs to the coal surface, ensuring safe long-term storage.
In this process it releases methane that was previously adsorbed to the coal surface and that may be recovered, & Again the sale of the methane can be used to offset the cost of the CO₂storage

Any tradable certificate representing the right to emit one tonne of carbon dioxide or the mass of another greenhouse gas equivalent to one tonne of carbon dioxide
Carbon credits and carbon markets are a component of national and international attempts to mitigate the growth in concentrations of greenhouse gases (GHGs)
One carbon credit is equal to one tonne of carbon dioxide, or in some markets, carbon dioxide equivalent gases.
Carbon offsetters purchase the credits from an investment fund or a carbon development company that has aggregated the credits from individual projects
Buyers and sellers can also use an exchange platform to trade, such as the Carbon Trade Exchange, which is like a stock exchange for carbon credits
China is currently the largest seller of carbon credits controlling about 70% of the market share with India at second place with 20% market share
MCX has become the first exchange in Asia to trade carbon credits

A carbon offset is a reduction in emissions of carbon dioxide or greenhouse gases made in order to compensate for or to offset an emission made elsewhere
Carbon offsets are measured in metric tons of carbon dioxide-equivalent (CO₂e) and may represent six primary categories of greenhouse gases: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF₆)
One carbon offset represents reduction of one metric ton of carbon dioxide or its equivalent in other greenhouse gases

a tax based on greenhouse gas emissions (GHG) generated from burning fuels
Basically a tax on fossil fuels, especially those used by motor vehicles, intended to reduce the emission of carbon dioxide
puts a price on each tonne of GHG emitted, sending a price signal
India Doesn’t like it & is against carbon tax from goods imported from India to other countries