CLIMATE CHANGE MITIGATION STRATEGIES :
Carbon sequestration:
It is the process of capturing and storing atmospheric carbon dioxide. It is one of the methods of reducing the amount of carbon dioxide in the atmosphere with the aim of lighting climate change. There can be two major types of carbon sequestration:
Biological: Biological carbon sequestration is the storage of carbon dioxide in vegetation such as grasslands or forests as well as in soils and oceans.
- Plant rich landscapes like forest, grassland etc. capture 25% of the global carbon emission.
- Soil can store carbon in the form of soil organic carbon soil can also store carbon as carbonates.
- Colder and nutrient rich part of the ocean can absorb more carbon dioxide than warmer parts. Therefore, Polar Regions generally serve as carbon sinks.
Geological carbon sequestration: It is the process of storing carbon dioxide in underground geological formations or rocks.
- Naturally carbonates are created over thousands of years when carbon dioxide dissolves in water and percolates in soil , combining with calcium and magnesium minerals, forming ‘caliche’ in desert and arid soil.
- Artificially, CO2 captured from industrial or any other sources may be injected into porous rocks for long term storage
Hydrodynamic Trapping: It refers to a time dependent hydrogeological process where injected CO2 is effectively trapped by the existence of very long travel times to the surface.
Solubility trap: CO2 dissolved in liquid like water or oil.
Mineral carbonation: CO2 can be made to react to naturally occurring minerals to form stable compound which can stay like that for years (e.g Calcium Carbonate)
Technological carbon sequestration: These are the new ways being explored by scientists to capture and store carbon using innovative technologies and to make useful products out of it.
- Direct air capture: capturing carbon directly from air using advanced technology plants. For now the technology is highly expensive and energy intensive. But with more advancement in technologies, this may become a viable option.
- Engineering molecules: These molecules can change shape by creating new kinds of compounds capable of singling out and capturing carbon dioxide from the air.
Carbon Sink (Green and Blue Carbon):
Green carbon: It is the carbon which is stored by vegetation (forests, grasslands, etc.) It is basically biological carbon sequestration. Reforestation and Afforestation are mechanisms to enhance green carbon.
Blue carbon: Carbon stored by coastal, aquatic or marine ecosystems. These include mangroves, sea grasses etc.
Note : Coastal ecosystems are more efficient carbon sinks when compared to tropical rainforests.
Carbon credit and carbon offsetting :
Carbon pricing (including tax): Carbon pricing is a method which captures the external cost of greenhouse emission i.e. the losses to different sectors like agriculture, health, property etc. Due to the addition of greenhouse gas in the atmosphere. There are two major types of carbon pricing –Emission Trading system (or cap and trade system) and Carbon Tax.
Advantages of carbon pricing : Shifts the cost on polluters >= internalise the external cost of pollution.
Carbon tax is a potential alternative to the cap and trade method currently used by the Kyoto protocol to reduce carbon emission. A carbon tax aims to internalise the externality of climate change by setting a price on the carbon content of energy consumed or greenhouse gas emitted in the production of consumption of goods.
Advantages of carbon taxes over Quantitative limits or ‘cap and trade’ system :
- Avoids the problem of choosing a baseline.
- Better adaptation to element of uncertainty which pervades the science of climate change.
- Less volatility and more predictability.
- Less administrative arbitrariness-easier implementation-lack of manipulation.
- Addresses the problem of equity.
- Carbon tax will essentially be a pigovian tax which balances the marginal costs and benefits of additional emissions, thereby internalising the cost of environmental damage.
- Better understandability : the carbon tax is simpler to understand and therefore may be braced by more people.
Limitations of Global carbon tax:
- No CBDR.
- Taxes are part of national social contract that emerge out of very specific conditions that can’t necessarily be replicated on a global scale.
Carbon tax can be a solution to India’s air pollution scenario :
- It will provide more revenue to GoI to invest in the renewable energy sector.
- It will force large energy users to look for greener alternatives.
- It will provide more employment opportunities as employment elasticity in greener forms of energy is higher than those in fossil substitutes.
- The carbon pricing leadership coalition is a voluntary initiative that catalyses action towards the successful implementation of carbon pricing around the world. The CPLC brings together leaders from governments,businesses,civil society and academia to support carbon pricing , share experiences and enhance the global ,regional , national and sub national understanding of carbon pricing. The CPLC secretariat is administered by the World Bank Group.
Geo engineering/ Climate engineering/carbon capture technologies:
Geo engineering is a theoretical concept which aims to modify and cool the environment to defeat global warming. It may involve reduction of sunlight reaching earth or absorption of CO2 to reduce global warming. (carbon capture technologies)
Methods to reduce sunlight reaching earth :
- Injecting the atmosphere with sulphur/ hydrogen sulphide
- Copying a volcano
- This method will scatter sunlight and will prevent heating of the earth.
- Putting large mirrors in space
- Reflect light and reduce heating of earth.
- Using wind powered motors to whiten the cloud by spraying water into the sky. This cloud will reflect solar radiation.
Carbon Capture and storage (CCS) technologies or carbon capture utilisation and storage (CCUS) technologies :
CCUS technology is designed to capture CO2 emissions from combustion of fossil fuels. The process starts with capture of CO2 which under a compression process to form a dense fluid. This eases the transportation and storage of the captured CO2. This dense fluid is transported via pipelines and then injected into the underground storage facilities, it can also be used as a raw material in other industrial processes such as bicarbonate.
Other carbon capture technologies:
- Seeding the sea with iron: Phytoplankton prefer iron and flourish in its presence, thus absorbing a lot of CO2. g LOHAFEX was an Indo German ocean iron fertilisation project. It was later halted because of protest from the environmentalists.
- Building fake trees: It may contain compounds which can react with CO2 to absorb it and store it in solid form.