CARBON DIOXIDE EMISSIONS

Carbon dioxide is a gas which is crucial to support life on this planet . It is exhaled by mammals and is in turn fixed and sequestered by plants . It exists in  small concentrations in earth atmosphere . CO2 is one of the known greenhouse gases. 

A rapid increase in CO2 emissions is observed which is mainly attributed to energy – driven consumption of fossil – fuels  only 280 ppm in pre industrial area whereas in year 2016 it has reached to 403 ppm which is approx. 40% higher as compared to the pre industrial area. 

Sources of carbon dioxide emissions

CO2 emissions : Human Sources 

A)    Human Sources come from activities like cement production, deforestation as well as the burning of fossil fuels like coal, petroleum,  and natural gas.

B)    Fossil Fuel Combustion/ Use : The largest human source of CO2 emissions is from the combustion of fossil fuels . The three types of fossil fuels  that are used the most are : Coal – 43%, Natural Gas – 36% and Oil – 20%.

C)    For every Tonnes of coal burned , approx. 2.5 Tonnes of CO2 are produced.

D)    Main economic sectors that use fossil fuels are ; 

Electricity/ Heat Sector : It produces the largest amount of man- made CO2 emissions in 2010

Transportation sector: It is the second largest source of anthropogenic carbon dioxide emissions. Road transport accounts for 72% AND  apart from road vehicles , the other imp. Sources of emissions for this sector are marine shipping( 14% of CO2 emissions and 1 billion Tonnes of CO2 emissions) and global aviation( 11%).

Industrial sector : Third largest source of man- made CO2 emissions.  It consists of :

E)    Manufacturing include paper , food , petroleum refineries,  chemicals and mineral products…..For e.g. Factories in the cement industry , have to heat up limestone to 1450°C to turn it into cement, which is done by burning fossil fuels to create the required heat.

F)    Construction

G)   Mining 

H)    Agriculture 

I)      Land Use Changes: Land use changes are when the natural environment is converted into areas for human use like agricultural land or settlements. 

J)     Deforestation has been responsible  for the great majority of these emissions.

K)    Industrial Processes: It accounts for 4% of human CO2 emissions and contributed 1.7 billion Tonnes of CO2 emissions in 2011. 

L)     Four main types of Industrial process that are a significant source of CO2 emission: 

# production and consumption of mineral products > cement ( 1000 kg of cement produces nearly 900kg of CO2)

# production of metals such as iron and steel

# production of chemicals

# production of petrochemical products

CO2 Emissions: Natural Sources

The earth’s oceans , soil,  plants, animals and volcanoes are all natural sources of CO2 emissions. Human Sources of CO2are much smaller than natural emissions but they upset the balance in carbon cycle that existed before the industrial revolution.

a)     Ocean – atmosphere  exchange: 42.84%

b)     Plant and animal response: 28.56%

c)     Soil resp. and decomposition: 28.56%

d)     Volcanic eruptions: 0.03%

e)     OCEAN – ATMOSPHERE EXCHANGE: Ocean contain dissolved CO2 , which is released into the air at the sea surface . Annually this process creates about 330 billion Tonnes of carbon dioxide emissions. 

f)      PLANT AND ANIMAL RESPIRATION : CO2 is a by product of the chemical reaction that plants and animals use to produce the energy they need ….220 billion Tonnes of CO2 emissions.

g)     SOIL RESPIRATION AND DECOMPOSITION: Any respiration that occurs below ground is considered soil respiration . Plants roots, bacteria, fungi and soil animals use respiration to create the energy they need to survive but this also produces carbon dioxide  and CO2 is regularly released during decomposition.

h)     VOLCANIC ERUPTIONS : It release magma , Ash,  dust and gases from deep below the earth’s surface one of the gases released is carbon dioxide.

Approaches That Could Remove Or Absorb CO2 In The Atmosphere

1. Better agricultural practices that leave carbon in the ground.
2. Use of Biochar
3. is charcoal used as a soil amendment
4. has the potential to help mitigate climate change via carbon sequestration
5. increase agricultural productivity
6. increase soil fertility of acidity soils(low ph soil)
7. Undertaking afforestation and reforestation.
8. One method that is widely discussed is bioenergy for fuel in combination with carbon capture and storage (BECCS) …this involves the use of plants as fuel.
   

Policies Need To Support Practices That:

1. Successfully keep carbon in the ground 
2. Prevent deforestation
3. Support agricultural practice that sequesters carbon and
4.  Promote sustainable land use practices that reduce emissions
5. We also need a carbon tax
   

Some Of The International Measures Taken To Reduce CO2 Emissions Are Enlisted Below:

1. The Paris Agreement : The Paris Agreement is a legally binding international treaty on climate change. Its goal is to limit global warming to well below 2, preferably to 1.5 degrees Celsius, compared to pre-industrial levels.
2. Kyoto Protocol: The main objective of Kyoto Protocol is to reduce the emission from fossil fuel combustion and from industrial emission.