Green House Effect and Gases

  Carbon Cycle

The discussion of Global Warming should and always starts with the carbon cycle as the changes in this cycle is the main cause of global warming.

Carbon Cycle - Components

Atmosphere carbon dioxide and methane, carbon dioxide reacts with water molecules and forms carbonic acid, human activities, released by plant respiration

Terrestrial biosphere - carbon stored in soils, in plants and other living organisms, released by combustion and respiration

The Oceans - including dissolved inorganic carbon and living and non-living marine biota. The sediments calcium carbonate, including fossil fuels

Oceans important role in CARBON SEQUESTRATION (a natural or artificial process by which carbon dioxide is removed from the atmosphere and held in solid or liquid form)

Nature has appropriate balance for everything, but changes occur when anthropogenic changes exceed the carring capacity the buffring capacity of Earth. The main cause for Global Warming is Green House Effect.




  Green House Effect

The greenhouse effect refers to circumstances where the short wavelengths of visible light from the sun pass through a transparent medium and are absorbed, but the longer wavelengths of the infrared re-radiation from the heated objects are unable to pass through that medium. The trapping of the long wavelength radiation leads to more heating and a higher resultant temperature.

In simple words; sunlight having very high energy (means short wavelength) enters earth get reflected back as long wave low energy radiation. The Green house gases (GHGs) trap the outgoing long wave solar radiation in earth. As the concentration of GHGs is increasing the heating capacity is also increasing thus causing an increase in local as well as global temperature called Global Warming.

Natural Green House Effect

The greenhouse effect is the natural process by which the atmosphere traps some of the Sun's energy, warming the Earth enough to support life

Manmade Green House Effect

There is also the "man-made" greenhouse effect, which is the enhancement of Earth's natural greenhouse effect by the addition of greenhouse gases from the burning of fossil fuels and other anthropogenic activities

Gases that have the ability or nature to trap heat in the atmosphere are called greenhouse gases



Example : Car and a green house used to grow plants.

Origin of Green House

The word green house has come from the very idea of growing plants in a plastic or glass enclosure in colder areas

  Green House Gases (GHGs)

Major Green House Gases (listed in Kyoto Protocol internationally accepted)

  1. Carbon dioxide (CO2)
  2. Methane (CH4)
  3. Nitrous oxide (N2O)
  4. Hydrofluorocarbons (HFCs)
  5. Perfluorocarbons (PFCs)
  6. Sulphur hexafluoride (SF6)


Water vapourr are also a major green house gas but as its life is very short thus not considered in this list.

  Sources of GHGs

Carbon dioxide (CO2) - Fossil fuel use is the primary source of CO2. The way in which people use land is also an important source of CO2, especially when it involves deforestation. Land can also remove CO2 from the atmosphere through reforestation, improvement of soils, and other activities. We are releasing more and mor CO2 by fossil fuels and reucing the sequestration process by cutting forests.

Methane (CH4) - Agricultural activities, waste management i.e mainly landfill gas, livestock and energy use all contribute to CH4 emissions

Nitrous oxide (N2O) - Agricultural activities, such as fertilizer use, are the primary source of N2O emissions

Fluorinated gases (F-gases) - Industrial processes, refrigeration, and the use of a variety of consumer products contribute to emissions of F-gases, which include Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), and Sulfur hexafluoride (SF6)

Black carbon (BC)/ Soot is a solid particle or aerosol, not a gas, but it also contributes to warming of the atmosphere. However, it traps the short wave solar radiation rathe than long wave trapped by GHGs. Either ways the temperature of Earth increases.

Global GHG Emissions : As per IPCC 2014; based on global emissions from 2010. (IPCC stands for Intergovernmental Panel on Climate Change)




CO2 from fossil fues burning is still the major cause of GH Effect and Global Warming followed by methane which is increasing tremendously.


  Major activities responsible for GHG Emissions

Energy Supply

The burning of fossils fuels i.e. coal, natural gas, and oil for electricity and heat is the largest single source of global greenhouse gas emissions into the atmosphere


Greenhouse gas emissions from industry primarily involve fossil fuels burned on-site at facilities for energy. This sector also includes emissions from chemical, metallurgical, and mineral transformation processes not associated with energy consumption.

Land Use, Land-Use Change, and Forestry (LULUCF)

Greenhouse gas emissions from this sector primarily include carbon dioxide (CO2) emissions from deforestation, land clearing for agriculture, and fires or decay of peat soils. This estimate does not include the CO2 that ecosystems remove from the atmosphere.


Greenhouse gas emissions from agriculture mostly come from the management of agricultural soils, livestock, rice production, and biomass burning


Greenhouse gas emissions from this sector primarily involve fossil fuels burned for road, rail, air, and marine transportation. Almost all (95%) of the world's transportation energy comes from petroleum-based fuels, largely gasoline and diesel

Commercial and Residential Buildings

Greenhouse gas emissions from this sector arise from on-site energy generation and burning fuels for heat in buildings or cooking in homes

Waste and Wastewater

The largest source of greenhouse gas emissions in this sector is landfill methane (CH4), followed by wastewater methane (CH4) and nitrous oxide (N2O). Incineration of some waste products that were made with fossil fuels, such as plastics and synthetic textiles, also results in minor emissions of CO2

  Global GHG emissions by Economic Sectors

 As per IPCC 2014

Energy Sectors always ranks first in GHG emission but now is very close to Agriculture, Forestry and LULUCF  followed by industries and transport sector.


  Emission by Countries

As per 2011 global emission data; the emission mainly considered usage of fossil fuels combustion and some industrial processes

China is ranks first followed by US and EU. India though have very less emission but is increasing due to developmental activities.