Greenhouse Effect & Greenhouse Gases

Greenhouse Effect & Greenhouse Gases

• The exchange of incoming and outgoing radiation that warms the Earth is often referred to as the greenhouse effect because a greenhouse works in much the same way.
• Incoming UV radiation easily passes through the glass walls of a greenhouse and is absorbed by the plants and hard surfaces inside.
• Weaker IR radiation, however, has difficulty passing through the glass walls and is trapped inside, thus warming the greenhouse.
• This effect lets tropical plants thrive inside a greenhouse, even during a cold winter.

Green House Effect Contributors 

• Water vapor is the biggest contributor to the greenhouse effect; However CO2 & other greenhouse gases are increasing the amount of water vapors in the air by boosting the rate of evaporation
• Major Contributors: CO2 (Fossil fuels) > CO2 (Deforestation) > CH4 > N2O
• Major Sources: Electricity >Transportation > Industry > Commercial & Residential

• Rate of evaporation rises with temperature, the amount of water vapour at any time is strongly related to the amount of other greenhouse gases in the air.
• Wetlands – largest source of CH4 due to bacteria that decomposes organic material in absence of air
• Globally, Agriculture sector is primary source of CH4 emission via animal manure biogas
• Methane is also the primary constituent of Natural gas
• Black carbon commonly known as soot is a form of particulate air pollutant, produced from incomplete combustion (Consist of pure carbon & strongest absorb er of sunlight)
• Black carbon stays in the atmosphere for only several days to weeks, whereas carbon dioxide (CO2) has an atmospheric lifetime of more than 100 years
• Together, black carbon, methane & ozone are responsible for 30 – 50% of human effects on global warming. However, unlike CO₂which lasts over 100 yrs once released, these pollutants are short lived.

• Project Surya aims to mitigate the regional impacts of global warming by reducing atmospheric concentrations of black carbon, methane, and ozone
• Major co-benefits of reducing these air pollutants will include immediate improvements in public health, agricultural productivity and economic development for the rural populations in developing nations.

Global Warming Potential

• a relative measure of how much heat a greenhouse gas traps in the atmosphere
• compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide
• GWP of Primary CHGs – SF6 > PFCs > HFCs > N2O > CH4 > CO2