What is the greenhouse effect?
A layer of greenhouse gases – primarily water vapour, and including much smaller amounts of carbon dioxide, methane and nitrous oxide – acts as a thermal blanket for the Earth, absorbing heat and warming the surface to a life-supporting average of 15 degrees Celsius.
Essentially this process slows the loss of heat to space, keeping the earth’s surface warmer than it would be without the greenhouse gases. Without this “greenhouse” the Earth’s atmosphere would be an average of about 30-35 oC cooler and life as we know it would not exist.
Then what is the enhanced greenhouse effect?
The enhanced greenhouse effect, sometimes referred to as climate change or global warming, is the impact on the climate from the additional heat retained due to the increased amounts of carbon dioxide and other greenhouse gases (GHGs) that humans have released into the earth’s atmosphere since the industrial revolution.
On Earth, human activities are changing the natural greenhouse. Over the last century, the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities has increased concentrations of greenhouse gases.
Anthropogenic factors (Human activities) which lead to the enhanced greenhouse effect:
- Burning of fossil fuels
- Changing land use (Rice cultivation, cattle ranching, etc)
Gases that contribute to the greenhouse effect include:
- The most abundant greenhouse gas, water vapour increases as the Earth’s atmosphere warms, but so does the possibility of clouds and precipitation.
Carbon dioxide (CO2)
- Carbon dioxide is released through both natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels.
- Carbon oxidation is a process by which carbon in the soil reacts with oxygen in the atmosphere to produce CO². Deforestation exposes soil to sunlight which increases the soil temperature.
- Humans have thus increased atmospheric CO2 concentration by more than a third since the Industrial Revolution began.
- To find out about deforestation in the Amazon Rainforest, go here: https://theserangoonview.wordpress.com/2017/02/28/why-is-the-amazon-rainforest-important/
- A hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation.
- Methane is released when dead leaves and manure decompose rapidly in the rice field due to a high level of moisture in the soil.
- Greenhouse gas emissions associated with livestock supply chains (e.g. Cattle farming) account for 14.5% of all human-caused GHG releases, according to a report published by the UN Food and Agriculture Organisation in 2013.
- With increased prosperity, people are consuming more meat and dairy products every year, global meat production is projected to more than double from 2001 to 2050.
- A powerful greenhouse gas produced by soil cultivation practices, especially the use of commercial and organic fertilisers, fossil fuel combustion, nitric acid production, and biomass burning.
- The use of chemical fertilisers increases the amount of nitrous oxide in soil. The nitrous oxide is then released when soil is ploughed or when rain flows through the soil.
- More fossil fuels are burnt to produce energy for household activities in urban areas such as heating, cooking and lighting.
- More cars, buses and other transportation on the roads also increase greenhouse gas emissions.
- Constructing infrastructure and producing construction materials also release Nitrous Oxide into the atmosphere.
- Synthetic compounds entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to the destruction of the ozone layer.
- To see how the ozone layer protects us, go here: http://earth.rice.edu/mtpe/atmo/atmosphere/topics/ozone/o3.html
- For a more detailed explanation of protective ozone, go here: https://disc.gsfc.nasa.gov/ozone/additional/science-focus/about-ozone/ozone_atmosphere.shtml
To understand the consequences of changing the natural composition of atmospheric greenhouse gases, read more here:
Did you know?
What’s it like to have too little or too much of the greenhouse effect? Read below:
Witness the destruction, the crimes, and the exploitation in the Amazon rainforest: http://blogs.reuters.com/photographers-blog/2013/11/11/from-paradise-to-inferno/
Is there hope for our cities? These guys think so: http://www.ucsusa.org/clean-vehicles/vehicles-air-pollution-and-human-health#.WMVBTlV97IU
Read the full articles here:
Leave a reply!
- After watching the video above (from 2:30 – 4:10), what role do Arctic Ice, Clouds, and Water vapour have on controlling the temperature of the earth?
- Compare between the ‘Greenhouse Effect’ and the ‘Enhanced Greenhouse Effect’.
- Explain how deforestation and changing land use worsen the enhanced greenhouse effect.