Carbon dioxide and methane as greenhouse gases

Greenhouse gases

  • Greenhouse gases in the atmosphere maintain temperatures on Earth high enough to support life.

The Main Greenhouse Gases(Traps heat into the atmosphere):

  • Water vapour

  • Carbon dioxide -combustion of fossil fuels, deforestation

  • Methane-planting crops, cattle farming

Due to extra amounts of these greenhouse gases, the layer increases and therefore, more heat is trapped.

The average temperature of the Earth increasing is called global warming.

  1. Short-wavelength radiation: Short-wavelength radiation from the Sun (mostly UV and visible light) passes through the transparent atmosphere.

  2. Absorption & Re-emission: The Earth's surface absorbs this radiation and warms up. It then re-emits the energy as long-wavelength (infrared/thermal) radiation.

  3. Trapping Heat: Greenhouse gases in the atmosphere absorb this re-emitted long-wavelength radiation.

  4. Thermal Warming: The gas molecules re-radiate this thermal energy in all directions, including back towards the Earth, trapping the heat and warming the planet.

Human activities which contribute to an increase in greenhouse gases in the atmosphere

Greenhouse Gas

Main Human Sources

Why it Increases

Carbon Dioxide

* Burning fossil fuels


* Deforestation

* Combustion releases locked-up carbon.


* Fewer trees mean less CO2 is removed via photosynthesis.

Methane

* Cattle/Livestock farming


* Landfill sites

* Digestive processes of cows produce methane.


* Decomposition of waste by microorganisms releases methane.

Global climate change

Rising temperatures will increase the melting of ice sheets and glaciers. This leads to increased sea levels. This could lead to more flooding within areas.

Increasing temperatures can change the distribution of animals

Increasing temperatures can lead to decrease of crop yield.

The carbon footprint and its reduction

The carbon footprint is the total amount of carbon dioxide and other greenhouse gases released into the atmosphere by a product, person or process.

Actions to Reduce Carbon Footprint

  • Alternative energy: Switching from fossil fuels to renewable energy sources (e.g., solar, wind, nuclear).

  • Energy conservation: Improving insulation in homes and using energy-efficient appliances.

  • Carbon capture and storage (CCS): Catching CO2 produced by burning fossil fuels before it escapes into the atmosphere, and storing it safely underground.