- Nitrogen (78%)
- Oxygen (21%)
- Carbon dioxide (0.03%)
- Noble gases (less than 1%, mainly argon)
- Water vapour (variable)
Category: Atmosphere
Describe the potential effects of the increased levels of greenhouse gases like carbon dioxide and methane.
Increased greenhouse gas concentrations trap more heat in the Earth’s atmosphere, causing the average temperature on Earth to increase. This phenomenon is known as global warming. Global warming can result in more extreme weather events and the melting of polar ice.
1. Melting of ice caps and glaciers
The rising temperatures can cause ice caps and glaciers to melt, resulting in rising sea levels and increased flooding in low-lying coastal regions.
2. Extreme weather events
The rising temperatures can cause changes in precipitation patterns, resulting in more intense and frequent rainfall in some regions and more frequent and severe droughts in other regions. There will be more frequent and intense heat waves, droughts and extreme weather events like hurricanes and floods.
What are greenhouse gases? What are the sources of these greenhouse gases?
Greenhouse gases are gases that trap heat in the Earth’s atmosphere. Examples of greenhouse gases are carbon dioxide and methane. Too much of these greenhouse gases can result in global warming.
The sources of these gases:
1. Carbon dioxide
Carbon dioxide is released to the atmosphere mainly through the combustion of carbon-containing fuels, and the respiration of living organisms.
2. Methane
Methane is released to the atmosphere mainly through the decomposition of organic matter and from flatulence from livestock like cows, goats.
Catalytic Converter
Explain how combustion engines produce nitrogen oxides.
Fuels are combusted in internal combustion engines, producing a lot of heat.
The high temperature condition causes oxygen and nitrogen in the air to react to form oxides of nitrogen.
What is the source of sulfur dioxide, and the harmful effects of sulfur dioxide?
The source of sulfur dioxide comes from burning of fossil fuels, and volcanic activity.
Sulfur dioxide can dissolve in rain water high up in the atmosphere, forming acid rain.
Acid rain speeds up the corrosion of buildings and structures made of limestone or reactive metals, like steel.
Acid rain makes water too acidic, which can be harmful to aquatic organisms.
Acid rain removes essential metal ions needed by plants, such as calcium, potassium, magnesium ions from the soil, affecting the health of plants.
List the 3 consequences of global warming.
Melting of ice in the polar ice caps, mountain glaciers, resulting in the rise in sea level, resulting in flooding of low lying regions.
Increase in average global temperatures
Climate change, resulting in an increase in extreme weather conditions, like heat waves and droughts
What is the importance of the ozone layer?
The ozone layer filters out some of the harmful UV radiation from the sun, reducing the amount of harmful UV rays reaching the Earth’s surface.
The harmful UV radiation can cause skin cancer, genetic mutations, eye damage, and is harmful to marine life.
Burning biodiesel as a fuel is considered to be a “carbon neutral” activity. Explain what is meant by “carbon neutral” in this context.
The source of biodiesel is from plant parts. During the growth and development of these plants, they absorb carbon dioxide from the environment for photosynthesis. During the combustion of biodiesel, the same amount of carbon dioxide is released to the environment.
The net amount of carbon added to the environment from the burning of biodiesel is considered to be zero, hence “carbon neutral”.
What are the harmful effects of acid rain?
Acid rain speeds up the corrosion of buildings and structures made of limestone or reactive metals, like steel.
Acid rain makes water too acidic, which can be harmful to aquatic organisms.
Acid rain removes essential metal ions needed by plants, such as calcium, potassium, magnesium ions from the soil, affecting the health of plants.