Page 2 - 2. Lesson notes- Bio- geo chemical cycles-2

1.Effects on Human Health

The humans will be directly exposed to the harmful ultraviolet radiation of the sun due to the
depletion of the ozone layer. This might result in serious health issues among humans such as

skin diseases, cancer, sunburns, cataract, quick aging, and weekend immune system.

2. Effects on the Environment
Strong ultraviolet rays may lead to minimal growth, flowering, and photosynthesis in plants. The

forests also have to bear the harmful effects of the ultraviolet rays.
3. Global warming

Global warming is the ongoing rise in the average temperature of the Earth's climate.
Greenhouse effect (GHE)

Greenhouse effect

Step 1: Solar radiation reaches the Earth's atmosphere - some of this is reflected back into
space.

Step 2: The rest of the sun's energy is absorbed by the land and the oceans, heating the Earth.
Step 3: Heat radiates from Earth towards space.

Step 4: Some of this heat is trapped by greenhouse gases in the atmosphere, keeping the
Earth warm enough to sustain life.

Step 5: Human activities such as burning fossil fuels, agriculture and land clearing are

increasing the amount of greenhouse gases released into the atmosphere.
Step 6: This is trapping extra heat, and causing the Earth's temperature to rise.

Greenhouse gases:-

Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range
emitted by Earth.

Ex-Carbon dioxide (0.04%), nitrous oxide, methane and ozone are gases that contribute to the
greenhouse effect.