VPE 511: Environment and Environmental Hygiene (2+1)

GLOBAL WARMING AND ITS EFFECTS

Global warming

• Thermal expansion of ocean and melting of glaciers and polar ice sheets and increase in sea level.
• Increase in sea level at the rate of 1 to 2 mm/yr during 20^th Century.
• Increase by 3⁰C would increase the see level by 0.2 to 1.5 meters over the next 100 years.
• 1 meter rise of sea level will inundate many cities like Sydney, Cairo, Bangkok etc.
• Negative impact on human settlements, fisheries, tourism, agriculture and coastal ecosystems.

Effects of global warming

• Change of weather and climate
• In the 20^th century, the global temperature increased by 0.6⁰C.
• Earth’s mean temperature may increase by 1.5 to 5.5⁰C by 2050.
• The moisture carrying capacity will increase.
• The temperature of the troposphere will increase, whereas the temperature of stratosphere will decrease.
• This causes more rain at higher latitudes and less at lower latitudes.
• Extreme drought and floods will be increased.
• In tropical and subtropical areas, human diseases will be increased.
• Rise in Sea level

Effects on living organisms

• Distribution pattern of organisms changes and many species will shift to mountain areas.
• Rapid rise in temperature leads to the trees to die and it would result in creation of scrub vegetation.
• Many species disappear due to inability to migrate fast.

Effects on agriculture

• Increase in plant diseases, pests and weeds resulting in the reduction of crop productivity.
• In temperate region, small increase in temperature may increase crop production but more temperature decreases the crop productivity.