Page 8 - LECTURETTE TOPICS eBOOK

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TOPIC -1

Global warming

Quick points to remember

• Global warming or climate change is mainly caused by greenhouse gases.

• The major greenhouse gas is carbon dioxide, other significant one being
methane.
• The United States of America is responsible for around 25 percent of the
total carbon dioxide emitted into the atmosphere.
• The average temperature of Earth has increased by 1.4 degrees
Fahrenheit from the last century.
• The temperature in the Arctic region has seen an increase of almost
double the global average.
• The wildlife has been hit hard by global warming as indigenous creatures
like polar bears and coral reef are dwindling fast in number.

Introduction
Global warming is one of the most alarming and sensitive issues of the past and
present decade. It is characteristically defined as an increase in temperature of the
atmosphere and water bodies of Earth. Gradually, it is showing drastic effects on its
climate. One of the main reasons for this cataclysmic change is the increased
amount of emission of greenhouse gases, led by carbon dioxide, which traps the
heat in the Earth's atmosphere, making it warm. These greenhouse gases are
necessary to keep the temperature of the planet from falling below freezing levels,
but an excessive amount of it has had negative effects due to increased retention of
heat. The increased amount is mainly due to excessive burning of fossil fuels,
deforestation, distorted agricultural practices and destructive human activities. Some
call it a hoax, saying it is a periodic phenomenon that happens cyclically over a period
of time, but the alarming rise in temperature and the rapid melting of ice caps have
got everyone worried of its actual potential.

Current scenario

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