Experiment 1 : Global Warming

Target Audience: Polytechnic Teachers and Students in Tamilnadu
Subject: Life and Employability Skill Practical, M scheme, 4th and 5th Semester
Objectives: To improve the listening and note taking skill of the students
Question Pattern in Exam: Listen to the following passage and take notes / hints (10 marks)
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 Experiment 1

Listen to the following passage read out to you and take down notes/hints:

                                                            Global Warming

Global warming is the unusual rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels. The global average surface temperature rose 0.6 to 0.9 degrees Celsius (1.1 to 1.6° F) between 1906 and 2005, and the rate of temperature increase has nearly doubled in the last 50 years.

The cause of global warming is the increasing quantity of greenhouse gases such as carbon-di-oxide, methane and nitrous oxide in our atmosphere produced by human activities, like the burning of fossil fuels, deforestation, smoke from vehicles and factories. The majority of man-made carbon dioxide emissions is from the burning of fossil fuels such as coal and oil so that humans can power various vehicles, machinery, keep warm and create electricity. Since the Industrial Revolution began in about 1750, carbon dioxide levels have increased nearly 38 percent as of 2009 and methane levels have increased 148 percent.

Greenhouse gases trap heat in the Earth's atmosphere to keep the planet warm enough to sustain life, this process is called the greenhouse effect.  Without this, the Earth would be too cold for humans, plants and other creatures to live. However, higher levels of these gases trap more heat and the temperature of earth increases more and more.

The impact of global warming is far greater than just increasing temperatures. Current research is also showing that the water cycle is changing and rainfall patterns are shifting to make areas that are already dry even drier. This is causing water shortages and an intense amount of distress to the over 2.5 million people in dry regions which are degrading into desert. This process is called desertification. Perennial ice cover in the Arctic is melting at the rate of 11.5% per decade and the thickness of the Arctic ice has decreased by 48% since the 1960s. Since 2010, the Antarctic ice melt rate has doubled. The Earth's sea level has risen by 21 cm (8 inches) since 1880. Power Dissipation Index which measures the destructive power of tropical cyclones has increased in the Pacific by 35% and in the Atlantic it has nearly doubled.

Based on plausible emission scenarios, average surface temperatures could rise between 2°C and 6°C by the end of the 21st century.

Notes on Global Warming

1.       Definition of global warming

1.1.  Rapid increase in Earth’s Temperature

1..1.1 . 0.6 to 0.9  ͦC (1906-2005)

1.1.2.  double in last 150 years

       2.   Causes of Global Warming

                2.1. Increasing Green House gases: Carbon-di-oxide, methane, nitrous oxide

                2.2  Human activities such as

                                2.2.1. burning of fossil fuels(for vehicles, machinery & electricity)

                                2.2.2. deforestation

                                2.2.3. smoke from vehicles and factories

                2.3.Due to Industrial Revolution (1750)

                                2.3.1. increase of Co2 by 38%

                                2.3.2 increase of CH4 by 138 %

       3.  Greenhouse Effect

                3.1. helping Earth to keep warm

                3.2. a must for survival of lives on earth

                3.3. higher level of greenhouse gases being dangerous  for lives

      4.   Impact of Global Warming

                4.1. Desertification

                                4.1.1. change in rainfall patterns

                                4.1.2. water shortages to 2.5 million people in dry regions

                4.2. Melting of Ice cover

                                4.2.1. in Arctic 11.5% per decade & 48% since 1960

                                4.2.2  in Antarctic, doubled since 2010

                4.3. Rising of Sea Level 21 cm since 1880

                4.4. Cyclone rise in pacific by 35% in pacific & double in Atlantic.

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The teacher can also play the following videos for better understanding of the students on global warming: