Topic 1: Global Warming and Climate Change
Objectives:
· To understand who is the main contributor to global warming.
· To be able to list advantages and disadvantages to greenhouse gases.
· To be able to point out examples of climate change as a result of
global warming.
Slide 4 Introduction:
Many of us know we have to recycle, reuse and limit the use of earth’s resources- but why do we need to do these actions?
Examples: recycle paper, use solar energy (using less electricity), use public transportation more and drive less
Slide 5, 6 It is evident that climate change is occurring as many places have seen changes in rainfall pattern- resulting in more floods, droughts, or intense rain, as well as more frequent and severe heat waves. Global warming is a type of climate change- which leads to melting of ice caps, warming of oceans and rising of sea levels.
[Refer to next slide (Real Life Examples)]
Slide 7 As observed by many scientific studies across the globe, it is clear that global average temperature is on the rise and it is very likely due to human activities. Since the beginning of the Industrial Revolution, burning of fossil fuels has contributed to the increased concentration of greenhouse gases (GHG), mainly methane (CH4) and carbon dioxide (CO2).Greenhouse gases are atmospheric gases (including CH4, CO2, water vapour, nitrous oxide (N2O), ozone (O3)).
Slide 8, 9 Greenhouse gases are needed for survival of humans and many marine and terrestrial organisms. If greenhouse gases are not present, the earth would be too cold (33 degrees Celsius colder than current average temperature). However, when the greenhouse gases concentration become too high, they will make the earth too hot and contribute to global warming. As seen in slide 9, many cities in 2014 reached its hottest record temperature- such as Sydney, Australia reaching 45.8 degrees Celsius. The global temperature of May 2014 is the hottest on record.
Slide 10 One of the consequences of global warming is the rising of sea levels, which will at first affect coastal low-lying areas, including many big cities (like Hong Kong) with a high population density. In fact, some island nations such as Maldives and Tuvalu are already facing the threat of inundation.
Slide 11, 12 Several contributors to global warming are deforestation, industrial buildings and transportation means such as cars, trucks, trains and airplanes.
Many people would think the main contributor to global warming would be pollution from transportation vehicles. However, global livestock industry contributes 14.5% to GHG emissions with transportation industry sitting at 13%.
Slide 13 How do the animals produce so much GHG emissions? Animal feces generate nitrous oxide, a greenhouse gas with 296 times the warming effect of carbon dioxide. In addition, methane, which is emitted from cows through belching and flatulence has a global warming effect that is 21 times more powerful than carbon dioxide.
The amount of CO2 generated per 1kg protein produced is shown. Production of 1kg of protein coming from beef produces 27 kg of CO2; 1 kg of protein from pork produces 12 kg CO2and 1 kg protein from tofu only produces 2 kg CO2.
Slide 14 Not only does animal produce greenhouse emissions through their belching and flatulence, the food or animal production process also generate a high amount of greenhouse gases. This would include production methods, food waste, packaging and delivery of the animal products. The chart lists the amount of carbon dioxide equivalents (in kg) that 1 kg of food or animal products generates.
Since meat production create so much pollution, should we consider decreasing consumption of meats?
A few suggested questions:
Ø What are some main contributors of greenhouse gases?
Ø What kind of climate changes is occurring?
Ø Why are greenhouse gases important for earth?
Ø What are some environmental impacts of climate changes and global warming?