6.+The+Issue+of+global+warming

[] Objectives and page references can be found in the document below! and the word version: __**Topic 6: The issue of global warming (6 hours)**__ This topic allows the study of a controversial global issue in more depth. Opinion within scientific and political communities is divided on this issue, and students should be encouraged to develop a personal viewpoint having considered the arguments. ** TOK: ** This topic directly and usefully challenges popular views of certainty within the sciences. If the scientific community has access to such certainty, how can it be as publicly divided as it has been in this case? What effect does a highly sensitive political context have on objectivity? Can politicians exploit the ambiguity of conclusions coming from the scientific community to their own ends? ** Int: ** This issue involves the international community working together to research and reduce the effects of global warming.

** 6.1.1 Describe the role of greenhouse gases in maintaining mean global temperature. **  The greenhouse effect is a normal and necessary condition for life on Earth. Consider carbon dioxide (CO 2 ) levels in geological times.

 ** 6.1.2 Describe how human activities add to greenhouse gases. **



 Water, CO 2, methane and chlorofluorocarbons (CFCs) are the main greenhouse gases. Human activities are increasing levels of CO 2, methane and CFCs in the atmosphere, which may lead to global warming.

** 6.1.3 Discuss qualitatively the potential effects of increased mean global temperature. ** Consider the potential effects on the distribution of biomes, global agriculture and human societies. Students should appreciate that effects might be adverse or beneficial, for example: expansion of the oceans and melting of the polar ice caps



Read the article about Coral reef ecosystems and then answer the following questions. 1) Between which temperatures do coral reefs usually occur 2) What is coral bleaching? 3) What is thought to be the principal cause of coral bleaching 4) What is symbiosis? 5) Draw a simplified food chain showing the energy flows in a reef ecosystem 6) Why is the outer edge of the reef generally the most productive section of the coral reef?

** 6.1.4 Discuss the feedback mechanisms that would be associated with an increase in mean global temperature. ** For example: in tropical latitudes leading to increased snowfall on the polar ice caps, which reduces the mean global temperature of permafrost, leading to an increase in methane levels, which increases the mean global temperature. <span style="color: #1a1a18; display: block; font-family: 'Comic Sans MS'; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">Any feedback mechanisms associated with global warming may involve very long time lags. <span style="color: #1a1a18; display: block; font-family: 'Myriad Pro'; font-size: 9.5px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">6** .1.5 Describe and evaluate pollution management strategies to address the issue of global warming. ** <span style="color: #1a1a18; display: block; font-family: 'Comic Sans MS'; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">Students should consider the following strategies: <span style="color: #1a1a18; display: block; font-family: 'Comic Sans MS'; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">international agreements (for example, Kyoto Agreement and subsequent updates), carbon tax and carbon trading, alternative energy sources lifestyle in the context of local greenhouse gas emissions [] Students should evaluate these strategies with regard to their effectiveness and the implications for MEDCs and LEDCs of reducing CO 2 emissions in terms of economic growth and national development. <span style="color: #1a1a18; display: block; font-family: 'Myriad Pro'; font-size: 9.5px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">** 6.1.6 Outline the arguments surrounding global warming. ** <span style="color: #1a1a18; display: block; font-family: 'Myriad Pro'; font-size: 9.5px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;"> <span style="color: #1a1a18; display: block; font-family: 'Myriad Pro'; font-size: 9.5px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">Students should appreciate the variety of sometimes conflicting arguments surrounding this issue. Note the complexity of the problem and the uncertainty of global climate models. Students should be aware of the concept of global dimming due to increased levels of atmospheric pollution. <span style="direction: ltr; display: block; margin-bottom: 0pt; margin-left: 0.38in; margin-top: 6.48pt; text-align: left; text-indent: -0.38in; unicode-bidi: embed;">__**ESSAY - homework**____ **Outline the arguments surrounding global warming** __Your essay should include discussion of the following bullet points, also include a bibliography and only use wikipedia as a starting point for further reading - do not copy and paste! Make this at least 600 words. • Global dimming (p154)drop in temperature was a 2-3% reduction from 1969 to 1990 - it may be masking the full increase in global warming • Uncertainty of global climate models • Earth’s rotational wobble • sunspot activity • Is it possible that increased temperature is causing an increase in greenhouse gases and not the other way around? ** 6.1.7 Evaluate contrasting human perceptions of the issue of global warming **. [] <span style="color: #1a1a18; display: block; font-family: 'Myriad Pro'; font-size: 9.5px; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal; margin: 0px; text-align: left;">Students should explore different viewpoints in relation to their own. media type="custom" key="8487864"

__** Limestone Investigation, to demonstrate some chemical reactions which lead to Carbon dioxide emissions **__ Did you know 5% Of global carbon emissions are due to the production of cement?

Limestone is a ……………………………….. rock. It was formed from …………………………………………….. ……………………………………………………………………………………………………………………………………………………………. Its chemical name is ………………………….. ………………………………… (CaCO3). Chalk is another example of this compound and ……………………………….. is the metamorphic version. 1. Collect a piece of limestone and look at it carefully. Record your observations: 2. Put the limestone on the corner of the wire gauze, as you were shown and heat the chip strongly in the hottest part of the Bunsen flame for about 10 minutes. 3. Turn off the Bunsen. Look at the chip again but do not touch it. Record your observations again. 4. When it has cooled, put the chip into a test tube. Hold the test tube in your hand and add water, **a drop at a time**, from a wash bottle (6 drops max). Record your observations: 5. Add more water until the tube is about half full, put a bung in the tube, and shake to thoroughly mix. Filter the mixture into a boiling tube, to separate the solid from the solution. 6. Use a glass rod to extract one drop of the filtrate and test its pH using universal indicator paper. Record your result here: 7. Use a clean straw to gently blow through the filtrate and record what happens,
 * Copy and complete the following **
 * Carry out the steps below **
 * What do you think you have made?**