Transcript Chp 16
Chp 16 CLIMATE CHANGE 16.1 What is Climate Change VOCABULARY Climate Change Global Warming Climate change refers to the changes average weather patterns. More or less rain then normal in some areas, more or less wind, hotter or colder temperatures. All of these things are climate change. Global warming on the other hand is the raising of the average temperature on earth by having gases like CO2 absorb heat and trap it like a blanket around the earth. Enhanced Greenhouse Effect Carbon Dioxide Equivalent Carbon sinks Ozone layer Permafrost 16.1 Greenhouse Effect VOCABULARY Climate Change Global Warming The main way that global warming works is though the greenhouse effect. This effect traps heat close to the earth and holds it there by heating up greenhouse gases (GHGs) the same way that the glass in a greenhouse holds heat in. The greenhouse effect is needed on earth, without it the average temperature on earth would be about -18oC. The thing that is dangerous is the enhanced greenhouse effect. This is when the air is heated too much and weird weather starts to happen. Enhanced Greenhouse Effect Carbon Dioxide Equivalent Carbon sinks Ozone layer Permafrost 16.1 What are Greenhouse Gases There are a many GHGs, the main ones are: a. Water vapour b. CO2, carbon dioxide c. CH4, methane (1 ton = 21 tons of CO2) d. N2O, nitrous oxide (very little) e. CFCs, chlorofluorocarbons (1 ton = 10,000 tons CO2) Even though it has the least heating affect CO2 is the worst GHG because there is just so much of it. Anything that produces CO2 is called a carbon source and anything that absorbs CO2 is called a sink. 16.1 Ozone Layer VOCABULARY The ozone layer is another aspect of climate change. It is the layer of ozone gas (O3) in the atmosphere that absorbs cancer causing UV rays. It has thinned out because of the presence of CFCs in the atmosphere. While it is good that it absorbs UV light it is a part of enhanced global warming because it also absorbs a lot of heat further heating the air in the atmosphere. Evidence of climate change includes direct evidence that can be measured and indirect evidence that implies there is a change going on. Climate Change Global Warming Enhanced Greenhouse Effect Carbon Dioxide Equivalent Carbon sinks Ozone layer Permafrost 16.1 Evidence of Climate Change VOCABULARY a. Direct Climate Change i. Atmospheric CO2 levels are rising Global Warming ii. Average global temperature is rising Enhanced Greenhouse iii. Glaciers and Ice sheets that used to last year round are shrinking iv. Permafrost is melting and mudslides are happening. v. Sea levels are rising vi. The sea ice in the arctic is melting Effect Carbon Dioxide Equivalent Carbon sinks Ozone layer Permafrost 16.1 Evidence of Climate Change VOCABULARY a. Indirect Climate Change i. Tree rings Global Warming ii. Ice cores Enhanced Greenhouse iii. Sediments iv. Coral rings Effect Carbon Dioxide Equivalent Carbon sinks Ozone layer Permafrost 16.1 Evidence of Climate Change VOCABULARY While there is not complete agreement among scientists the following things are not disputed: Climate Change Global Warming The Earth is 0.6oC warmer now than it was in 1900. O.51oC of that happened since 1980. Enhanced Greenhouse Human activities do contribute to climate change and global warming. Carbon Dioxide c. GHG emissions likely speed up global warming. Carbon sinks d. Global warming is a problem and we should do something about it. a. b. Effect Equivalent Ozone layer Permafrost 16.2 Influences on Climate Change and Climate VOCABULARY El Nino Thermocline There are two kinds of influences on climate on earth. natural human caused. La Nina 16.2 i. Natural Influences El Nino is when the ocean currents go reversed to what is normal for them. This causes moist wet low pressure zones over South Americas and brings rain while causing drought in Indonesia and North America. It causes our winters to be milder as well. ii. La Nina is the opposite of El Nino. It brings colder and wetter than normal winters. iii. Volcanic Eruptions cause large amounts of SO2 to go into the air. This absorbs heat. The eruption of Mount Pinatubo in 1991 cooled the earth by about 0.8oC for 1 year. VOCABULARY El Nino Thermocline La Nina 16.2 i. ii. Human Influences Combustion of fossil fuels puts carbon that has been stored for millions of years back into the atmosphere. VOCABULARY Deforestation for the sake of agriculture is causing use to lose a major carbon sink. We need to grow our forests faster than we cut them down to absorb CO2. Thermocline iii. Industry releases tones of CO2 every year to make us products to buy. Many power stations also emit CO2 gas. iv. Waste Disposal the rotting or decaying of organic waste releases methane which is a GHG. El Nino La Nina 16.3 Potential Impact of Climate Change 16.3 Impacts of Global Warming Weather Changes Impacts on Forests Impact on Animals Impact on Canada’s Northern Regions Impacts on Human Health Saftey Impacts on Sea Level