What is global warming? The sun sends out energy as heat and light. This energy comes to our earth during the day time. Some of the sun’s rays get ‘trapped’ in the atmosphere. Some of them get reflected back into space. The ones which get through the atmosphere warm the earth up. All the time, the earth radiates heat into space, which cools it down. We only really notice this at night, when there is no heating from the sun. Some of the heat going out is trapped by the atmosphere. This is what makes our planet warm enough to live on. But if too much heat is trapped, our planet will warm up and the climate will change. What is the atmosphere and why does it trap heat? The atmosphere is the air around the surface of the earth. It is made from a mixture of gases. We need it for animals and plants to survive. Some of the gases act like a blanket, trapping heat. These gases are called ‘greenhouse gases’. This is known as the ‘Natural Greenhouse Effect’. Without it, the earth would be much colder. (the atmosphere is really much thinner than it looks above) So why is global warming happening? Some things that people do are increasing the amounts of the greenhouse gases in the atmosphere, so more heat is trapped. The heating of the earth through human activities is called the ‘Enhanced Greenhouse Effect’ and this is causing the earth to heat up, or global warming. Global warming doesn’t just mean that the earth gets hotter, it means that the whole climate is changing. GLOBAL WARMING IS the consequence of THE GREENHOUSE EFFECT So what is a greenhouse? How does it work? What has this got to do with global warming then?? Think about the greenhouse as if it was the planet and this is…. Explanation of the causes of global warming Human activity is adding more gases to the naturally occurring layer of greenhouse gases. This thickens it so it cannot let as much heat return to space and so the temperature of the earth gradually increases…… GLOBAL WARMING! Name of gas Contribution Source(s) Carbon dioxide (CO2) 50% From burning coal and oil, and the removal of vegetation Chlorofluorocarbons (CFCs) 20% From air conditioners, refrigerators and aerosols Methane (CH4) 16% From rice growing, animal waste, swamps and landfills Ozone (O3) 8% From air pollution Nitrous oxide (N2O) 6% From fertilizers and burning of coal and oil Name of gas Contri Source(s) bution Carbon dioxide (CO2) 50% From burning coal and oil, and the removal of vegetation Chlorofluorocarbons (CFCs) 20% From air conditioners, refrigerators and aerosols Methane (CH4) 16% From rice growing, animal waste, swamps and landfills Ozone (O3) 8% From air pollution Nitrous oxide (N2O) 6% From fertilizers and burning of coal and oil Example of the Greenhouse Effect The Sun’s energy passes through the car’s windshield. This energy (heat) is trapped inside the car and cannot pass back through the windshield, causing the inside of the car to warm up. What’s the difference between “global warming” and “climate change”? Difference GLOBAL WARMING is the increase of the Earth’s average surface temperature due to a build-up of greenhouse gases in the atmosphere. CLIMATE CHANGE is a broader term that refers to long-term changes in climate, including average temperature and precipitation. Effects of Global Warming Rising Sea Level Increased Temperature Habitat Damage and Species Affected Changes in Water Supply The greenhouse effect and global warming! What’s the proof that global warming is taking place? Portage Glacier • Alaska 1914 Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org 2004 Colorado River • Arizona June 2002 Dec 2003 Global warming causes the polar ice sheets melt. It increases the sea-level. It will possibly rise 18 cm by 2030 and 58 cm by 2090. Flooding will probably occur in lowlands. Many cities along the coast may be under sea water. Climate change The Earth is heating up. This will cause glaciers to melt and sea levels will rise. The loss of polar ice will have a profound effect on nature in particular animal habitats. Many of the world’s islands are already disappearing beneath the sea. The tiny island nation of the Maldives is in trouble. If global warming continues, say scientists, the country could sink beneath the ocean within 100 years. The average height of the islands above sea level is 1.5 metres and the rate of sea level rise is currently 59cm per century. Why is global warming happening? Burning of Fossil Fuels Pollution from coal, natural gas, and oil How Global Warming Works Carbon Dioxide (CO2) Fossil fuels (coal, oil, natural gas) When did global warming start? Effects: • Flooding • Extreme Weather • Climate change • And more!!!!!!!! Global Atmospheric Concentration of CO2 How is global warming measured? 1000 Years of CO2 and Global Warming Temperature (Northern Hemisphere) Year Year 2000 1800 1600 1400 1200 1000 2000 1800 1600 1400 1200 1000 Parts Per Million Degree Celsius Increase CO2 Concentrations Billions of Metric Tons Carbon Goal: Reductions in 2007 CO2 Per Year of Metric Billions Carbon Tons Carbon Gigaton Our Goal 2007 Reductions in CO2 Per Year Produce electricity efficiently Use electricity efficiently Vehicle efficiency Solar and Wind Power Biofuels Carbon capture and storage What’s being done now to reduce our emissions? Wind Power Solar Power Fuel-Efficiency What can you do to help solve the problem? Use less: Or use energy saving light bulbs….. Which will also save you money! Simple Things To Do Turn off your computer or the TV when you’re not using it. Take shorter showers. Heating water uses energy. Keep rooms cool by closing the blinds, shades, or curtains. Turn off the lights when you leave a room. Use compact fluorescent bulbs. Or try and generate electricity in a cleaner, more environmentally friendly way? Be Bulb Smart—Use CFLs Incandescent What’s the difference? Compact Fluorescent 500 lbs. of coal •1,430 lbs. CO2 pollution avoided •$30 saved Simple Things To Do . Offer to help your parents keep the air filters on your AC and furnace clean. Walk short distances instead of asking for a ride in the car. Plant a tree. Recycle. Basically you need to reduce your….. All – to recognise that humans have an impact on the environment. Most – describe the impact of deforestation and burning of fossil fuels. Some – know what the Kyoto agreement is. Kyoto agreement • Written in Kyoto, Japan on 11th December 1997! • Came into force on February 16th 2005 • Many countries signed it and said they would try and reduce greenhouse gases being produced!