Global warming
- 1. GLOBAL WARMING PREPARED BY ANJU A KEYI SAHIB TRAINING COLLEGE
- 3. Global warming, the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries. Climate scientists have since the mid-20th century gathered detailed observations of various weather phenomena (such as temperatures, precipitation, and storms) and of related influences on climate (such as ocean currents and the atmosphere’s chemical composition). These data indicate that Earth’s climate has changed over almost every conceivable timescale since the beginning of geologic time and that the influence of human activities since at least the beginning of the Industrial Revolution has been deeply woven into the very fabric of climate change.
- 4. Almost 100% of the observed temperature increase over the last 50 years has been due to the increase in the atmosphere of greenhouse gas concentrations like water vapour, carbon dioxide (CO2), methane and ozone. Greenhouse gases are those gases that contribute to the greenhouse effect (see below). The largest contributing source of greenhouse gas is the burning of fossil fuels leading to the emission of carbon dioxide. CAUSES OF GLOBAL WARMING
- 6. When sunlight reaches Earth's surface some is absorbed and warms the earth and most of the rest is radiated back to the atmosphere at a longer wavelength than the sun light. Some of these longer wavelengths are absorbed by greenhouse gases in the atmosphere before they are lost to space. The absorption of this long wave radiant energy warms the atmosphere. These greenhouse gases act like a mirror and reflect back to the Earth some of the heat energy which would otherwise be lost to space.
- 7. The reflecting back of heat energy by the atmosphere is called the "greenhouse effect". The major natural greenhouse gases are water vapour, which causes about 36-70% of the greenhouse effect on Earth (not including clouds); carbon dioxide CO2, which causes 9-26%; methane, which causes 4-9%, and ozone, which causes 3-7%. It is not possible to state that a certain gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive. Other greenhouse gases include, but are not limited to, nitrous oxide, sulphur hexafluoride, hydrofluorocarbons, per fluorocarbons and chlorofluorocarbons.
- 8. Global warming causes by greenhouse effect Greenhouse gases in the atmosphere (see above) act like a mirror and reflect back to the Earth a part of the heat radiation, which would otherwise be lost to space. The higher the concentration of green house gases like carbon dioxide in the atmosphere, the more heat energy is being reflected back to the Earth. The emission of carbon dioxide into the environment mainly from burning of fossil fuels (oil, gas, petrol, kerosene, etc.) has been increased dramatically over the past 50 years, see graph below. : Cause for global warming: Carbon dioxide emissions in million tons per year over the last 200 years. (graph taken fromhttp://www.globalwarmingart.com/wiki/Image:Global_Carbo n_Emission_by_Type_png)
- 9. Global warming cause: Concentration of carbon dioxide has dramatically increased in the last 50 years (Source: NOAA)
- 11. From which sectors do the major greenhouse gas emissions come from? The lower part of the picture shows the sources individually for the gases carbon dioxide, methane and nitrous oxide, respectively. (Graph from http://en.wikipedia.org/wiki/I mage:Greenhouse_Gas_by_S ector.png)
- 12. Effects of global warming There are two major effects of global warming: Increase of temperature on the earth by about 3° to 5° C (5.4° to 9° Fahrenheit) by the year 2100. Rise of sea levels by at least 25 meters (82 feet) by the year 2100.
- 13. What are the other effects of global warming?
- 15. Each year, scientists learn more about the consequences of global warming, and many agree that environmental, economic, and health consequences are likely to occur if current trends continue.
- 16. Melting glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and increase the risk of wildfires in the American West.
- 17. Rising sea levels will lead to coastal flooding on the Eastern Seaboard, especially in Florida, and in other areas such as the Gulf of Mexico.
- 18. •Forests, farms, and cities will face troublesome new pests, heat waves, heavy downpours, and increased flooding. All those factors will damage or destroy agriculture and fisheries.
- 19. Disruption of habitats such as coral reefs and Alpine meadows could drive many plant and animal species to extinction.
- 20. How You Can Stop Global Warming
- 21. 1. Speak up! “Talk to your friends and family, and make sure your representatives are making good decisions By voicing your concerns—via social media or, better yet, directly to your elected officials—you send a message that you care about the warming world. Encourage Congress to enact new laws that limit carbon emissions and require polluters to pay for the emissions they produce.
- 22. 2. Power your home with renewable energy. Choose a utility company that generates at least half its power from wind or solar and has been certified by Green-e Energy, an organization that vets renewable energy options. If that isn’t possible for you, take a look at your electric bill; many utilities now list other ways to support renewable sources on their monthly statements and websites.
- 23. 3.Reduce water waste Saving water reduces carbon pollution, too. That's because it takes a lot of energy to pump, heat, and treat your water. So take shorter showers, turn off the tap while brushing your teeth, and switch to WaterSense-labeled fixtures and appliances.
- 24. 4. Buy better bulbs LED light bulbs use up to 80 percent less energy than conventional incandescent. They’re also cheaper in the long run: A 10-watt LED that replaces your traditional 60-watt bulb will save you $125 over the light bulb's life.
- 25. 5. Drive a fuel-efficient vehicle. Gas-smart cars, such as hybrids and fully electric vehicles, save fuel and money. And once all cars and light trucks meet 2025’s clean car standards, which means averaging 54.5 miles per gallon, they’ll be a mainstay.
- 26. 6. Pull the plug(s). Taken together, the outlets in your home are likely powering about 65 different devices – an average load for a home in the U.S. Audio and video devices, cordless vacuums and power tools, and other electronics use energy even when they're not charging. This "idle load" across all U.S. households adds up to the output of 50 large power plants in the U.S. So don't leave fully charged devices plugged into your home's outlets, unplug rarely used devices or plug them into power strips and timers, and adjust your computers and monitors to automatically power down to the lowest power mode when not in use.