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Global Warming Continued. Is it a problem? What are the potential effects?. Earth’s temperature history. The Earth’s climate is in continual flux. Earth’s temperature over the past 425,000 years . Thought questions. If the Earth was warmer in the past, why are people so worried?
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Global Warming Continued Is it a problem? What are the potential effects?
Thought questions • If the Earth was warmer in the past, why are people so worried? • Is a few degrees really worth getting concerned about? • What do you think?
http://www.youtube.com/watch?v=oJAbATJCugs • http://www.youtube.com/watch?v=S95qI2yIEJA
What are the potential effects of global warming? Some we are are already witnessing. Some are predicted from climate models.
1. More droughts – the percentage of land struck by droughts has doubled since 1970
3. More floods – national annual precipitation has increased between 5 to 10 percent since the early 20th century
5. Sea level rise – most recent measurements say up to a meter this century; from thermal expansion and melting ice
1 m 2 m 4 m 6 m
6. Destruction of ecosystems ice floes too far apart drowning polar bears warming seas death of coral reefs
6. Spread of disease -warmer temperatures enlarge the geographic range in which disease carrying animals, insects, and germs can spread -for example, mosquitoes carrying dengue fever used to dwell at elevations no higher than 3,300 feet, but because of warmer temperatures they have recently been detected at 7,200 feet in Colombia’s Andes Mountains -West Nile Virus in the US
7. Social consequences • economic damage from increased severe weather • war and conflict due to drought (limited water and food resources)
What are some of the things you can do about global warming? • Buy cars with low gas mileage. • Carpool or take the bus if possible. • Insulate your house properly for winter (for example, you can buy sheets to put over your windows to limit cold air coming in)…this reduces your energy usage AND saves you money. • Replace old, worn-out appliances. • Turn off lights, computers, etc. when they are not being used. • Recycle. • Turn down the thermostat by a degree in winter and up a degree in summer. • Use energy efficient light bulbs.
Does what you do really matter? • If everyone in the US were to follow the guidelines I just mentioned, it is estimated that the US’s carbon dioxide emission could decrease by 25%.
What can the government do about global warming? • Legislation (for example, limiting greenhouse gas emissions by companies, or incentives for people buying cars with a lower gas mileage). • Supporting research into alternative energy sources!
Questions you should be able to answer. • Is the Earth’s temperature warmer than it has been in the past 400,000 years? • Is the amount of carbon dioxide in the Earth’s atmosphere greater than it has been in the past 400,000 years? • What are some of the potential effects of global warming?