1. 1. Global warming is occurring, and humans are contributing to this, agree major scientific agencies, such as NASA and NOAA.


2. 2.  2000 to 2010 was the warmest decade on record, according to the National Oceanic and Atmospheric Administration (NOAA), and 2010 & 2005 were the warmest years on record.
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4. 3.  two-degree increase in temperature has been documented in the US over the last 50 years and precipitation has increased by five percent, says the US Global Change Research Program. This may be due to global warming.
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6. 4.  Sea levels rose around seven inches in the last 100 years. This is the most noticeable change in the past 2,000 years. Global warming causes sea levels to rise and can put countries in danger of flooding and disappearing.
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8. 5. Greenland lost 150 to 250 cubic kilometers of ice per year between 2002 and 2006, while Antarctica lost about 152 cubic kilometers of ice between 2002 and 2005 according to data from NASA's Gravity Recovery and Climate Experiment. This melting of glaciers is caused by the increase in temperatures attributed to global warming.
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10. 6. The frequency of extreme weather events such as wildfires, heat waves, and strong tropical storms is increasing, a phenomenon attributed in part to global warming by some experts.
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12. 7.  Carbon dioxide levels in the atmosphere are higher than they have been for 800,000 years, according to ice core measurements.
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14. 8.  High levels of greenhouse gases released into the atmosphere accelerate global warming. Humans and animals are able to live on Earth's surface due to these greenhouse gases keeping heat close to the Earth's surface, but when the delicate balance is upset, it can have grave consequences on the world's climate.
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16. 9.  Carbon Dioxide is one of the most prevalent greenhouse gases that's causing global warming, and is produced mostly by the burning fossil fuels. Methane and Nitrous Oxide are other examples.
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18. 10. The US emits approximately 6 billion tons of Carbon Dioxide every year. CO₂ is a greenhouse gas that helps increase global warming, and 40 percent of US annual output comes from power plant emissions.
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20. 11. Humans are pouring carbon dioxide into the atmosphere much faster than plants & oceans can absorb it.
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22. 12. Industrialization, pollution, and deforestation have greatly increased atmospheric concentrations of greenhouse gases leading to global warming.
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24. 13. Coral reefs are sensitive to even the smallest changes in water temperature and in 1998 suffered the worst bleaching ever recorded.
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26. 14. The first completely ice-free summer in the arctic region may occur by 2040 or earlier because of the rapid melting of polar ice.
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28. 15. More than a million species face extinction due to the effects of global warming, largely because of disappearing habitats and changing ecosystems.

Sources

http://climate.nasa.gov/
http://www.globalchange.gov/
http://www.ncdc.noaa.gov/cmb-faq/globalwarming.html
http://news.nationalgeographic.com/news/2004/12/1206_041206_global_warming.html
http://www.edf.org/climate/basics-global-warming
http://www.nrdc.org/globalwarming/
http://www.epa.gov/airtrends/aqtrnd95/globwarm.html

http://www.globalgiving.org