2. Global Warming is a Natural Event Some scientists have suggested global warming is due to a natural 1500-year cycle. Climate change is much more likely to be part of a cycle of warming and cooling that has happened regularly every 1500 years for the last million years, authors and scientists Dennis Avery and Fred Singer said.
3. Continental Drift Continental drift is a natural event and it can change the climate. Over a long period of time, places move to colder regions of the globe other move to tropical regions.
4. Earth’s Motions ( Milankovich Cycles ) The earth’s tilt changes 2 degrees. This change affects radiation received at different latitudes. That may make the climate warmer.
5. Solar Activity Sunspots cause the sun to give off more energy. Sunspots are cooler areas of gas on the sun surface, if there are not a lot of sunspots then there will be more heat. When the sunspots explode, they raise the heat. http://www.tilmari.pp.fi/tilmari6.htm
6. Carbon dioxide 100 million years ago there were six times as much carbon dioxide in the atmosphere as there is now. http://www.theforbiddenknowledge.com/hardtruth/global_warming_myths.htm
7. The Video http://www.ossfoundation.us/projects/environment/global-warming/natural-cycle#section-0 This website is talking about how global warming is a natural cycle.
8. Volcanoes Volcanoes throw 30 million tons of carbon dioxide, oceans emit 90 billion tons of CO2 and decaying plants throw 90 billion tons compared to just 6 billion tons of CO2 a year from humans. http://www.life123.com/home-garden/green-living/global-warming/natural-causes-of-global-warming.shtml
9. Temperature Accurate satellite, balloon, and mountain top observations made over the last three decades have not shown any significant change in long-term rate of increase in global temperature. http://en.wikipedia.org/wiki/Temperature_record_of_the_past_1000_years
10. Wobbly Earth Sometime the earth’s rotation is not perfect. Sometimes the earth wobbles, causing its temperature to change. http://www.abc.net.au/science/articles/2000/07/19/153343.htm
11. Methane Methane gas is released by dead plants in arctic tundra and wetlands. Methane is a greenhouse gas that causes the temperature to increase. http://kahnage.wordpress.com/2009/09/16/dead-plant/
12. Water Vapor Water vapor is a greenhouse gas. We have more water than anything on earth. So, more water vapor in the atmosphere will cause the temperature to increase. http://johnstonanalytics.com/--atmosphere