| Timmah! said: Just another point of view... For the record, I believe in global warming- average temperatures have been climbing and there's not much debate to be had about that. I simply don't believe that humans are the main cause of it. I believe the most overlooked possible cause for global warming is also the most obvious. Our sun is the heat source for our planet, and thus should be the first thing we look at when heat levels rise. Compare the two graphs below, the first is the global temperature graphed from 1880 to 2004. http://www.earth-policy.org/Indicators/Temp/TempSmall.gif The second is a graph of solar activity from the 1400s to present times. (Data obviously extrapolated back using chemical evidence left behind by solar activity) http://en.wikipedia.org/wiki/Image:Solar_Activity_Proxies.png |
| Timmah! said: To further back up this point, Neptune's largest moon has shown signs of warming since it was last visited by the voyager space probe in 1989. This shows the possibility that warming could be caused by something outside of our closed-planet system (that something being the sun). This is an article from MIT about the warming trend on Neptune's largest moon, Triton. http://web.mit.edu/newsoffice/1998/triton.html In addition to this, Mars has also been warming. This clearly shows that something more than CO2 emissions is to blame for global warming. This is an article from National Geographic about the warming on Mars. http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html |
There are a lot of factors behind these changes, mainly inner ones. Some planets like Uranus have cooled: http://www.boulder.swri.edu/~layoung/eprint/ur149/Young2001Uranus.pdf
| Timmah! said: Another point about 'Greenhouse gasses: The way the operate is that they reflect heat- this reflection works both ways, reflecting heat that is inside the earth's atmosphere back to the earth and reflecting the same amount of heat back into space before it ever reaches the atmosphere. This would result in smaller temperature differences between day and night, not necessarily greater high temperatures. A perfect example of this is a cloudy 24-48 hour period. This almost always results in a cooler day and a warmer night, no change in the 'average' for that period of time. |
You have understood the greenhouse pheonmenon incorrectly. Greenhouse gases like water vapour (non-cloud) and CO2 absorb the heat, they don't reflect it. Clouds do reflect heat, but that's not the greenhouse effect, that's simply the reflecting effect that free H2O doesn't have. Clouds actually have a strong cooling effect because they reflect radiation back to space before it hits the ground.
