What is the evidence that the increase in greenhouse gases is primarily caused by human beings?
This link connects to some basic definitions of global warming. The problem is that even definitions of global warming are tied to whether a person is a believer in human caused global warming or a skeptic.
This website lays out some of the basic arguments from a human cause point of view. Unfortunately, it really makes fun of the people who don't believe in the human origins by presenting their arguments as short cliche type statements (in red) and then giving a response (in green) which is much longer. It would be better to see each side of the argument presented at equal length. Also they do not support their green claims with the sources of their evidence.
This site looks at Global warming from a non-human cause point of view.
It uses pejorative type language to ridicule the opposing argument. In this case those who think that global warming has not been caused by human being are being ridiculed. The are called Global warming skeptics. The article looks at the funding of research into GW and suggests that those who oppose anthropogenic warming are not impressed by Obama's spending on research
This site deals a so-called death blow to anthropogenic global warming
The historical argument is being invoked here with graphs and data showing climate change over some hundreds of years. The links suggests that. contrary to those who see the sun having very little role in recent climate change, it has played a key role in the last 800 years or so. The article sees the anthropogenic global warming (AGW)as seriously flawed.
http://www.climatechangefacts.info/#Fact
Just like those who believe in AGW, those who deny it claim to have the facts at their finger tips. They too pepper their discourse with phrases like "it is generally accepted that ...". In fairness, however, this site does go in to far more detail describing both sides of the argument and it also is careful to note all the sources of key information.
Hopefully this website will bring the historical factor into the debate. Often, the current global warming argument tends to just focus on extremely recent history and neglects the reality of enormous climate changes over earths long history. This present a geological and indeed a cosmological scale of 100s of millions of years.
The sun is a key player in the driving on climate change. This website examines this reality and discusses a number for factors related to the sun's variable movement and variable output that serious effects global warming and cooling.
Comics ray are another key driver of global warming. The suggestion here is that cosmic rays from far deep space play a muck larger role in global warming than any man made effects. Of course the level of cosmic rays hitting the earth is supposedly related to the level of the sun's activity and is thus related to the previous point.
The earth's orientation with respect to the sun is also another factor in global warming. It seems that there is a key oscillation that occurs every 100,000 years. These oscillations appear to correspond to the ice ages that the earth has experienced. The orbit of the earth is of course is elliptical and in mathematics this oscillation is referred to as eccentricity.
Another factor is the variation of the tilt of the earth's axis every 41,000 years. This tilt apparently varies between 22° and 24.5°.
A final issue is that the earth also "wobbles" on its axis every 23, 000. All of these associated movements of the earth play a big part in climate change.
