The causes of global warming and climate change!

There are two competing theories for the recent global warming trend.

The first is based on a theory which followed the warming trend that occurred between 1975 and 1998.
The second theory is based on highly correlated data going back thousands of years.

Most agree that the temperature has increased about 0.6 - 0.7 Centigrade over the last century and that the level of CO2 or Carbon Dioxide a greenhouse gas has been increased in the atmosphere by 25-30% from pre industrial values.

The first theory, which is the generally accepted one, is that the release of greenhouse gases from the burning of fossil fuel and from land use are responsible for the resent temperature increase.
The second theory is that the sun's magnetic field and the solar wind modulates the amount of high energy cosmic radiation that the earth receives. This in turn affects low altitude cloud cover and how much water vapor there is in the atmosphere and thus regulates the climate.