Recently came a cross a good, unbiased article on global warming in the New scientist. My gut instinct tells me there are many ignorant people scaremongering but I like to see what a proper rational scientific argument puts forward.
"The concentration of CO2 in the atmosphere now stands at around 375 parts per million. A doubling of CO2 from pre-industrial levels of 280 parts per million, which could happen as early as 2050, will add only about 1 °C to average global temperatures, other things being equal. But if there's one thing we can count on, it is that other things will not be equal; some important things will change."
"Water vapour is responsible for a bigger slice of today's greenhouse effect than any other gas, including CO2, any change in the amount of moisture in the atmosphere is critical. A warmer world will evaporate more water from the oceans, giving an extra push to warming. But there is a complication. Some of the water vapour will turn to cloud, and the net effect of cloudier skies on heat coming in and going out is far from clear. Clouds reflect energy from the sun back into space, but they also trap heat radiated from the surface, especially at night. Whether warming or cooling predominates depends on the type and height of clouds. The IPCC calculates that the combined effect of extra water vapour and clouds will increase warming, but accepts that clouds are the biggest source of uncertainty in the models."