There is a misconception that those people who don’t accept the greenhouse effect as being “the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface” simply don’t understand the physics. Though some people honestly don’t understand the science explaining why carbon dioxide acts as a thermal barrier, many others do — and blindly persist in denying global warming, despite the fact that CO2 levels are undeniably increasing. Why? Because they’re scared witless. Indeed, one would have to be a fool not to be frightened of mankind’s uncertain future because of the ongoing amplification of the greenhouse effect by our burning of fossil fuels.
To understand the greenhouse effect, global warming and climate change, read: