You don't have to rely on experts. You can do your own experiments. Try this one. Put on a heavy overcoat and go outside for a walk. Do you notice something? Yes! You feel warmer with the overcoat on, maybe even too warm. Now take it off, notice something else? Yes you're cooler without it on.
For those in the know it's called "insulation", though this may be a new concept for you. "insulation" is something that stops heat escaping from a warm place to a cold place. OK if you can get that concept we can move onto the next stage. Now, some gases in the atmosphere act as insulation for the whole world. If they didn't then the world would freeze over because the sun isn't hot enough to keep things toasty on its own. In the 1800's someone realized this and wondered why the world was warmer than it should be according to the laws of thermodynamics. So he did some experiments and found that some gases in the atmosphere had an insulating effect, they stopped heat getting out into space. One of those gases is carbon dioxide (CO2). Over the last few million years global temperatures have tracked the level of CO2 in the atmosphere. When it's high the world is warm, when it's low it's cold. It's exactly like an overcoat for the whole world (remember that experiment I asked you to do). Right,next stage. When you dig up coal or pump oil and burn it then it makes new CO2 which goes into the atmosphere and makes the world's overcoat thicker. Before the industrial revolution the global level of CO2 was much lower than it is now because we've burnt lots of buried carbon in the last 200 years and it stays in the atmosphere for a long time. That's like putting on two overcoats. See if you can work out what happens, we'll take it slowly. One overcoat keeps you warm when it's cold outside, two overcoats keeps you even warmer. The CO2 is like an overcoat for the whole world, so more CO2 is like having an extra overcoat so the world will be warmer. Simple stuff. If the extra CO2 didn't keep the world warmer then we'd have to re-write the laws of thermodynamics. A famous scientist once said something along the lines of "If your new theory conflicts with Newtonian Mechanics, then tough for Newtonian Mechanics, if your new theory conflicts with Special Relativity then tough for Special Relativity, but if your new theory conflicts with the laws of thermodynamics then you new theory is in deep trouble". That's where the arguments of climate change deniers fall down, they conflict with the laws of thermodynamics, oh and actual observations as well. You need to get your information from sources other than Faux News /Fox Noise, try this http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change . If that's too tough for you then stick to this http://en.wikipedia.org/wiki/Alice%27s_Adventures_in_Wonderland .
