A climate scientist, a politician, and a fifth grader are asked to get the temperature of a glass of water.
The politician consults his richest campaign donors and reports their preferred (most profitable) choice. In a pinch, he'll even poll the audience for the answer.
The climate scientist takes a hundred readings of the air above and around the cup, enters them into a dozen computer models, then reports the average of those results.
The fifth grader sticks the thermometer into the water, gives it a stir, and reads off the number.
Sadly, this joke is not as far from the truth as it should be.
Hundreds of years of weather data has given us unprecedented accuracy at predicting storms and deciding between shorts and jackets, but the idea that it is even remotely useful at determining if or how much heat is being trapped (by greenhouse gasses) has as much value as measuring the air above and around a cup.
If there was evidence of heat being trapped by the atmosphere, it won't be found in the 14 pounds per square inch of rapidly churning air above the ground, but in the first 14-100 pounds per square inch of the ground beneath it (where nobody is looking for it).
When you want to know if the water in the cup is getting hotter or cooling off, you don't ask a politician or measure the air above the cup...
This is not to say that climate science is not a legitimate science, it just that its predictive value doesn't extend much beyond a choice between shorts and jackets.
Take a breath, calm your fears, the world will not be ending tomorrow, even though All Gore won a Nobel Prize for predicting it would nearly a decade ago.