One of climate “skeptics'” favourite argument which I myself have had to deal with is that “warming has stopped since year x” or to take a snowy winter or cool summer as “proof” that warming is not happening. What these people misunderstand – or consciously ignore – is that weather is not climate. The term “climate” refers to the long-term average over at least 30 years. So “climate” denotes the long-term trend whereas “weather” denotes short-term variations.
This cute video is a great explanation of the difference between long-term and short-term. “A common mistake when interpreting statistics is to look at them from too short a distance.”