If you know anyone skeptical of global climate change or someone hesitant to take action in case it is happening, have them watch this: Greg Craven's presentation.

He does not try to convince anyone whether or not climate change is happening. Instead, he tries to convey that we need to decide what do in case it is, in a sense of risk management. What's the larger risk, acting when we don't need to, or not acting when there turns out to be a problem?

He has an effective presentation in both videos; the second one is a little more refined than the first. Watch both. If you agree, spread the word.