(mt started the John P. Holdren bandwagon before I could write this post but I'm going to pile on..)
I first saw John P. Holdren speak at the Chicago Humanities Festival last year. I was very impressed by his savvy, big-picture take on the whole climate-energy problem. In particular, I like the phrase he is advocating: "climate disruption".
I'm not sure of the origins of "Global Warming" but it was in common usage among scientists when I entered the field in the early 90's. As Holdren said, "warming" sounds almost benign; like a balmy day on the beach. The big problem with this phrase is that it implies that it's all about temperature. Precipitation is actually a bigger thing to worry about. It also implies that its uniform ("global") when there will be large regional differences in response and only a warming in the global-average sense. The global average temperature is a good index for scientists to talk about with each other but not much good for policy planning.
(this paragraph corrected as suggested by the comments.)
"Climate change" is a phrase popularized by Republican pollster Frank Luntz who advised the Bush administration and Republicans everywhere to use it instead of "global warming". This phrase is incredibly wishy-washy: Its "change": Maybe up, maybe down, maybe no big deal! Personally, I've managed to make it an exact simile for "global warming" and so will sometimes use it but it should really be avoided by scientists when talking to the public.
Now "climate disruption" is much better. The general pattern of climate where you live, the extremes and patterns of precipitation, clouds, snowfall, storms and temperature, are going to be disrupted from their normal patterns. "Disruption" is an edgy, angry word that gets your attention. Its probably not benign. Let's all try to use it.
Another good phrasing that Holdren uses is our three options for dealing with climate disruption: adaptation, mitigation and suffering. We are already doing some of each and what's up for grabs is the future mix.
You can find video of Holdren's talk at the John F. Kennedy Jr. Forum and a pdf of his slides here.