GIS provides a graphical output for up to five search terms. Numbers on the graph reflect how many searches have been done for a particular term, relative to the total number of searches done on Google over time. They don't represent absolute search volume numbers, because the data is normalized and presented on a scale from 0-100; each point on the graph is divided by the highest point, or 100.
So away I went, plugging in two terms, global warming; and climate change for parameters, worldwide, and for all recorded time (2004 - present).
Interesting graph (I also chucked in Al Gore). GIS also scales countries of the world. Here's the top ten countries sorted on global warming.
Top regions for global warming Region al gore global warming climate change Indonesia 19 100 25 Philippines 41 77 29 India 18 76 27 South Africa 37 69 43 Australia 47 54 80 United States 100 51 19 New Zealand 38 49 56 Singapore 36 43 29 Canada 63 42 37 Kenya 0 39 100
Still, it's a cool tool.
Global Warning Climate Change Energy