Tony Snow used the term "global warming" in his January 18, 2007 press briefing. But this reference is not found if you use the whitehouse.gov search function (you have to put the term in quotes). The search box is in the upper right corner of the main http://www.whitehouse.gov/ page. Part of the briefing is indexed, since the search turns up "addiction to oil" in the same sentence as "global warming". But it does not find "greenhouse" or "climate change" in that same sentence. However, "climate change" is indexed in many other cases. It is as if someone took "electronic white-out" and made part of a sentence disappear from the search indexing process.
"Global warming" is indexed by the whitehouse.gov search function in one case, a memo that tries to cast doubt on human caused global warming. But, if you compare whitehouse.gov searches with advanced google searches limited to the whitehouse.gov domain, then you can find more examples of these curious omissions of "global warming" from the whitehouse.gov search function.
The phrase "globe is warming" which was used by the President in one briefing is also not indexed by the search function.
The word "plame"and "joe wilson" seems to be uncensored. I guess "global warming" is more sensitive to the White House?