Summer heat wave, or global warming?

In the past, most weather experts hesitated to blame short-term weather events -- say, a terrible winter storm or a nasty heat wave -- on longer-scale climate shifts like global warming.

But this week -- as many Bay Area residents flee to air-conditioned theaters to watch Al Gore's global warming film, "An Inconvenient Truth" -- the latest sweltering weather is starting to look to many like a calling card of global warming.