If you had told me that I would be entertained by a two-hour powerpoint presentation by Al Gore on global warming, I wouldn’t have believed you. I’m not alone in being weary of this documentary. Certainly there is massive resistance not only from skeptics of the dangers of global warming, but also from the mockers of Al Gore. A recent South Park episode had a Gore caricature repeatedly endangering the lives of the main characters by Chicken Little-ing an imaginary threat called Manbearpig.

On the other side of the spectrum, there are those who see this movie as a campaign commercial for another Gore presidential campaign. That people are more inclined to vote for Gore after seeing the movie is just a side-effect of the movie being so good. Probably for the good of his cause, Gore is not going to run for the presidency any time soon. He said so much in a Talk of the Nation interview, and NPR listeners ought to hold him to it.

An Inconvenient Truth could’ve been a dry recitation of statistics. It could’ve been an alarmist fearfest. It could’ve been Bush-bashing agitprop. It could’ve been a sunny, let’s-all-pitch-in, rose-colored white-wash. Instead — although it is not without humor and Gore-aggrandizement — it is a remarkably sober and fascinating look at the Earth’s climate system and the dangers of interfering with it. The tone of the movie stays even-keeled and even ends on a positive (even optimistic) note.

Regardless of what you think about global warming, you should see this movie. Everyone. Should. See. This. Movie. I’m not advocating that for political reasons — although I think this issue is finally percolating to the top of the political issue pot — but for historical reasons. Just as The Passion of the Christ and Fahrenheit 9/11 in 2004 prefigured the many similar movies that followed them, An Inconvenient Truth is a watershed film. A whole new genre of major political issue movies is going to follow in the wake of this one.

Time will decide whether Gore or the naysayers are right. In the meantime, consider this a preview of a large and worldwide issue battle that will rage in the near future.

RELATED: The AP finds the 19/100 climate scientists who have seen the movie support its claims.

The inconvenient truth about A Prairie Home Companion is that it is lousy. I wanted so much to like it. As I grow older, I find I have the ability to appreciate things I didn’t before. One of those things is music by The Rolling Stones. Another is the stoic Lutheran humor of the “A Prairie Home Companion” radio show. Too little of that humor is on display in Robert Altman’s new film (script credit besmirching the name of host Garrison Keillor). The movie is off-track right at the post-modern set-up — which takes the convention of a backstage musical and layers on an Angel of Death (played with negative charisma by Virginia Madsen), a meddling noir detective (the show’s popular Guy Noir, shoehorned in and made unrecognizable by a pratfalling Kevin Kline) and inserts fake musicians played by movie stars among the real musicians. The result is either awkward screen performances by radiofolk, the caricature-faced Keillor chief among them, or musically suspect performances by screenfolk, smokerlunged Lily Tomlin chief among them.

Altman and Keillor seem to have settled on a theme of mortality, but have little to say on that theme. A character is killed by the angel of death half-way through the movie — but he hasn’t been properly introduced, so we don’t miss him. The one song that should’ve brought the house to tears, “Goodbye to My Mama,” a haunting song when I heard it sung by Meryl Streep on the radio, in this film registers not a sniffle. The movie cuts between the show and nostalgic backstage conversations, occasionally pausing for some self-indulgent antics. People who have never listened to the show (and I’ll admit I’ve never listened to one all the way through) might get the impression that it is all fake commercials and old-time music. The centerpiece of the radio show to me, though, is the velvet-voiced Keillor’s storytime, where he relates the news from a the fictional town of Lake Wobegon, a Saturday Evening Post world where “all the children are above average.” A slow zoom in on Keillor spinning one of these tales would’ve been more magical than any faux-musical performance, and a truer look into the artifice of storytelling and showbusiness.

To top it all off, A Prairie Home Companion, like many Altman films, suffers from an excess of denouement. The Texas axeman sent to kill the show is conveniently dispatched by the angel of death, but the show dies anyway, and the movie keeps going on, and on. Altman and Keillor stoically feign disinterest in death — but the truth is, they don’t know when to give up the ghost. I will say this: the movie, like the show, plays well enough as background noise for an afternoon nap.

RELATED: Elvis Mitchell interviews Altman about Prairie Home