In last year’s much-ballyhooed documentary “An Inconvenient Truth,” Vice President Gore referred at one point to an old science experiment to make a point about global warming: If a frog jumps into a pot of boiling water, it will recognize it’s in trouble and jump out. But if that frog jumps into a pot of lukewarm water that is slowly being brought to a boil, it will remain there, “until, until —” Mr. Gore paused for a moment — “it’s rescued.”

The unlikely analogy elicited a laugh from Mr. Gore’s audience. Of course, it also allowed him to dosey-do right past the prospect that the frog might not make it out of its predicament alive.

The new imperiled-earth documentary “The 11th Hour” has several things in common with “An Inconvenient Truth,” but that particular dance step is not one of them. This film, narrated and coproduced by another well-known personality, Leonardo DiCaprio, isn’t afraid to contemplate the extinction of the human species. It pretty much takes it for granted. “The environment is going to survive. We’re the ones that aren’t going to survive,” as one of the 50 or so environmental experts interviewed in the film points out. And when you consider how briefly the human candle has burnt in the 4 billion-year history of life on earth, that notion doesn’t seem so far-fetched. In all likelihood, as the prominent geneticist David Suzuki suggests in the film, it won’t be long before our species goes the way 99.9999% of them have gone.

The question then becomes: How much of Earth will go down with us? On this planet, which data show to be on slow boil, 50,000 species disappear every year. Extinction and climate shifts have always played a role in nature, but overwhelming evidence — which the film briskly summarizes — shows that the human impact on the environment is responsible for the recent acceleration of both.

“The 11th Hour” is a summer release with a genuine sense of urgency; compared with mankind in the global-warming era, put-upon action heroes like Jason Bourne have got all the time in the world. You could complain that between all the self-assured talking heads and staccato montages of floods and hurricanes and tumbling walls of ice, directors Leila Conners Petersen and Nadia Conners don’t leave much room for debate on the global-warming issue. And you’d be right. The film’s enormous cast of experts reinforces the point that, within the scientific community, that debate had its moment. And now it’s extinct.

That’s not to say that every expert opinion here makes sense. One interviewee proposes Mother Nature’s rights be enshrined in the constitution. A link between toxic air and the uptick in asthma diagnoses seems more than likely, but connecting pollution to behavioral problems such as attention deficit disorder requires a bit more of an argument than the one offered here.

In its haste to dismay the viewer before whisking him out the door to take immediate action, “The 11th Hour” makes the odd misstep. It makes sense to focus on the irony behind Mr. Suzuki’s observation that “the human brain invented the concept of the future,” but that’s no reason to zoom through that fact’s more hopeful implications. Meanwhile, computer renderings of sustainable architectural designs — especially significant, considering that buildings are responsible for one-third of all energy use — don’t stay on-screen long enough to really register.

But the primary objective of “The 11th Hour” is to motivate, and Mr. DiCaprio’s pet project (he appears on-screen every 15 minutes or so) has the rhetorical breadth and succinct editing of the best issue-based documentaries. The deep lineup of interviewees — which includes authors, scientists, former CIA director James Woolsey, and Mikhail Gorbachev — is duly impressive. The tone of enlightened certainty is remarkably consistent.

Less a tutorial than an impassioned plea for action, “The 11th Hour” is also a more efficient use of filmmaking energies than “An Inconvenient Truth” because it doesn’t double as a vehicle for its creator. Late in the film, citing “the great rupture” that took place between man and nature in the industrial age, the film expands into a familiar critique of the way we live today. But anyone who agrees with the closing words in “The 11th Hour” will recognize that critique as a necessary one. “The Earth has all the time in the world — and we don’t.”