Amidst his various accomplishments as a political figure during his years in the Senate and as Bill Clinton’s Vice President, it may well be that Al Gore’s greatest act of public service will prove to be his prescience in recognizing global warming as perhaps the single most pressing issue of our time and his unflagging efforts to inform people about the dangers it poses to the future of the planet (if not his success in actually doing something about it while in office). This dense but surprisingly sprightly documentary represents an effective part of Gore’s crusade on the subject.

As directed by Davis Guggenheim, “An Inconvenient Truth” has many of the aspects of an especially well-done infomercial. Essentially it’s a record of a lecture that Gore has delivered around the world, marked not only by smooth delivery (compelling even if, as was the case during his political campaigns, his attempts at warmth and humor often seem stilted), but by a panoply of visuals–charts, graphs, cartoons–to bring the points home sharply and persuasively. From a “legal” perspective, Gore presents a strong case, and the director showcases the argument in a way that gives it the greatest possible punch.

The result is a film that fulfills its educational purpose quite convincingly. Its use of the evidence might be questioned, but with this picture Gore certainly throws down the gauntlet to those who contend that the danger of global warming is exaggerated. They have an obligation to respond not with vague generalizations but very specifically to the data Gore lays out here with directness and skill. Because as the former VP underlines, this isn’t an issue we can afford to hide under the carpet, particularly when the present administration has embarked on policies that exacerbate rather than address it. He cogently argues that it’s too important a problem to ignore–one that threatens the well-being of future generations. And as Gore emphasizes, ours has an obligation to confront it.

Well worth seeking out, inviting others to, and debating afterward.