SAN FRANCISCO – In his movie, An Inconvenient Truth, Al Gore connects a series of dots leading to the heartbreaking conclusion that our delicate and beautiful blue marble of an Earth is in deep trouble, and that we are to blame. The problem is that not all Mr. Gore’s dots are related to one another, and the film conveniently leaves many out.

Audiences may be comfortable with this approach, common with dramatic films. But when the subject is science and not simply entertainment, that could lead to serious misunderstandings.

Consider the approach of An Inconvenient Truth to climate change. In the early going, Mr. Gore tells the story of a favorite college professor who studied atmospheric CO2 levels, and presented some of this data to the class while the project was in its early days. Gore says dramatically that they could “see exactly where it was going after the first few years of data.” He contrasts this with the story of a grade-school teacher who brushed off a student who pointed out that the western coast of South America looked like it would fit into the eastern coast of the African continent.

The message here is clear. Making rather swift conclusions based on how things look, leads to the right answers. On the other hand, patient waiting for scientific proof does not. This is a satisfying approach for a non-technical audience because it puts all in a position to evaluate complicated global feedback mechanisms. But drawing conclusions about climate change from a few years of data or just the way things look, is neither possible, nor scientifically valid.

Even more problematic is drawing conclusions about climate change from two photographs, or two lines of data that seem to be doing the same thing. Far more tenuous still is drawing a line from, for example, the Hurricane Katrina disaster to net CO2 emissions.

The latest study from the National Center for Atmospheric Research (NCAR) concluded that global warming, over the long term, will raise the baseline of hurricane activity. However, they also estimated that just over half of 2005’s elevation in sea temperatures compared to the long-term average was due to cyclical climate patterns and natural weather variability.

Drawing a direct line from there to the devastation of Katrina is certainly not, as Mr. Gore would like audiences to believe, making “accurate connections based on sound science.” Yes, there were man-made contributions to the scale of the Katrina disaster, but they were related to overdevelopment and over-engineering of the Mississippi delta far more than to climate change.

An Inconvenient Truth also shows dramatic side-by-side photographs of a once-flowing section of the Colorado River, now a dry river bed, and mentions the influence of irrigated agriculture. This change is a function of agricultural and water policy, and entirely unrelated to global climate change. Gore’s discussion of increased flood damage is also largely unrelated to climate change — some of it is a function of localized weather, but a lot of it is due to human alteration of the natural landscape.

Gore ends his talk with a brief discussion of the real drivers of the many pictures and situations he discussed: population expansion and increased technological capabilities. These are only tangentially related to climate change, if related at all. That is why viewers of An Inconvenient Truth have good reason not to suspend their disbelief, as they do for dramatic fare.

Despite its problems, there is value to Mr. Gore’s project. Within several days, most viewers will likely have retained only some fuzzy memory of the general concepts. This is how it should be, as the finer details presented were riddled with hand-waving and tenuous relationships. But the final message is nonetheless important: those concerned with the impact of their lifestyle on the environment should find ways to make changes in what they are doing and what their community is doing.