The producers of An Inconvenient Truth have offered to supply American classrooms with 50,000 copies of the movie free of charge. That offer has been rejected by the National Science Teachers Association (NSTA), the nation's leading science education teachers group, citing a risk to funding from key financial supporters.

One of those supporters is Exxon-Mobil.

The news was buried deep in the Washington Post website and reported by Laurie David, a producer of the film and founder of StopGlobalWarming.org

In their e-mail rejection, they (NSTA) expressed concern that other "special interests" might ask to distribute materials, too; they said they didn't want to offer "political" endorsement of the film; and they saw "little, if any, benefit to NSTA or its members" in accepting the free DVDs.

Gore, however, is not running for office, and the film's theatrical run is long since over. As for classroom benefits, the movie has been enthusiastically endorsed by leading climate scientists worldwide, and is required viewing for all students in Norway and Sweden.

Still, maybe the NSTA just being extra cautious. But there was one more curious argument in the e-mail: Accepting the DVDs, they wrote, would place "unnecessary risk upon the [NSTA] capital campaign, especially certain targeted supporters." One of those supporters, it turns out, is the Exxon Mobil Corp.

Oil industry supporters will be quick to endorse the decision, agreeing that An Inconvenient Truth does indeed represent a special interest. What they will conveniently ignore is that unlike industry friendly messages pushed into the curriculum, An Inconvenient Truth is based on, and endorsed by, objective science - the very subject the National Science Teachers Association says it promotes.

What truth is more inconvenient? It depends where your pay cheque comes from.