by Laurie David and Gene Karpinski

This past week, NBC completed its Green Is Universal campaign -- a week-long effort to educate and engage the public by infusing its programming with environmental themes. The effort resulted in everything from Matt Lauer reporting from the Arctic circle to Al Gore making a cameo appearance on 30 Rock parodying himself. Throughout the week, global warming was front and center. And then there was Tim Russert.

As the network's Washington Bureau Chief, Mr. Russert was surely alerted to the broadly publicized campaign. The emerald green tie he donned in Sunday's Meet the Press interview with Senator Barack Obama would seem to confirm that. But if you watched the interview, you probably noticed that Tim Russert didn't actually get the memo. Instead, Russert continued his long-running pattern of ignoring an issue that the American voters, the international community and the world's scientists have all identified as one of our most pressing challenges. Not to mention one of the most consequential.

How bad have Tim's interviews been? Over the past ten months, presidential candidates have made 16 appearances on Meet the Press. In the nearly three hundred questions he has asked the candidates, not once has he uttered the words "global warming." Not once.

At the two debates Mr. Russert has moderated, he has found time to discuss a national smoking ban, the drinking age, Bible verses, baseball, and even UFOs but not once did he ask how candidates would address the climate crisis.

His lack of coverage of the issue has been so glaring that one can only wonder whether he still needs to be convinced that global warming is a problem.

Of course, this failure is not his alone, but he is certainly the worst and most prominent example of it.

As a result, it is not surprising that the majority of the Republican candidates have coasted through the primary without having to outline any specific policies to address global warming. And while most of the Democrats have detailed plans, there has been little effort to compare their policies and gauge who is best prepared to tackle this historic challenge.

So here we are at the tail-end of an unprecedented year-long primary campaign and the media has largely failed to ask difficult and direct questions about one of the greatest challenges humanity has ever faced.

In light of this failure, several groups have partnered with Grist [1]to host a presidential forum -- Global Warming & America's Energy Future [2] -- this Saturday in Los Angeles. This will be the first event exclusively devoted to questioning the candidates on their policies and vision for tackling our growing energy problems. But with dozens more candidate forums, debates and interviews, the real question is this:

As interesting as it is to ponder whether we are alone in the universe, when on Earth will Mr. Russert cover global warming as a political issue?

Laurie David is a global warming activist and a producer of the Oscar winning documentary "An Inconvenient Truth". She is also the co-author of a new book "Down-to-Earth Guide to Global Warming [3]" by Scholastic Press. Gene Karpinski is the President of the League of Conservation Voters [4], the independent political voice of the environmental movement.
Copyright © 2007 HuffingtonPost.com, Inc.