Supermarket magnate Ron Burkle recently valued Al Gore's Current TV at $2 billion, the New York Times reports. You'd think that Burkle, one of Current's backers, would know when the produce is not quite ripe. By contrast, NBC Universal recently purchased the nine-year-old Oxygen Network for $925 million. Note that ComScore reports Current's site as averaging only 152,000 unique visitors a month. Sure, we should probably expect this kind of thing after Microsoft set Facebook's value at $15 billion. But still. I know the guy won a Nobel Prize and all. But anybody else starting to doubt global warming?