Like Sen. Bernie Sanders (I-VT) on taxes in 2010 and Sen. Ted Cruz (R-TX) on Obamacare in 2013, the Democrats' upcoming talk-a-thon on climate change is precisely not a filibuster. The Senate would not be conducting business overnight, so they're simply availing of unused time to make their voices heard.
They'll wrap up in time for Senate business to begin on Tuesday morning, without an iota of disruption or delay. In fact, Senate Majority Leader Harry Reid (D-NV) is expected to participate in the talk-a-thon. The majority leader controls the floor -- he doesn't need to filibuster to block action.