5 down: Hearse, perhaps, switched jobs, creating greenhouse gases (6, 9)
This example of DA Bullshit is most egregious when one considers how much fun emissions should have entailed. Instead, we get the ridiculous hearse = bone car, so that hearse, perhaps, switched = carbone and jobs = missions, which gives hearse, perhaps, switched jobs = carbon emissions = greenhouse gases.
Update: As the comments say, that should be hearse, perhaps = bone car so that hearse, perhaps, switched = carbone is not so egregious a piece of bullshit. I’m still leaving the clue in DA Bullshit, though, mostly because I don’t want to delete this entry and I don’t know where else to put it.