Then outline how your strategies will address them. Listen to him in private. Sometimes all a skeptic needs is proof that he's being listened to. Honor him by listening to his concerns, but do it in private so he has no incentive to perform. Go for the long haul.
Skeptics often wear out their welcome over time as people catch on to their chronic negativity.
If you can avoid getting too defensive and continue to offer solid arguments for your position, the group's opinion is likely to sway in your direction. Follow these strategies and your skeptic should become less of a problem. Or, if these don't seem like offering enough, take a tip from the Korean researchers. Serve up a big offering of peanuts, fruit and cabbage. And don't bother holding the anchovies.