I am actually not sure, usually it is the new members who hand out grey reputation points because they have no reputation themselves. I'd say because you are in the red with your rep at the moment is because it is happening. Join other threads outside of climate change to boost your rep back up. I will give you a free rep to get you out of that hole so your reps might mean something.

Windguy, I have a question: Whenever I give some reputation to someone, to help their reputation out (more green) it only shows as neutral. (grey) Could you explain to me why this is happening? I would greatly appreciate it.