Anyone who can be labeled as a "scientist". Because everybody assumes anyone who takes all the math and science classes needed to be called a scientist must be really smart. So the average person will listen fairly uncritically to anyone called a "scientist" talking about anything, whether it's in the scientist's field or not, because they must know more than the average person.
I think it's reasonable to assume a scientist is smart, but smart doesn't mean knowledgeable or wise. So scientists should be listened to, but critically. And they should get less attention than those with actual experience in the subject under discussion.