They are really different then most kinds<span />
It will get lower since the pressure around the barometer gets lower
The answer is: the source of information could be biased
The scientist is interviewing environmentalists and then generalized their opinion as "people". An environmentalist is a person that cares about the environment, so they will more likely to deny the option that harms the environment. If the dam harmful to the environment, most environmentalists will not approve it.