Well, they could seek out people with opposing beliefs. Ask them to poke holes in the statement from the first source. If the result isn't convincing, that helps validate the first source. If the answer IS convincing, go back to the first source and ask them to defend their statements and poke holes in the objections of the denier.
Pretty soon, the guy with weak arguments starts to hem and haw, and call you an idiot. Then you know who's lying. You don't even have to understand the science to have a working bull$hit gauge. People ask me why I don't believe in AGW, and I do have scientific objections, but mostly my skepticism is based on the behavior of the believers. If they're acting like liars act, there's a pretty good chance they're liars.
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If it quacks....
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This is what would happen if the reporter was objective.
However, since the media hacks went to liberal journalism schools and were taught by leftist professors, the answers from leftist glo-bull warming scientists fit the template they've been taught to accept.
It's kind of like carbon monoxide. A molecule of carbon monoxide fits a molecule of hemoglobin better than a molecule of oxygen. So the body accepts the carbon monoxide more readily than oxygen and kills itself unknowingly.
Leftists automatically accept leftist ideas without thinking and that will eventually kill us all.
It's time to purge the schools.
Surveys of journalism students consistently show that the most common motivator for the student to enter the field is “to change the world.” Accurately reporting events is far down on the list.