finding reputable sources in the days of youtube

Well I am having a hard time deciding for sure what I am doing. If I stick with the global climate change and the effects on animals my problems will be identifying reputable sources. There is a lot of data out there and much of it is in the form of viral-video so documenting the validity of the source is next to impossible. With so many web sites enabling users to post video and audio from any number of sources, copy-righted or not, how will a researcher prove that the source is real and not a fabrication. Furthermore with the topic being so politically charged I have to be concerned with misinformation clouding the results. As far as printed documents go journals, electronic and other wise, magazines and pamphlets offer me the most how since the printed books on the subject are going to be some what dated and more concerned with the climate changes and less their effects on animals.