You really need to change your screenname. (How can you "connect the dots" if ANY degree of speculation is immediately dismissed?)
I would say that what those posters are suiggesting is more than just a small degree of speculation.
Even you acknowledge that there is speculation in volved in their comments. the use of the words 'possible' and 'should' are admission that the evidence claimed by evironmentalists simply cannot be established right now and may never be established. That clearly falls within the context of speculation, doesn't it? To say otherwise is being intellectually dishonest.