My son was watching some scientific videos on YouTube when he came across a story on climate change. As a skeptic, I told him why I believe the theory is flawed, though I did tell him it is probably best not to argue the point with teachers, since skeptics tend to get labelled as "anti-science deniers", and I also urged him to look at the science and decide for himself, though I would be happy to help him evaluate various arguments.
However, this particular video, though adopting a (mostly) objective tone -- excepting a few claims about the current cabinet being filled with "anti-science deniers" and oil executives* -- puzzled me with one claim. Among various figures -- invariably the most extreme examples possible -- there was a claim that CO2 levels had risen 450 ppm in the last century. Now, as far as I know, CO2 generally hovers around the 350-450 ppm level more or less (I may be going too far one either end, actually, but it usually falls in that range). So, if this claim is correct, at the start of the First World War there was no atmospheric CO2?
This is a bit baffling, as I seem to recall trees existing in the period, not to mention that without CO2, the temperature of Earth would likely be slightly below freezing, which I think they would have noticed. I know there was a very cold period in the 19th century, but I did not think it was quite that cold, not to mention that I think someone might have noticed the lack of vegetation.
Obviously, the person making this video simply has no idea of what he speaks, and picked up a number either from someone equally ignorant, or copied a number incorrectly. But that points out a problem not just with YouTube, but with popular science reporting as well. They simply parrot numbers and claims without any evaluation. 97% of scientists, 7 inches of sea rise, x degrees in the past century and so on... They do not bother checking if the numbers even make sense. They have such faith in their beliefs they simply parrot them. And, sadly, many readers and listeners just accept them. No mention of all the skeptics who had argued against these theories, the many petitions signed by equally large numbers of scientists, and the many problems trying to make these models match reality. No discussion of the secretiveness about how the "hockey stick" was generated, or that it omits the Medieval Warm Period or Little Ice Age. No mention of the earlier panic over global cooling. Or the many who pretend that panic never happened.
Until we get some better reporting, I am afraid real debate over AGW will not exist and we will simply have this foolish close minded situation where any skeptic is dismissed as anti-science.
One thing I never quite figured out. Historically, CO2 drops during ice ages, and rises afterward, however, overall, each ice age seems to generally deplete CO2 somewhat. That is why some few scientists argue we need to increase CO2, as the next ice age could drop levels below that needed for vegetation. But, ignoring that, what I cannot figure out is that, historically, CO2 has been very much higher, as high as 2200 ppm in the Ordovician. Yet the globe did not boil over as many AGW models predict at MUCH lower concentrations. How do AGW proponents explain the lack of global meltdown in thee past eras?