You might at least view your own link. He clearly hasn't any depth in his knowledge, or else he is just an actor reading a script. And if you didn't notice the error at 4.21, I suggest you are probably missing a lot from many other articles.
So it isn't surprising that you've missed a lot of other data in your simplistic assertions. For instance, CO2 levels rose 50% from their all time lows of 180ppm 18,000 years ago by the end of the ice age:
Fortunately a completely non-manmade event occurred resulting in higher temperatures, which resulted in increased CO2 levels. From that article you can see that optimum levels for photosynthesis occur at the 500ppm mark.
Yes, I meant "we the planet" rather than we as humans - but the premise still applies - CO2 levels have been a minimum of 20 times hat they are today, and the earth, instead of frying, was abundant with life.