The problem is rising Co2 due to human activities primarily from burning fossil fuels. A certain level is required to keep the planet from freezing. Too much and it overheats. You only need look at rising Co2 to know were headed for doom both from a climate and an ecological perspective. Historically these levels have fluctuated but have never exceeded 300 ppm over the last 800 thousand years. Since about 1950 we have exceeded that level and are at 400 ppm heading straight up. Besides eventually causing the planet to overheat, the ocean is absorbing this Co2 disturbing it’s temperature regulation. Exactly how the two interact is a difficult modeling process but overall the net result will be a greenhouse runaway problem.
Ecologically, this increase in Co2 is affecting the oceans PH causing many spices to die off. This is happening now. Finally, when it rises enough all the mammals (including us) will die off. The plants will be happy!
I think that YouTube is just click bait.
Edit: Just to be clear, fluctuating temperatures in the atmosphere and oceans are a symptom of rising Co2 levels same as abnormal ice buildups and melts. The problem is Co2 rise not whether the temperature is going straight up right now, but it will eventually.
