The base human mind, the ego, primarily a survival mechanism. is not wired to handle problems of this immense scope. Tribalism is one critical aspect emanating from the base mind, unfortunately it works both for and against these type of challenges.
If humanity were one perfectly aligned tribe — no problem. The reality, however, is that humanity is divided by hundreds of tribes (thus endless war) of various colors, religions, languages, political compartments, and therefore, with the negative offset of the tribal impulse being to fear and hate the “other,” it is nearly impossible to get all these competing tribes to work together for the common good. In fact the mind cannot comprehend that there is a common good beyond tribal interests.