Be wary of "global problems" hetfield. Especially the passionate ones. These are generally the class of "issue" that has an agenda behind it that does not serve the people.
Something that gets my attention is the struggle with hunger, disease, and oppression, not to mention political tyranny and genocide.
If one thinks for a simple minute, and takes an objective and longish view, there are things we should be doing that we are not.
The Planet is warming? Worth a look? Certainly, but realize that we have disaster in our laps, and should be addressing these, prior to increasing harvests, improved comfort in the upper latitudes, etyc, if these even arrive in the next hundred years.
Hysteria is an unacceptable replacement for resolve.
Be Well.