Furthermore, is there any sensible, hopeful, safe, stable, productive, and generally happy society that has mass shootings and addictions/crimes of despair nearly everyday?
There isn't any first-world country with the number and frequencies of mass shootings or gun-related homicides the US does. 2/3 of gun deaths are suicides, which are a bigger problem of preventable acts of despair. Murder is entirely different. 54% of mass shooting are family-related. Roughly 40000 gun deaths in the US per year.
Comparing with other countries is ridiculous at best when not nonsensical. No country enables citizens to purchase weapons like in the US and no other country has hundreds of millions of weapons in circulation. Trying to make it look like a single variable problem is a joke.
And the grim prediction is rather than climate change, the real problem is population growth.
Population growth is not a massive problem: we already know that human population will hit a max of 10 billion people and from there start aging progressively and reduce over time.
This is the finest kind of denialism, and it is really going to bite us hard in about a hundred years at most.