Phil: kudos on sounding the fire alarm, as so many others have done. Unfortunately, too many lawmakers and titans of industry would rather have short term gain (money and power) at the expense of long term pain (facilitating climate disaster).
Don’t get me wrong, I’m a strong supporter of environmental protection and believe the world must unite to combat climate change. However, I would also point out that even without climate change there would still be serious mass extinction risks. You mentioned some above like super volcanoes — including at Yellowstone National Park — to colossal asteroid strikes to nuclear Armageddon and coronal mass ejections from the sun.
But in cosmic and geological timescales, humanity is living in a infinitesimal period of time, relatively speaking, between Ice Ages. The dinosaurs existed for about 165 million years, however, humanity is only about 200,000 years old. Now consider the universe is nearly 14,000,000,000 (billion) years old and the Earth is about 4.5 billion years old. Divide that by a few hundred thousand years to get a sense of the proverbial “blink of an eye” timescale in which we collectively live.
My point is that even if humans survived as long as the dinosaurs — and with a pristine climate and no mass extinction events — we would still face another inevitable Ice Age which would wipe out humanity (assuming we even lasted that long). That’s why futurist visionaries like Elon Musk are correct that humanity must become a multi-planetary species for long term survival. It’s at least promising that we appear to be moving in that direction, although it’s taking too long, as the clock ticks away to the detriment of humanity’s survival.