all life is in serious trouble.

I honestly doubt it will lead to our extinction.
Why? Well mainly because we have the ability as a species to quickly adapt to many variables in our environment with our ability to problem solve quickly.
That is something no other species has probably never been able to do on this planet.

still its a grim future by any measure without major change

Humans have come close to extinction before, and all other hominids are gone. Our track record isn't as good as you're assuming, and we're probably at our most vulnerable in the lifetime of our species.

Just a few hundred years ago, the majority of people had basic survival skills. They could forge weapons and tools, grow crops, tend domesticated animals. Now, we have large populations completely dependent on distribution systems for everything they eat and drink, without the slightest notion how to fend for themselves if that system collapses.

We've flourished precisely because we're in a interglacial era of mild climate. A planet in extreme is going to kick us back to the stone age, which won't provide many protections against weather gone wild.

For example we did not know how to sterilize and store food as well as we can now.
Plus we were still in the hunter-gatherer stage back then and did not have the knowledge we have now on how to grow our food.
All in all assuming there is still enough oxygen in the atmosphere and enough water to survive on our species will likely continue to exist.
We will go extinct eventually of course because nothing lasts forever but I doubt it will be due to climate change anytime soon.

People have been preserving food for tens of thousands of years, and I'd venture that the average Paleolithic man or woman was far better at it than the average person living an urban environment. We're fine as long as we have electricity and the internet, but we've largely lost the ability to survive without significant technological support. Modern society seems powerful but it's built on a very fragile surface.

As for extinction, it's very rarely an overnight event for any species. Of the five mass extinctions, four of them took thousands of years to unfold (the fifth may have taken out the dinosaurs in a much shorter timespan due to the asteroid strike). Humans could linger for a few hundred years, even a thousand, and still be wiped out by the escalating effects of rising CO2. The carbon we're spewing into the atmosphere right now is going to be around for thousands of years, and we won't feel the full effects of today's output for another 50 years. Every day afterwards makes that reckoning even more extreme.

What most people are overlooking is that climate change doesn't stop at the end of this century. "By 2100" is a catch-phrase that tries to frame the climate emergency in a way that people can grasp, but our current trajectory of rising CO2 is going to barrel right through the end of this century and into the next. Humans could be living in Hell on earth by then.

can it and sterilize it for longer shelf life nor did they have the medical knowledge we have now.
Sure they had some things that worked like peat moss but they did not know why it did what it did to help with infections.
No, overall I suspect what climate change is likely to cause is massive wars and huge loss of life as nations struggle for resources and people are forced to find new places to live as the coastal areas are flooded but humanity itself is likely to continue on for a long while after that.
Unless of course we experience something like a massive impact from a large comet or we are really stupid and develop and release an engineered virus that wipes us out.

The Everstorm is coming. This will not be fun.

Even if these denier clods have their own houses burned to the ground in a raging, biblical drought caused wildfire and then have it inundated by rising sea levels, they'll still deny climate change is caused by human activity. They'll just fire up their mega SUV and drive away. We have a whole generation of people who are hopelessly lost to reason and reality. Lost. The sooner they die off, the better.

EVERY projection allowed to be published was the least damaging that the data could possibly support, the mid-line and worst case data was effectively hidden or pooh-poohed as "alarmist".

The CO2 levels are startlingly above even the highest "safe" projections now...the glaciers are all but gone in many areas....the coral reefs are dying or bleached already....aquatic life, much like avian life and insect life is already in full extinction-level collapse.

If anyone honestly thinks that have a chance of a) surviving this calamity AT ALL or b) surviving it while remaining tied to the death cult of global capitalism is frankly part of the problem. We do not need a Green New Deal, we need a damn new governing philosophy from top to bottom, based on true stewardship of resources and equality instead of the gilded age we are dying from and for...

We cannot even get people to agree that this is REAL - while Australia burns and JANUARY tornadoes rip the USA south and areas see temperature swings from the 60's and 70's to the teens in 3 days. The evidence is EVERYWHERE and still denialism reigns supreme in policy matters and actual actions.

Western society is over. We're just hugging the corpse and waiting for the diseases from its decay to finish us off.

And so much denial = no action where it could help

Heartbreaking but true!