Fortunately, climate change will likely not be the death of humanity as a whole. Unfortunately that is about the only good news. To be frank I'm not sure how to tackle this while being at all optimistic, so I'll try to just stick with spouting facts.
For climate change skeptics and people who just wish we knew more about what the future might look like, the Earth has actually experienced an event strikingly similar to the one we have put ourselves into. In just a few thousand years, a blink in the history of the Earth, the atmosphere became polluted with an amount of CO2 around the same as if we burned all the Earth's known sources of fossil fuels.
This event is called the PETM and it resulted in widespread extinctions in both marine and terrestrial environments. The sea surface temperature of the Arctic was around the same temperature as modern day tropical waters.
The Earth took around 100,000 years to recover from this incident and return back to normal. If nothing else, the ability of nature to bounce back after nearly anything is impressive. But this is obviously something we don't want to happen and 100,000 years is a long time to be stuck in an incredibly hostile environment. But before I give you an optimistic encouragement to fight global warming let me show you what makes our situation so terrifying.
The reason the before mentioned event occurred isn't fully known but there is a hypothesis. There are pockets of Methane locked in frozen water that may have been released by some kind of volcanic event that melted the ice containing them. This is referred to as the methane burp hypothesis. As I mentioned this is merely a hypothesis and might not account for the entire climactic change of the event. But methane is considered to be around 30 times worse than CO2.
It isn't much of a stretch to guess that some pockets of methane will be released as our glaciers melt. How impactful this will be remains to be seen, but it makes our future look far more terrifying.
So here is the part where I encourage all of you to work against climate change. While we won't see the real consequences of our actions for at least a few decades, we will only be able to lessen the damage of those consequences right now.