We do have approximate world temperatures for a long time. If you look at the last 2000 years, we are currently experiencing a massive spike in temperatures and it does align quite well with the industrial revolution where we really started to pump out nasty amounts of CO2.

If you look at the charts for as far back as 11,000 years ago, it does look grim: https://www.theatlantic.com/technology/archive/2013/03/were-screwed-11-000-years-worth-of-climate-data-prove-it/273870/

However, if you look back at the last 500 million years, we are actually in a cold-snap: https://www.climate.gov/news-features/climate-qa/whats-hottest-earths-ever-been

Just looking at those two points is extremely confusing for some people. My points of view on this are:

1. Climate change is and always has been a thing. It can change quite rapidly or quite slowly. It can be impacted by biology or other natural phenomenon.

2. The earth will absolutely survive huge swings in climate changes and has done so for millions of years. We, as humans, probably won't though. However, we are generally intelligent when it comes to survival, so we have that going for us.

3. What some people don't realize is that we are changing the world temperatures at an accelerated pace with no plan to mitigate it. The biology of the past has poisoned other life with excessive oxygen and also excessive CO2. Lots of things died and some things evolved. We are just doing the same thing on a much grander scale with more exotic ways to generate waste gasses.

4. We don't really have any large CO2 sinks right now. Contrary to what some say, planting more trees won't slow things down. While plants love CO2, anyone that has ran a greenhouse or grow tent with supplemental CO2 will tell you that it can be tricky to manage excess humidity while also keeping temperatures down. Higher temperatures are probably going to kill off a fuck ton of plant life, so there is that.

Charts are confusing and we need better ways to present data other than "average world temperatures over the last x years". They simply do not tell the full story.

Additionally, people fail to realize the difference between seasonal weather and average climate. Unfortunately, people with good intentions also mix the two up. Also, It's super easy to think "this year" has had the worst weather. Humans have really bad memories and do not hold detailed data points very well. One good year followed by one bad year just feeds extreme opinions and it's seriously annoying.

Contrary to what some say, climate is changing. It always has and always will. Our tolerance as humans is quite good, actually. However, when you look at the big picture, we live in an extremely narrow band of survivability in our own atmosphere and fucking that up is very much possible.

Failure to understand data is why climate change deniers exist.