That is simply not true. Global average temperature has been stable for 10,000 years, since the end of the last ice age. It is that long-term stability that made the rise of human civilization possible.
When was that?
If you look at this estimate of temperature on Planet Earth[0][1] you can clearly see the last time the planet saw > +2C was the Pliocene.
Even if you look more closely at just the Holocene you don't see > +2C anywhere[2]
[0] https://upload.wikimedia.org/wikipedia/commons/5/5f/All_pala...
[1] https://en.wikipedia.org/wiki/Geologic_temperature_record
[2] https://en.wikipedia.org/wiki/Global_temperature_record#/med...
They don't? Which models are you referring to? The model forecast in James Hansen's 1988 congressional testimony was almost spot on.
https://www.realclimate.org/index.php/archives/2007/05/hanse...
> Scenario B and C had an ‘El Chichon’ sized volcanic eruption in 1995.
EDIT: Looking at the graph once again, he predicted in scenario B that we would see more than .6 deg C of warming between 2000 and 2020.
But it appears that we've only had about .3 deg C of warming in the past 20 years: https://climatedataguide.ucar.edu/climate-data/global-land-o...
This chart is to the same scale as in the realclimate link. As of 2020, we're about 0.1 to 0.2 degrees below the Scenario B forecast, at +1 instead of ~+1.15.
https://data.giss.nasa.gov/gistemp/graphs_v4/
What do you think a good 1988 model prediction would look like?
Looking again at your original link, Hansen's scenario B predicts a ~1.45 deg increase from 1988. So, in answer to your question, not that.
https://data.giss.nasa.gov/gistemp/graphs_v4/graph_data/Glob...
And, where do you see 1.45 C forecast for 2020 outside of Scenario A? Scenario B doesn't even come close to the 1.25 indicator line.
The NASA chart shows a rise of about .7 during that time.
This is simply false. The last time global average temperature was more than 2.7°C higher than modern times was over 100 thousand years ago.
If you instead only look at model runs with co2 levels close to reality you find that the models have done an amazing job of predicting current warming levels. 50 years more than one study showed 1C of warming by 2020 if co2 levels were around 420. Which is exactly spot on to where we are.
Climate modeling predictions are some of the most stunningly accurate predictions in the history of earth science and someone should have gotten a Nobel for it by now.
This temperature rise is totally out-of-context for us, and will cause a lot of pain.
The same increase over a century is disastrous, because infrastructure and capital doesn't change or move nearly so rapidly.
They will loose land, health, money etc.
People whoms homes will be burned etc.
We will experience future animal diversity reduction. This is something very depressing but depending in the Person how much you care for such things.
Also we will experience more dramatic Events as well. Like droights and lots of rain. The Impact on you might range from 'not leaving my flat today' to 'I lost everything'. Your surroundings will slowly change. Woods will start looking different.
And still we are not very certain about all those things. It could get much faster much worse through tipping points.
It also forces future generations to already plan their future accordingly: they will know that they will experience an increase of sealevel of 60cm and more.
If the AMOC collapses as we are already starting to see [0] then at least the European portion of the HN community will be deeply impacted.
If the American South West continues it's path of aridification [1] then plenty of HN member will be impacted as well.
[0]. https://science.howstuffworks.com/environmental/earth/oceano...
This prediction is for 6.75m of sea level rise or 22ft.
That said, why should we generously assume the models are correct? Because, despite the hundreds of lines of hand-waving in this topic, they have not proved to be correct.