Is the major issue here that 3 degrees Celsius is like an average so all the hot tropics places just become uninhabitable whereas temperature rises are more moderated in higher latitudes?

Also how much faster and higher will that number go with all the data centers? Can't imagine it not just getting worse.

One major issue is the extreme difficulty of being precise about tipping points.

Eg: Have you seen a train derail? A couple of degrees of tilt - nothing .. and then .. whoops.

The global climate has been 'stable' about mean values for the bulk of human written history and development of urban civilisations. The planet now hosts 7 billion+ people, largely urban, and feed by a century of stable agriculture patterns write large.

The disruption of that will have a major impact across the human population of the planet.

The tipping points, when they come, are related to the significant loss of polar ice, and the beginning of positive feedback of atmospheric insulation factors other than CO2.

Melting ice, the transformation from near zero degree ice to near zero degree water, takes up a large amount of the energy from the sun trapped by increasing insulation. The energy used to melt X tonnes of ice, if no ice can be melted, will instead raise the temperature of X tonnes of water by some 66 degrees C (or there abouts - worth looking it up exactly).

Increased land and sea surface temperatures releases methane from peat bogs and tundras, and increases the water vapour content of the lower atmosphere.

Both of these things increase the insulation factor of the atmosphere to a greater degree than CO2.

It’s sort of all over the place but it’s mostly the other way round. The poles might see like +5-8c. It’s also the overall temperature. Today’s high temperature where I am is 33 and the low is 25. 33 isn’t super unusual, maybe a dozen days a year. 25 as a low though is crazy high even on days historically above 30. It all averages out to +whatever.

For temps by latitude/region this source seems ok on a quick search https://scied.ucar.edu/interactive/compare-climates-regional...

Among _many_ other things, 3 degrees Celsius globally means more evaporation over oceans, which makes the air denser.

Denser air carries more momentum, which means more frequent (and more severe) hurricanes.

As I understand it just means there's a lot more energy in the atmosphere. Like imagine the amount of energy it takes to increase water temperature in a pot by 3° and scale it up to the planet. All that energy makes everything bigger, badder, and less predictable. Longer, dryer droughts; bigger, longer winter storms, etc.

There's a lot of bad things that happen at 3C.

The first is that 3C represents a lot more energy in the atmosphere. That translates to more water evaporating from the oceans creating bigger more violent storms (think more frequent flash floods).

It changes the ocean currents which can be really bad. Right now Europe is warm for it's latitude because of a weakening current from the equator to the UK brings a lot of heat. If that completely collapses, Europe can enter an ICE age.

The rising temperature also ends up weakening the vortex of the north pole which mostly keeps the arctic temperatures sealed up north. As that vortex weakens, spills of crazy blizzards can hit unusual places pretty hard. The winter storm in 2021 is an example of that happening.

Then of course there's the potential melting of the ice caps which will release a lot of methane into the atmosphere (speeding up warming). That will ultimately cause sea levels to rise which won't be great for the state of Florida.

Mass migration, crop instability, more frequent and more extreme weather. It's just a combo of bad things that all come together at once.

The most extreme warming happens at the poles, doesn't it? Plus increases in volatility on top of a rising baseline, so more extreme heat wave peaks even in temperate climates that don't change as much on average.