Tipping points are consequences of the consequences.
They are the feedback loops, where the heating takes on life of its own without help from humanity. When this kicks in, and scientists don’t know when, even the most drastic energy austerity will not be enough to stop continued heating of the earth. Global warming will be off the reservation, feeding itself.
Some examples of these feedback
Snow and ice is white which reflects sunlight back into space. As the ice of the North Pole is replaced with dark ocean water, more heat is absorbed by the ocean. Likewise, the reduction of glaciers, snow on mountains etc. means less radiation is reflected, heating is increased.Snow and ice reflect nearly 90 per cent of incoming radiation and are important to keeping the earth cool.
As the atmosphere warms, more water is evaporated and held in the air - humidity. While this is one of the factors driving more extreme storms, water vapor is also a greenhouse gas, thereby trapping still more heat in the atmosphere.
The heating of the oceans, as well as other kinds of pollution, is reducing the abilities of the oceans to photosynthesize. This means less CO2 is removed from the atmosphere and oceans and results in still more warming of the atmosphere and oceans.
There is something called Arctic Methane emissions. As permafrost (ground that heretofore has been frozen) melts, and glaciers in the arctic ice recede, methane and additional CO2 is released into the atmosphere. Part of this is just stored gases, part of it is a result of rotting biomass that was previously frozen. As the earth warms, more of these gases are released. More GHG, more warming the earth.
It is this kind of runaway greenhouse effect that is the scariest, threatens the livability of the planet in the future, and keeps climate scientists up at night.