The maximum population that an area can support

it's called carrying capacity

Explanation:

Carrying capacity can be defined as the number of a biological species in an environment, its the maximum population size of the species that the environment can contain or sustain in the long run, given the food, water, habitat and other requisite available in the environment.

If there are more organisms in an environment than the resources available can sustain (food, water and habitat), then such environment has exceeded it's carrying capacity.

it is very hard for the climatologists to precisely predict how will the global temperatures be changing so there's lots of models, some of which differ significantly, this is due to multiple factors, and probably the most important is the human activity.

humans have been a key factor in climate change around the globe since the start of the industrial revolution, and in the past few decades the consequences are becoming more obvious. there's lots of emission of pollutants in the atmosphere as well as changing the environment on the surface itself, so it's really hard to predict how will that go in the future because there's some countries that are reducing the damage and are going towards green energy, while others are stubbornly continuing with pollution and damages to the environment.