Explain why population settlements changed over time ?

Over time people move to other places depending on their opportunities.

Explanation: If someone wanted to be a farmer they would settle down in a more fertile area where they can get more land. and someone who wants to be a lawyer or doctor would settle in a more busy area in the city.

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.