if you link into the demographic transition model(don't know if you have heard of it but ) the birth rates are much lower in developed countries but also think about how useful theses countries are t the rest of the world - japan export many equipment , cars, electronics - Toyota etc., the US have the biggest silicon valley used for electronic - apple and other tech companies use them - think of it that way
People here in America are used to more personal space because it is not over populated. But in other countries with crowed houses and overpopulation you would not even be able to walk in your own space.
Upwelling is a process of the winds that drives away the warm water from the surface and bring up the cold and dense water from below.
Obliquity is the nature of the axial tilt of the earth i.e 23.5 ° Due to the equator bulge and other properties of the earth.
The thermohaline circulation is the global circulation of the waster that is created by the gradient flow of the surface heat and the freshwater influxes.
Milankovitch cycles are the effect of the changes in the earth's movements in climatic patterns over a thousands of years period.
Eccentricity is the orbital rotation of the earth around the sun on its axis and has more of a circular elliptical path.
The precession is the change in the orientation of the axial tilt of the planet in reference to the rotating body.