Part D Based on your examination of the population pyramids of 1965, 2015, and 2035, what can you say about the overall shift and progression of the

world's population? What concerns might you have about the changes in data you've seen in the world population during this 70-year span?

Population is entering the stage 4 of demographic transition in period of 70 years.

Explanation:

World population pyramid in 1965, shows a high birth rate and high life expectancy which is more for females and fewer for males. A total population of 3, 339,583,510.  While the population of the bell-shaped pyramid which has a low birth rate and high life expectancy due to education and better health care. Has a total population of 7,379,796,966. The population projection for the year 2035 is cup-shaped or wedged that is a declining birth rate and almost at stable population growth having a total population of 8,887,524,229. All this suggests that the population is moving to form the high birth rates to low birth rates and later on both the birth and death rates are getting stable over the period of 70 years, as the developing nations have implemented family planning and other measures.

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen