Final answer:
The human population is experiencing exponential growth, and new births alone are not responsible for this trend. Other factors like death rates and migration also contribute to the changes in population size. The current global population is around 7 billion.
Step-by-step explanation:
According to the given information, human population growth is said to be increasing at an exponential rate. This means that despite human reproductive rates being below their biotic potential, the population continues to rise considerably.
This growth factor is demonstrated by the fact that the global population has surged from 6 to 7 billion within only 12 years, whereas previous increases took much longer. For instance, it took 123 years for the population to grow from 1 to 2 billion.
To address part A of the question, no, new births are not solely responsible for the increase in population size. Other factors like mortality rates, migration, and advances in healthcare and technology also play significant roles.
To gain insight into the reasons for population growth, data on fertility rates, death rates, migration patterns, and socio-economic changes would also be beneficial.
For question 28, the statement is True. Some countries indeed have a negative growth rate, often due to factors like low birth rates, high death rates, or high rates of emigration. Regarding the current population of the Earth, the correct answer is C. Around 7 billion.