Explanation:

For all of human history, fewer than a million people populated the Earth at any particular time. Today the population of the Earth is nearly 7 billion people. There are two major phenomenons that triggered the remarkable increase in population size are agricultural revolution and industrial revolution.

The two phenomena of agricultural and industrial revolutions triggered a rise in population size.

Agricultural revolution resulted in the increase in population size. When humans started growing crops, live on farms and domesticate animals, the need for more food was met by the agricultural practices. Soon the agricultural practices improved and resulted in the increased production of food. The improvement of farming techniques helped in feeding of large populations. The availability of more food allowed an increase in population size as the health quality also increased due to more nutritional value of the crops grown.

Industrial revolution began in the mid- 1700s and it brought advancement in technologies, medicines, sanitation and other areas of research beneficial for mankind. Due to industrial revolution, the mass production of goods and enhancement of food production also occurred through use of fossils fuel. The improvement of farming techniques helped in feeding of large populations. As technological advancements increased, the health of people also increased due to which the death among populations decreased.

There are some positive impact (benefits) of agricultural revolution on environment and ecosystem. The preservation of land to grow crops and obtain economic goods like wood, timber, fruits and other products, led to the preservation of woodlands and forests. This resulted in the reduction in carbon dioxide generation as plant population increased.

The positive impact of industrial revolution on environment is that it led to the extraction of large scale energy from biomass which does not contribute to the global warming as the CO2 released by biomass is again taken up by plants when they are re-grown.

There are some negative impacts of agricultural revolution also. The increased crop production led to the destruction of natural habitats and thus decreased biodiversity which causes ecological imbalance. Chemical pesticides used to improve crop yield led to water and soil pollution.

The negative impact of industrial revolution environments is that it resulted in the air and water pollution as the effluents and smoke coming from the factories is released into the environment.