If a positive factor for farming the land is growing food for a growing population, a negative could be
air pollution
deforestation
mining accidents
unemployment

The correct answer is B) deforestation.

If a positive factor of farming the land is growing food for a growing population, a negative could be deforestation.

Environmentalists consider that planet Earth has 30% of its territory covered with forest. The problem is that modernity is disappearing them by many factors such as cutting trees to make furniture and industrial uses, pollution, and climate change. Other important causes of deforestation are farming, grazing of livestock, urbanization, wildfires, and mining.  

Many countries have seen a dramatic decrease in farming lands, impacting the production of food for its inhabitants. Hunger is one consequence of this loss of land.  

it increased 6 percent and reached that in 1980