Which of the following is true? question 15 options: 1. around 1500ad, the human population began to reach carrying capacity. 2.around 1500ad, the human population began to decrease. 3.around 1500ad, the human population began growing more rapidly. 4.around 1500ad, the human population began to level off.

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c.carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit