Among the given choices, the only positive effect that may be thought off with the increase in level of CO2 in the atmosphere is the increase of plant growth. Carbon dioxide is an essential compound in the photosynthesis of plants. Therefore, the answer should be letter C.
An example of ATMOSPHERE affecting the BIOSPHERE. Atmosphere because it is AIR pollution and biosphere because it causes LUNG TISSUE damage.
In converting a number with the unit of meter into kilometer we must use the conversion factor 1 km per 1000 meters.This is because in 1 kilometer there are 1000 meters and then the unit to be converted is already in meter so we need to divide it for us to convert.