The use of living plants to withdraw harmful substances from the environment is known as ______?

Plants can absorb harmful substances from the air, such as
carbon dioxide. When this happens, it is called photosynthesis.
Besides carbon dioxide, plants also absorb other things such as water, light,
etc.

This process takes place with plants, algae and
various kinds of bacteria ( href="http://en.wikipedia.org/wiki/Cyanobacteria">cyanobacteria). The
plants successfully absorb harmful things like carbon dioxide and convert them naturally
into energy—as organic compounds like sugar. By using carbon dioxide and water, plants
are able to produce oxygen, which the plant releases as waste, which is obviously a
positive outcome for air-breathing creatures like human
beings.

When global warming began, the introduction of
aerosol particles into the environment led to a growing concern of the affects of these
particles on the earth because of the reduction of sunlight (called "global dimming")
they caused. However, a recent article in ScienceDaily notes that
plants are doing better than ever under these conditions, probably better than they did
a hundred years ago. Instead of getting direct sunlight, plants are bathed in a
scattered, reflected light, which is better for the
plant.

As scientists find ways to clean up the environment,
they will now need to study the effects the clean up will have on the world—in
particular, plants, as plants continue to remove dangerous substances from the world
around us—scientists will not want this to change.