Carbon dioxide is an essential raw material for plant photosynthesis, and its content increases, which is beneficial to plant growth. Carbon dioxide can be used as chemical fertilizer for greenhouse vegetable cultivation to increase crop yield.

Carbon dioxide can be used as an oxygen source in diving and aviation.

Liquid carbon dioxide has a broad application prospect. Using liquid carbon dioxide as the medium for extracting natural compounds from some plants or plant sources will not only destroy the bioactive substances contained in the raw materials, but also contain no residual medium in the products. By spraying liquid carbon dioxide to demist the airport, the demisting efficiency is hundreds of times higher than that of solid carbon dioxide. Using carbon dioxide instead of traditional organic solvent for painting can effectively reduce the amount of harmful substances released into the atmosphere during painting.

In the high-tech field, carbon dioxide also has its place. Using carbon dioxide instead of He-Ne for laser treatment can reduce the pain of patients and save costs. Extracting lecithin from egg yolk with carbon dioxide has considerable economic benefits. Carbon dioxide can be used to wash clothes, and it does not pollute the environment and has a wide range of sources.

The greenhouse effect caused by the increase of carbon dioxide melts polar glaciers, leads to the rise of sea level, endangers coastal cities, salinizes coastal land and increases the difficulty of development. The rising temperature has also melted the snow on some hilltops, reduced the water volume of rivers with snowmelt as their water resources, and even caused water cut-off, which affected the production activities in these areas.

The rise of atmospheric temperature causes some algae plants in the ocean to absorb carbon dioxide.

Excessive reproduction causes the death of phytoplankton that absorbs carbon dioxide, indirectly affects the reproduction of fisheries, and makes the increase of carbon dioxide in the atmosphere enter a vicious circle.

To sum up: whether the increase of carbon dioxide is good or bad depends on how humans use it. As long as we follow the trend and turn harm into benefit, we will certainly make carbon dioxide a useful contributor to mankind.