carbon dioxide_250字

　　Carbon dioxide is one of the most important atmospheric heat-trapping gases.Higher concentration of Carbon dioxide in the atmosphere will lead to global warming and cause uneven flood and drought or weather.It may even cause sea level rise.The water would drown a large number of coastal cities ,dangerous of us.But there is also a research point out that carbon dioxide has many advantages.Such as increasing the carbon dioxide can give plants "fertilization".It is beneficial to thegroup of plants.But there must be a premise that the plants is alive.If the soil is polluted ,plants died then we have lost release oxygen into the atmosphere "oxygen factory " and "air purifier ".In short carbon dioxide isvery important to us.