It has been known that high levels of carbon dioxide in the air causes health and environmental hazards, but a new study shows that high concentration of Carbon dioxide might actually be helping plant cycles, resulting to a greener earth.

According to their press release, researchers said carbon dioxide is one of the main ingredients in plant's photosynthesis. The green leaves in plant uses energy from sunlight to process carbon dioxide from the air and water and nutrients from the soil. With these, higher levels of carbon dioxide in the air can also mean more food for the plants making them greener.

But researchers noted that carbon dioxide is not the only factor responsible for the greening effect. Other drivers include nitrogen fertilization, land management and climate change.

For the study, the researchers gathered 33 years worth of data from NASA's Moderate Resolution Imaging Spectrometer and the National Oceanic and Atmospheric Administration's Advanced Very High Resolution Radiometer instruments to help determine the leaf area index. They then analyze the extent of carbon dioxide's contribution to the greening effect by using computer-generated models mimicking the plant growth observed by the satellite.

The researchers then found out that about 32 percent of the total surface area of the earth is covered in vegetation, occupying about 85 percent of all ice-free lands. This greening effect could cover twice the size of the mainland United States. The researchers have also uncovered that carbon dioxide is 70 percent responsible for the greening effect, followed by nitrogen (9 percent), climate change (8 percent) and land management (4 percent).

Even with its beneficial effects to the plant, researchers warn that carbon dioxide in overall is bad for us. High concentration of carbon dioxide in the atmosphere traps the heat inside the earth, leading to climate change, in which can result to global warming, melting of the ice caps and severe weather effects.

Researchers also mentioned that the beneficial effect of the carbon dioxide is only temporary due to the ability of the plants to adjust to rising carbon dioxide levels diminishing fertilization effect over time.

The study was conducted by a team of 32 researchers from 24 institutions in eight countries, and was published in the journal Nature Climate Change.