A new study found that the levels of greenhouse gas have been increasing worldwide. Researchers had used spectrometers to calculate the levels of carbon dioxide in the planet's atmosphere between 2000 and 2010.

The study was conducted by a team of researchers led by Dan Feldman of the Lawrence Berkeley National Laboratory in California. During the study, the researchers measured the amount of infrared radiation absorbed by atmospheric gases. They found that increasing levels of carbon dioxide gas have been warming the surface of the earth through the greenhouse effect.

According to the study, greenhouse gases like carbon dioxide and methane absorb infrared radiation that would be sent into space, in a way a greenhouse traps heat. The researchers had measured the radiative forcing at two locations: in Oklahoma and above the Arctic Circle near Barrow.

The researchers used spectrometers and followed infrared radiation arriving on the surface of the earth. The greenhouse gases in the atmosphere absorb and scatter the infrared radiation. As spectrometer emits and absorbs energy at very specific wavelengths, it can recognize carbon dioxide.

According to the study, at both locations, carbon dioxide in the environment increased by about 22 parts per million from 2000 to 2010. Parts per million refers to the volume of carbon dioxide molecules within a million air molecules. The study found that infrared energy's levels also increased during 2000 to 2010 due to being scattered by carbon dioxide. Increased level of carbon dioxide in the atmosphere resulted in more infrared energy reflected back to the planet.

The researchers ruled out warming from other sources like water vapor, clouds or weather. Feldman said, "This is clear observational evidence that when we add carbon dioxide to the atmosphere, it will push the system to a warmer place".