Carbon dioxide molecule, CO2, absorbing and re-emitting infrared

Carbon Dioxide, or CO2, is a linear covalent molecule with a central carbon atom and an oxygen atom on either side. Carbon dioxide is a major greenhouse gas. Although not as potent as some other greenhouse gases, it is abundant and is thought to be largely responsible for global warming and climate change...Photons of sunlight are shown coming from upper left and striking the ground. The ground then emits infrared photons that strike the carbon dioxide molecule. The molecule absorbs the photon and then re-emits one in a random direction, thereby scattering the energy that would otherwise travel out into space. This is the basis of the greenhouse effect...Absorption of Infrared Radiation by carbon dioxide happens because the carbon-oxygen bonds can stretch or flex at a frequency that allows them to absorb an infrared photon. There are a number of ways in which the molecule can oscillate. One type involves the bonds stretching and contracting like springs. The molecule can absorb an IR photon when this stretching is asymmetric. The alternative is for the bonds to flex. The flexing movement allows absorption at a longer wavelength. Because the CO2 molecule can vibrate in different ways it can absorb different frequencies of IR. This means that the infrared absorption spectrum of carbon dioxide shows two main peaks. Emission of Infrared Radiation by the oscillating molecule will be in a random direction. This will happen repeatedly over time as molecules absorb and then re-emit IR photons. Consequently, roughly half of the emitted photons will travel back towards the surface, thereby slowing the loss of energy into space.