Capturing carbon dioxide — Carbon dioxide levels in the atmosphere have reached record levels, smashing the 400 parts per million milestone and continuing to rise. While there are other greenhouse gases as well, it is carbon dioxide that plays the largest role in global warming, and it is the gas that lingers the longest in the atmosphere. There are two fundamental strategies for limiting the gas – to reduce emissions or to remove carbon dioxide from the air. The Intergovernmental Panel on Climate Change (IPCC) says we need to do both.