This figure, the famous Keeling Curve, shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. This curve is an essential piece of evidence that shows the increased greenhouse gases that cause recent increases in global temperatures.
This video addresses acidification of the ocean and the ecological and economic implications of the resulting pH change on marine life. It includes information about how ocean acidification resulting from increased absorption of CO2 from the atmosphere is affecting ocean species such as sea urchins and oysters. Scientists from the University of California at Santa Barbara discuss their experiments with sea creatures in acidic sea water. There is an associated lesson plan and classroom activity that has students test the effects of CO2 on water pH.
This video introduces phytoplankton - the base of the marine food web, the source of half of the oxygen on Earth, and an important remover of CO2 from the atmosphere. The video also explains how satellites are used to monitor phytoplankton and how warming waters and acidification negatively affect phytoplankton.