To avert global greenhouse warming, it is necessary to either reduce emissions of the gases which cause it and/or sequester the gases that have already accumulated in the atmosphere. By far the most important gas involved is carbon dioxide. Two major strategies to reduce emissions of carbon dioxide and five for sequestering the carbon to remove it from the active carbon cycle are discussed. There can be several more. Nine techniques are discussed to help add carbon to soil organic matter. If each of several different strategies can mitigate 5 to 10 or more percent of the problem, the problem will become small. One of the best strategies to sequester the carbon is as soil organic matter.