Admit it: You enjoy emitting carbon. It keeps you warm in the winter, cool in the summer, powers the device you're using to read this article, and gets you almost everywhere you want to go.
In short, nearly everything we do emits carbon and many of these things -- like breathing, for example -- we'd prefer to keep doing. But most scientists agree that all this carbon is putting a fleece blanket around the Earth, warming it up in a way that winds up killing polar bears (who are losing their frozen habitat) and sinking the Pacific island of Kiribati (which is being drowned by rising sea levels).
Therefore, carbon sequestration is a tantalizing idea: If we're not going to stop emitting carbon, maybe we can stick all this carbon someplace else, where it won't hurt anyone.