Is Atmospheric Carbon Dioxide Causing Global Warming?

Every knowledgeable scientist will stipulate that global temperatures are rising (0.7$^{\circ}$ the last century). There are those that see a universal scientific consensus that atmospheric CO$_2$ is the culprit; they have put in place a cap-and-trade system to forcibly reduce anthropogenic CO$_2$ in the USA. What is the scientific evidence behind this volatile issue?