Global warming is a serious threat to not only the United States of America, but to humanity as a whole. If the Earth heats to the dangerous level it is expected to, more than our national security is at stake. But the homeland will come under fire if something is not done to slow global warming. Droughts are becoming increasingly common, as are heat waves. The fight for water in poorer nations, such as those in Africa, is only aggravating conflicts there. As we saw around the turn of the century, countries in turmoil spawn frustrated, angry people that can turn in die-hard terrorists willing to do anything. Global warming has to be slowed.
Placing a small carbon tax on emissions will not amount to much to the average consumer, but it will to big emitters. They will realize that they must invest in renewable energy or nuclear power. Carbon taxes are one flat tax that is predictable and easy to implement. And the tax revenue, which will be a decent amount, can be used for research into renewable energy and nuclear power.