Although cap-and-trade is our second favorite solution, we prefer a straightforward fee. A carbon fee sends a predictable price signal that is not subject to market fluctuations and which enables businesses and consumers to plan their energy investments. Whereas cap and trade caps the emissions the price fluctuates. A big concern is international coordination and harmonization of climate policies. The problem of climate change is worldwide and an approach is needed that can accommodate the needs of emerging economies which may not have the infrastructure to monitor and enforce cap and trade regulations. A fee more easily lends itself to border adjustments between countries with different or no carbon fees, enabling agreements that can be harmonized worldwide. Undoubtedly, the biggest problem is offsets, which can be manipulated, double-counted, and sometimes difficult to measure and verify.