The ocean, air, and climate could be thought of as a quot; common pool resource .quot; What is a quot;common pool resourcequot;?

The ocean, air, and climate could be thought of as a "common pool resource." 

What is a "common pool resource"?

The fear of having a "common pool resource" is that there will be over-use of the resource. This is called the "tragedy of the commons."

Hasn't the U.S. accomplish some reduction in CO2 emissions and reduction in other pollution? Isn't the real problem countries like China and India that use coal for energy? 

How can we solve a "tragedy of the commons"?