What 1997 global agreement to reduce greenhouse gases was signed by virtually every country in the world except for the united states?

Kyoto Protocol

Explanation:

The Kyoto Protocol, which got its name form the location it was signed at, in Japan, was signed in 1997 and enacted in 2005.

Its goal is to reduce the greenhouse effect gases by about 6% for 2012 and about 20% by 2020.  The targets vary a bit depending on the country, based on its past pollution rate and the development of its economy.

The greenhouse gases are linked to the climate warming, which amplifies extreme meteorological events.