As another example of a public good, consider global weather observation. In this case, information gathered by one country generates external benefits when it is shared with other countries. Satellites, nomadic buoys, and weather stations monitor weather in different parts of the world, but no single organization gathers all the information to reveal the big weather picture. Another problem is that the uninhabited parts of the world, in particular the vast oceans of the Southern Hemisphere, receive little monitoring. This makes it difficult to observe the interactions between oceans and atmosphere, and difficult to measure any changes in sea level that might be caused by global warming.
In recent years, the United States has taken the lead in encouraging cooperation and the sharing of data collected by different organizations around the world. The experience of coordination in monitoring El Niño, the intermittent ocean current that affects weather in the western United States is encouraging. According to the National Oceanic and Atmospheric Administration (NOAA), early warnings of a change in the current in 1997 98 reduced damage to the California economy by about $1.1 billion.