Provide Access To Clean WAter
Places like Africa don't have any source of clean water or the technology to desalinate water. 1 in 8 Americans Don't have access to clean water and as a result 2,000 children die per day.
The USA has technology already to desalinate water but it isn't "shared" with third world countries. Some non-profit organizations along with companies have developed charities or have technology to provide access to clean water. Some charities collect money whereas some companies like LifeStraw have a system in place where people in first world countries buy a LifeStraw and it gets sent to someone in Africa.
If first world countries can work together to provide access to clean water in third world countries. Even first world countries can do things to conserve the water that we have today because eventually fresh water will run out.