The most important type of science in this day and age is the type that can bring clean water to third world countries. Water is the source that every living thing is driven to consume. Water is the most important thing to the human race. In fact you can survive weeks without food but you cannot survive weeks without water.
Even though water is the single most important substance to the human race, most third world countries still go without access to clean running water. Consider the fact that we need water to drink, for hygiene, cleaning clothes, agriculture, sanitation, and cooking.
Many families in third world countries walk miles each day of their lives traveling to water sources that are infested with water born diseases. As a result, 4,500 children die per day from unclean water. Often families with single or disabled parents have to pull children out of school so they can fetch water resulting in the accumulation of smart children who never had the chance to go to school.
Science can assist such countries in providing clean water for their citizens. Projects like the Water Project and Global Giving and many others struggle to get clean water to Third world countries.