Keeping the taps running: Already, a third of the world's population endures some form of water scarcity. In addition to being a critical health and environmental issue, competition for fresh, clean water could also spiral into conflict.

Ending micronutrient deficiency: It sounds like a high school science project, but the lack of access to essential vitamins and minerals afflicts over 2 billion people worldwide, and can lead to serious health disabilitie

Saving the fish: The world's oceans could be empty of commercial fish by 2048 if current trends continue. Only one-hundredth of one percent of the world's oceans is fully protected through marine reserves.

Fighting for refugees: More than twenty million people around the world have been displaced from their homes by conflict, human rights abuses, and persecution. Millions languish in refugee camps while the developed world bickers about who's obliged to do what.

Tackling child labor: