There are almost a billion people in the world without access to clean water. I pledge my birthday to change that.

As I approach my 40th birthday, I've never felt happier, healthier or stronger.

Sadly, there are so many people in the world that will never experience these emotions. They'll never have the freedom to go after their dreams because nearly 1 billion of them lack the most basic of needs - clean, safe, drinking water.

Women usually bear the burden of water collection, walking an average of 3.5 miles to the cleanest source. In fact, they spend more time obtaining water than any other activity in their lives. That's time they're not spending learning to read and write. Time they're not spending learning a trade or earning an income.

If they have better access to fresh drinking water, they'll be better able to improve their lives and the lives of their families.

So for my birthday, I'm asking you to donate my age in dollars. Or, instead of buying me a drink, buy one for someone in need. Every penny of the money raised will directly fund clean water projects in developing countries. And charity: water will show us exactly which projects we funded.

Help me give other people the opportunity to discover just how strong, healthy and happy they can be. Because only after our basic needs are met, can we have the courage to go after our wants and our dreams.