What are we shell-ebrating?

Today is Earth Day—a day dedicated to celebrating the planet we call home and raising awareness of environmental problems. The seeds of this day were planted back in 1969 when Gaylord Nelson, the then-Wisconsin senator, witnessed events like the Cuyahoga River catching fire and the Santa Barbara oil spill and decided that the world needed an environmental initiative. A year later, the first Earth Day event was held. Now, it has grown into an annual event with more than a billion people in over 193 countries taking part.
© Ralph Pace/Minden Pictures