Oceans generate 70% of the oxygen in the air, and absorb much of its carbon dioxide. They drive the climate, the weather and the chemistry of the planet. Our oceans occupy over 2/3 of the planet’s surface and provide a home for most of the creatures on Earth. Unfortunately, our knowledge of the ocean is less than our impact on it. It isn’t too late to expand on our understanding of the world’s oceans, and to use that knowledge to effect positive change.
Source: Mission Blue – Oceans Overview