and yet this sort of watery deep, , as it werere, is still basically unknowown to us peopl. >> not only do almost 3 billion people make their living with work associated with the oceans, but it's a major source of protein in the human diet. 70% of the oxygen we breathe comes from the oceans. we need the oceans, the oceans don't need us. that'ss the fundamental disconnect. the biggegest silent threreat to the o oceans from humumans is on acidificatioion. it's happening. it's happening 1 10 to 100 t tis fasterer than at a any time in e last 50 millioion years. i in f, sincnce the 1900s, e early 1900, the ocean n is 30% moracacidic. >> ph, or reallly the a acidityf the ocecean, is changing as a resusult of carbrbon dioxide n the atmosphere. this is ultimately sosort of ththe eviln of climamate changnge. >> we look at global warming. we talk about the changes in our atmosphere. we need to look at the changes in our ocean. >> we've been pumping c carbon dioxidede into the atmosphere, especially since the indndustril revolution, with the burning of fossil fuels. anand that c carbn dioxide has