 Ocean acidification is one of the most important problems facing the planet. As humans burn fossil fuels in our cars and factories, carbon dioxide is released into the atmosphere, much of that is absorbed into oceans. Oceans have now become 30% more acidic than they were at the beginning of the Industrial Revolution. It's not just something that is a problem down the road. It's actually causing problems right now. It's affecting so many different types of plants and animals, from the tropics to the poles. Everything from corals that provide the three dimensional habitat for all those fishes and nudibranchs and shrimp and everything else that live there, to the microscopic plants that provide food for many of the zooplankton around the world. To things like terrapods are very, very important food source for mackerel, for salmon, for a number of different species of fishes. And so there are knock-on effects to their predators. It's going to affect enough species negatively that they're going to be direct and indirect very serious consequences to pretty much every type of ocean ecosystem on the planet. That's a harbinger of things to come. And it's one reason that people have called ocean acidification osteoporosis of the sea. For thousands and thousands of years, oceans have been so critically important to people. Oceans were their grocery stores, they were their pharmacies, their playgrounds, their highways. They have been so fundamental to life on this planet that we've just come to take them for granted. And because they're so vast, we think they're infinitely bountiful, infinitely resilient. There are so many pressures on oceans now. Climate change, ocean acidification, overfishing, nutrient pollution. We're seeing more polluted beaches that are closed where people can't swim. We're seeing coral reefs that are bleached. We're seeing shellfish that are not able to reproduce. We're seeing massively overfished areas. In the 40-plus years I've been studying oceans, I've seen some really bad things. I've seen oceans become so degraded that it made me cry underwater through my mask. It was so depressing. But it doesn't have to be that way. I've also seen places come back to life because people cared, because they were willing to do something. They were willing to be creative, to engage others, and to be problem solvers, not just to walk away. That's what we need more of.