Even though ocean acidification does not directly affect humans, we will directly feel its secondary consequences. Losses of photosynthetic organisms and smaller predators will affect the entire marine food web. Economically important food species may become scarce. Coral reef die-offs will not only damage the food web but may also harm marine organisms important for medical and technological developments. Fishing- and reef-related tourism will suffer, and tourism's support industries will also. Biodiveristy losses will cause current and future setbacks that are not completely quantifiable.
The United States' commercial fishery alone brought in 9.5 million pounds of fish worth 4 million dollars in 2006. Fish are an important source of protein for much of the world, and many Asian, African, and northern European countries get more than 20% of their protein from fish (Food and Agriculture Organization of the United Nations, 2006). Decreasing productivity of the ocean fishery will impact a significant portion of the world's population.
Losing coral reef protection along tropical and subtropical coasts may increase the likelihood and magnitude of damage (Climate Change Futures..., 2005) from storm-driven waves and surges. This will raise coastal residents' insurance rates. Coral reef losses may also alter coastal water cycles, making seawater more likely to intrude into coastal aquifers (Climate Change Futures..., 2005). This may then affect coastal nutrient cycling, worsening problems like eutrophication and harmful algal blooms
[Another thing to think about is whether we have a moral obligation to preserve the world intact for future generations....]