The oceans are becoming more acidic. While it may take hundreds of years before humans are directly threatened by anthropogenic climate change—through droughts, rising seas and fiercer storms–the effects of ocean acidification can already be seen.
Experiments suggest that lowering the pH of seawater, and reducing its concentration of carbonate ion, will reduce the growth rate of some organisms. Many of these creatures—from plankton and algae to mollusks and corals—form a vital part of the marine ecosystem and may already be threatened by global warming. Some of these organisms will adapt. Others may not.
Ocean acidification may be costly. Coral reefs provide up to $30 billion a year in economic benefits, as a draw for tourists and habitat for fish. Globally, fish are the primary protein source for about a sixth of the world’s population. The oceans also provide an enormous benefit to humans by stashing away a large part of the carbon dioxide gas we put in the atmosphere. If you were to put a value on each ton of carbon sequestered, this hidden service would come out to up to $600 billion a year by one estimate.
As an area of research, ocean acidification is in its infancy. Much of what we know comes from short-term experiments in the lab, making it hard to predict what the effects will be in a complicated real-world ecosystem. Scientists need to collaborate and standardize their research protocols and work quickly to document how the oceans are changing. This is an opportunity to make the dangers of climate change tangible to the public and to push policy makers and industry to set limits on global carbon emissions and develop a fossil-free energy system.