When it comes to the ways global climate change impacts the world’s oceans things like melting ice caps and glaciers, and what’s called thermal expansion — that’s when water takes up more volume as its temperature goes up — are probably what first come to mind. Or how increased water temperatures impact sea life, like recent, widespread coral bleaching events off Florida’s coast and around the world. Or even how changes in temperature and salinity can alter ocean currents, which are crucial for regulating global climate and weather patterns.
But, an overlooked aspect of this story is how increased levels of carbon dioxide in the atmosphere increases the acidity — or the pH level — of the world’s oceans. Each day, with the current atmospheric carbon dioxide levels, our oceans absorb approximately 24 tons of CO2. The average pH of seawater in the world's oceans is around 8.1 these days, making it slightly alkaline.
The global pH average has dropped by .1 since the early 1900s, primarily due to increased atmospheric CO2, which causes the pH to gradually decrease. And current, long term trends show that number continuing to decline.
While a .1 decline might not seem like a lot, it represents a roughly 30% increase in acidity. And researchers are concerned that if the trend continues marine organisms — particularly things like corals and sponges — will begin to suffer, and that could drastically disrupt marine ecosystems like the ones we rely on in so many ways here in Florida.
Click here to find a series of 'Ask IFAS' documents that explain how seawater chemistry changes as a result of elevated carbon dioxide levels.
Guests:
Dr. Lisa Krimsky, Water Resources Regional Specialized Extension Agent for Southeast Florida and a Florida Sea Grant Agent with the University of Florida’s Institute of Food & Agricultural Sciences (IFAS)
Dr. Joshua Patterson, Associate Professor of Restoration Aquaculture with UF/IFAS at the Florida Aquarium’s Center for Conservation
WGCU is your trusted source for news and information in Southwest Florida. We are a nonprofit public service, and your support is more critical than ever. Keep public media strong and donate now. Thank you.
