“A Time for Sea Change”, produced by the Center for Ocean Solutions. November 29, 2015
It’s Time for a Sea Change:
The Impact of CO2 on Our Ocean
Will our children look back on the 2015 UN Climate Change talks in Paris this December as the sea change that saved our global ocean, or as a failed attempt to protect the resource that sustains billions of lives and livelihoods?
Lindley Mease and Larry Crowder
Looking for a Sea Change for the Paris Climate Talks
Carbon dioxide (CO2) levels in our atmosphere are the highest they’ve been in 15 million years. We know that climate change is transforming ecosystems across the globe on an extraordinary scale and at an extraordinary rate. For most of us, he phrase “climate change” conjures up images of heat waves, melting glaciers, hurricanes, droughts, and monsoon rains—but not changes in the ocean, its chemistry, and tiny plankton inhabitants.
The ocean plays a key role in regulating our climate by absorbing more than a quarter of the carbon dioxide that humans put into the air. We depend on the ocean for food, coastal protection, and the air that we breathe. And the ocean is struggling to keep up with rising CO2 levels, which has resulted in temperature increases, sea level rise, and ocean acidification.
Temperature Increases – The world’s oceans are warmer now than at any point in the last 50 years. Warmer oceans affect weather patterns, cause more powerful tropical storms, and can impact many kinds of sea life, causing species to cxpand into areas not previously occupied.
Sea Level Rise – Sea levels are rising both from thermal expansion and from the addition of water from inland glaciers, which are melting nearly everywhere at accelerating rates. A rise in sea level of just a foot or two could have significant negative consequences for islands in the Caribbean and the Pacific and for low-lying coastal areas along the continental U.S., such as the eastern shoreline of Cape Cod, the barrier islands protecting North Carolina, most of southern Florida, and the city of Boston
Ocean acidification is particularly damaging to the many organisms that use calcium carbonate to build protective shells. Collectively called “calcifying organisms,” they include some phytoplankton, and many invertebrates such as corals, sponges, marine worms, mollusks, and crustaceans. Increased acidity makes it harder for them to form shells. The shifts in pH could end up having a powerful ripple effect, dramatically altering the ocean food web and eventually affecting what appears on your dinner plate.
What Can We Expect from COP 21?
Analysis of plans put forward by nearly 150 countries suggests temperatures will reach just under 3°C by the end of the century rather than the 2°C target. This is bad for our oceans and for humanity as a whole. A recent scientific review emphasized that even a 2°C temperature increase will substantially alter the marine resources and services we depend on for our survival.
Can we do better? Let’s hope our world leaders pay attention to the call to reduce carbon emissions to protect our ocean from further warming and acidification as they finalize negotiations in Paris at COP 21. Reductions need to be meaningful enough to protect the integrity of our global ocean, one of the world’s most important ecosystems.