News Section
Stories from Climate Central's Science Journalists and Content Partners

Ocean Acidification Threatens Food Security, Report

Repost This

Pakistan, Thailand, the Philippines, Iran, and China are among the top 50 nations whose food security may be threatened by the effects that the rise of manmade carbon-dioxide (CO2) gas emissions are already starting to have on fish and shellfish, according to a new report by Oceana, an international ocean conservation organization.

Coral reef ecosystems are especially susceptible to damage from the increasing acidity of ocean waters. Click on the image to see a larger version.
Credit: NOAA Photo Library.

While global warming is expected to affect the food supply of many nations by increasing drought, heat waves and torrential downpours, this report focuses on countries that depend heavily on the oceans for sustenance.

“Fish and seafood are an important source of protein for a billion of the poorest people on Earth,” said Matthew Huelsenbeck, a marine scientist with Oceana, “and about three billion people get 15 percent or more of their annual protein from the sea.”

In order to assess which countries are at greatest risk, Huelsenbeck and his colleagues looked at two entirely different effects of CO2 on the oceans: the warming caused when carbon dioxide traps extra heat from the Sun, and the rise in the acidity of seawater as it absorbs some human CO2 emissions to form carbonic acid.

Increased acidity makes it harder for shell-forming organisms, such as clams, oysters, and corals, to build their shells. That in turn affects people who depend on these sea creatures for food, or who eat the fish that depend on coral reefs for their habitat.

Rising temperatures, meanwhile, have forced some fish to migrate away from their normal territory. “Some fish just don’t like it too hot,” Huelsenbeck said. A recent NOAA study, for example, found that Atlantic cod populations in the Gulf of Maine are shifting northeastward in response to rising ocean temperatures. In fact, the waters off the coast of New England were the warmest on record this year. Fish migration may not be a big problem for countries with modern fishing fleets, such as the U.S., but poorer nations with more local fishing fleets can’t simply follow their food supplies as they swim away.

The disparity in resources between rich and poor countries, combined with projections of population growth through 2050 and the percentage of the population that’s undernourished, were the main factors that went into the national rankings, under the heading: “Lack of Adaptive Capacity.” Another main factor was “Exposure,” meaning the vulnerability of nearby seafood supplies to both warming and acidification. The final factor in the rankings was “Dependence” — the degree to which each country relies on protein from the sea in its mix of food sources.

CO2 from the atmosphere gets absorbed by the oceans, and chemical reactions take place that break it down into carbonic acid, which harms marine life. Click on the image for a larger version.
Credit: NOAA.
 

Put all of these factors together, and the most endangered country in terms of marine food security turns out be the Maldives, the low-lying island nation in the Indian Ocean that’s already under imminent threat from rising seas. Pakistan, at number eight on the list, is the worst-off of major countries, followed at number 10 by Thailand. Iran occupies the 27th spot, the Phillipines are ranked 34th, followed by China at number 35. Peru and South Africa also are ranked among the top 50 countries lacking adaptive capacity.

While it’s possible to deal with some aspects of climate change through adaptation — building sea walls to keep out the rising ocean, for example, or irrigating crops affected by drought — there’s really no way to de-acidify the ocean once it’s undergone that chemical change.

Even the wildly ambitious geoengineering schemes that propose to cool off the planet by reflecting extra sunlight back into space would do nothing to keep seawater from growing progressively more acidic. “Reducing emissions,” Huelsenbeck said, “is the only way to prevent it.”

The report urges governments to “establish energy plans that chart a course for shifting away from fossil fuels and toward clean energy production” and to end fossil-fuel subsidies — but environmentalists have been saying pretty much the same thing for years, with little effect.

The authors also urge a reduction in overfishing and other destructive fishing practices. They call for the establishment of marine protected areas where fishing is banned entirely and pollution is cut back dramatically, to give marine populations at least a fighting chance of staying somewhat healthy. And they urge fisheries managers to take climate change and ocean acidification into account when putting together fishing regulations and policies.

These suggestions are ambitious as well, but they may be a more realistic bet — for the moment, at least — for keeping the nations at greatest risk from losing some of their crucial supply of nourishment from the sea.

Related Coverage
This Is Your Ocean on Acid, and It’s Not Pretty
Geoengineering Faces Dilemma: Experiment or Not?
Climate Change and Global Food Production

Comments

By Stephanie Bedsaul (Ponte Vedra Beach/Florida/32082)
on September 25th, 2012

“Out of sight, out of mind.”  ...right?

One day, we will realize that this place we call home has always been perfect. It’s just too bad that by the time this day comes, it will be too late to do anything about it.

This planet has always had what we needed, in just the right amounts. It is the biggest example of perfection. Tampering with things that we have no business tampering with only creates a domino effect of problems that trickle down through each and every organism & habitiat. One day, we will see that curiosity should have limits, and that changing nature to accomodate our selfish needs has never, and will never be the ultimate way to survive. We are not evolving. Our ego’s are simply growing to a size so large that we are incapable of tuning into the concern for any life-because our definition of “having a life” has changed. We live in an alternate reality now, trapped in cyber space. We don’t see what we are doing because we choose not to.  We’ve become wrecking ball wielding scientists, driven by money, materialistic satisfactions and social gratification.

In all, my point here is that stuffing our garbage in the ocean and under rock is the equivalent to shoving your dirty laundry under your bed. It will suffice for a while, but in the end you are going to be standing naked in a discusting, stinky, house.

Reply to this comment

By Stephanie Bedsaul (Ponte Vedra Beach/Florida)
on September 25th, 2012

http://www.fas.org/sgp/crs/misc/R42532.pdf

Reply to this comment

By Chris (CS TX 77845)
on September 25th, 2012

Ok, do you realize that all of the limestone in the entire world is carbon dioxide fixed into calcium carbonate by shell fish from millions of years ago?  This carbon dioxide was once in the atmosphere.  It goes into the ocean and the litte creatures turn it into calcium carbonate to make their shells.  More carbon dioxide more shells.

I also wonder if you realize that about half of the carbon dioxide that is pumped into the atomosphere by human activity is from cooking this limestone to produce cement. Many of you environmental types never talk about that. I guess it’s much harder to demonize cement use than oil use. (Oil black and dirty :( Cement white and clean smile  However, think about it.  If we completely stopped using oil, coal, and natural gas, we could only cut our emmissions in half.  Unless we dismantle what we call civilization also.

In addition, the Oceans are basic, not acidic.  There is a bit of semantic lying going on when people talk about ocean “acidification”  It’s presented like if you put your foot in the seawater on the shore it might dissolve.  There is no study, no proof what-so-ever for the claim that a drop in the PH of the ocean from a little basic to a little less basic will do anything at all harmful to any organism.

Someday I dream of a world where people will discuss the science of all of this rather than the politics.  And what I mean by science is demnostrable, reproducible, scientific work.  Not speculation based on projections of models that have been proven to not work time and time again.

Come on guys wake up.

Reply to this comment

By Brandon Postma (Saint Ignace)
on September 25th, 2012

This article looks more slanted toward alarmist than factual.  Some important information has been left out. 
Is the ocean acid now?  No, actually its a base (source:  Wikipedia), and it will take 500 years with higher levels of CO2 than we have now to neutralize the ocean.
A neutral ocean would not be any danger to shellfish.  Ocean PH is currently above 8, and shellfish are not affected until PH approaches 6. (source:  DNR)
Another 500 years would be required to make the ocean acidic to the levels affecting shellfish.  (source:  Wikipedia)
Warmer more neutral oceans produce more algae which convert CO2 to oxygen through photosynthesis.  (wikipedia)

Micrasterias algae is acidiophilic, and prefers an acid environment, it also eats CO2. (http://www.usc.edu/CSSF/History/2005/Projects/J1325.pdf)

The combination of ocean warming and neutralizing or acidifying the ocean will likely decrease the amount of CO2 through Algea growth and resist the changes described in the article above.  Equilibrium will likely occur at some pre-catastrophic point.

Reply to this comment

Name (required):
Email (required):
City/State/Zip:
Enter the word "climate" in the box below:

[+] View our comment guidelines.

Please note: Comment moderation is enabled. Your comment will not appear until reviewed by Climate Central staff. Thank you for your patience.