In honor of World Oceans Day, Discovery T.V.'s Planet Green released the trailer of NRDC's new documentary on ocean acidification today (world premiere will air on Discovery Planet Green in August).
The story of ocean acidification is especially appropriate for World Oceans Day because it is a cautionary tale of how the oceans often suffer from our terrestrial bias, the 'out of sight - out of mind' phenomenon, and the very real challenges of ocean science and its chronic underfunding.
For decades we have heard much about how rising atmospheric CO2 concentrations is causing global warming. However, carbon dioxide pollution is having a second effect of making the oceans more acidic (30% more acidic so far - to be exact). The truth is the CO2 problem is more faceted than scientists first led us to believe.
The process of ocean acidification is simple. The excess carbon dioxide from the burning of fossil fuels is not only stored in the atmosphere, it is also stored in the oceans (in fact, approximately ¼ of it -so far 500 billions tons - goes into the sea). As carbon dioxide reacts with ocean water, it forms a weak acid, carbonic acid.
This increasing acidity challenges ocean life on a few fronts. First, it reduces the availability of carbonate - a building block of sea shells. This results in slower growth rates and weaker shells in shelled organisms. If acidity goes high enough, shells literally dissolve, making the ocean uninhabitable to some creatures. This is a big deal because tens of thousands of marine species have carbonate shells or skeletons (not just our favorite seafood). Therefore the effects have implication for marine food webs. Second, increased acidity poses a physiological challenge to ocean life generally (i.e., even to animals without shells), making it more difficult for organisms to breathe and therefore carry out the daily activities necessary for survival.
It is clear that ocean chemistry is being altered on a scale not seen for tens of millions of years, and will likely present profound challenges to many forms of marine life in the coming decades. Ocean acidification is a global challenge on par with climate change.
So why are we just, now, learning about it?
The answer to that question differs depending on who you are talking to.
In actualilty the very scientists who alerted us to the phenomenon of global warming were well aware that a large proportion of the fossil fuel CO2 was going into the world's oceans. In their 1957 paper on the green-house effect, Revelle and Seuss discuss the beneficial aspects of this phenomenon from the perspective of global warming. By removing CO2 from the atmosphere the oceans moderate the green-house effect.
While scientists were aware of this 'service' that the oceans were providing, they seemed less concerned about its implications for ocean chemistry and biology.
There are numerous explanations for this blind-spot:
- 'Seeing is believing' and it was considerably more difficult to measure the fossil-fuel CO2 signal in the ocean compared to the atmosphere. As a consequence, there was no 'Keeling' curve for the oceans.
- Similarly, measurements of ocean pH sufficiently accurate to detect the changes in pH resulting from fossil-fuel emissions were difficult. It was not until the past 10-15 years that scientists were able to measure that the oceans had already undergone large changes in pH since pre-industrial times. Even now, there are very few 'time series' (or repeated measurements at specified locations) showing changes in ocean pH over time.
- Few scientists imagined that fossil-fuel production would be as rapid as it was. Even initial 'worst-case scenario' projections of fossil-fuel consumption were overly optimistic.
- Marine biologists did not realize that many marine species were sensitive to small changes in ocean pH. Many shelled creatures are negatively impacted much before ocean acidity reaches levels of shell dissolution. An entire science is now burgeoning in this area.
In short, largely because of the challenges presented by ocean sciences (high variability in the ocean environment, lack of permanent monitoring stations, increased cost of sampling and observation, and difficulty in rearing organisms) and its chronic lack of funding, a global - and profoundly important - phenomenon managed to slip by, largely unrecognized for decades.
Acid Test, the movie, aims to raise people's awareness of this phenomenon and warn people of its threat to ocean life. The film delivers two clear messages: now is the time for rapid reductions in fossil fuel consumption and we can no longer continue to take ocean health for granted. Establishing a national (and ultimately global) ocean monitoring system, which can measure important indicators like pH, is a necessary first step to improving ocean health.