As the ocean goes, so go we

kw: book reviews, nonfiction, oceanography, polemics

Dr. Earle in her element.

We know more about the moon or Mars than we do about the oceans that sustain us. That ignorance could well prove fatal, perhaps to the human species, and probably at least to our civilization. Do we really want to avoid becoming again "just" the most intelligent of the apes, living like high-class chimpanzees among the ruins of a civilization we can no longer sustain? Then we need to know much, much more about the oceans and how to care for them. Having gained the power to destroy, it is incumbent on us to use that power to sustain. This is the message I get from The World is Blue: How Our Fate and the Ocean's Are One by Sylvia A. Earle, Explorer-in-Residence for the National Geographic Society.

This is not a book one reads for enjoyment (The Ocean: An Illustrated Atlas, published last year, is much better for that). No, this book is a thorough survey of the ways our vision of Ocean as unlimited and infinitely resilient have led us to push the very real limits to the breaking point, in a very short time. Firstly, the human race has extincted a few species of whale, porpoise and seal, and driven nearly all the rest to populations no more than one-tenth of their previous levels. We have also done so with species after species of fish, both directly for those fish as food or "products", and indirectly as "bycatch" when the target is shrimp or other shellfish. Though there is no chapter on reptiles, every species of large sea turtle is also endangered. Finally, the seas are a dumping ground, to the point that huge portions of the central Pacific, Atlantic and other ocean gyres are filled with tiny plastic bits that outweigh all biomass by a factor of six or seven.

The oceans support the air we breathe. We make much of the forests and grasslands as producers of oxygen. Phytoplankton in the oceans produce 70% or more of all oxygen. At the very least, using the ocean for a garbage dump has begun to cut into their numbers. Is that what we want? On a personal note, I wonder when it will become a worldwide capital offense to spill one's trash at sea? Sure, it is expensive to pump out a ship's bilge into a holding tank, or to carry all trash back to port, but one day we will see it is cheaper than the alternative.

In an appendix, a list and two maps show protected areas of the sea. The first map shows the "no fishing" zones: almost invisible. The second shows "sanctuaries" and other areas of all levels of protection, which amount to 0.8% (1/125th) of the total ocean surface, and much, much less a proportion of its total mass. Many pages of the book are devoted to narratives of the political and diplomatic grunt work that have been necessary to achieve this. How much protection will be required before properly sustainable populations of whales, codfish, oysters and all other depleted species can be restored? One stated goal is to totally protect the waters beneath 30% of all the oceans. At the rate we are going, there is some chance this goal could be reached before 2100 A.D. But at the rate the current damage is growing, there may be little to save by then.

Though there is a section on global warming, this is less an oceanic danger than a terrestrial one. I occupy a middle-ground position in the climate debate, but I am no "denier". It is likely, in my view, that global temperatures over the next 100 years will be about 2°C (~4°F) higher than they would be without our added greenhouse gas production. While I don't expect all the dire consequences on land that Al Gore threatens, I do expect some. I believe we can adapt, but there are two consequences at least that we cannot avoid.

First, a two-degree warming that penetrates to ocean depths (this takes a long time) will cause thermal expansion of the water, making the ocean one or two meters deeper. Bye-bye Maldives. These and a few other oceanic islands will be 50%-90% inundated, compared to today.

Secondly, extra CO₂ increases oceanic acidity. This hinders the ability of shelled creatures to make their shells. Note, however, that there are huge deposits of shell and coral fossils that were produced when the atmospheric CO₂ level was four to eight times what it is today. The problem will be with how fast this happens. Geochemical shifts in the past took tens of thousands of years to occur. This one is a century old, and will take no more than another century to unfold. We are in the midst of a great evolutionary experiment, to see just how fast the clams and corals can evolve into species that do well with more carbonic acid in the ocean. They will eventually adapt, but we may not be there to see it.

And that is the message. What is the real danger here? What are we really doing? A million years from now, how many individual Homo sapiens will remain on Earth? Will there be more than one billion? That is unlikely. The rate at which we are eating up the fish and sea mammals, as our ancestors ate up the mammoths and saber-tooth cats (we ate more of them than they ate of ours), indicates that earth's true carrying capacity for 80-kg naked apes is about 100 million. What we do not accomplish with social and political means, nature will accomplish by means much less pleasant.

I use the label "polemics" in my categorization. That is not necessarily a negative word. Many of the Scripture books are polemical writing (whether Christian or not). Dr. Earle's book happens to be a polemic that I agree with.