World Oceans: Swimming Against the Tide

Sermon Audio: 

Peter Shelley
April 23, 2017

Good morning. It is a pleasure to be here and I want to thank Pat Skibbee and the members of the Climate Action Project for inviting me to share my thoughts with you and the work they do for all of us.

The title of my message today is Our Oceans: Swimming against the Tide.

I am passionate about the ocean. Full disclosure: I grew up on a dairy farm in Pennsylvania, hours from the ocean. My early water world was confined to a farm pond and a stream that separated our farm from the neighbor’s. My earliest ocean memories were Jacques Cousteau’s 1950’s documentary The Silent World and the much more crass television scuba adventures of Lloyd Bridges in the early series Sea Hunt.


As best I can tell, no one knows how old the Earth’s oceans are or exactly how they formed. It seems that it is most likely that oceans came into existence on earth some 4 billion years ago when the planet’s surface temperatures finally dropped below the boiling point of water and the planet’s cloud vapors liquefied.

The first complex life as we know it on earth formed in the earliest ocean as the microbe cyanobacteria—a form of blue-green algae—about 2.5 billion years ago. This was the first organic life capable of photosynthesis and the most of the oxygen in the early planet’s atmosphere came from algal photosynthesis.

The divisions of continents and oceans as we know them today happened from tectonic plate movements over a period from about 250 million years ago to 50 million years when present-day India collided with the Asian continent.

The ocean and the atmosphere are in constant communication: exchanging heat, salt, water and energy--back-and-forth. Add the hydrologic cycle that connects the ocean, the atmosphere, and the land and we have the planetary conditions that allow us all to be seated here today as the planet’s water cycles from gaseous phases to liquid phrases to solid phases.

It is no accident that the first planetary attribute scientists seek in space explorations is the presence of water. Without water, there is no life, at least no organic life as we know it.

  • 70% of the planet is covered by the oceans
  • 98% of the planet’s water is in the oceans
  • 50% of the oxygen we breath—every other breath--comes from the process of planktonic photosynthesis in the ocean
  • Phytoplankton in the ocean constitute approximately ½ of the organic matter on Earth
  • The oceans absorb some 25%-30% of the carbon in the atmosphere in the form of CO2 as part of the planetary carbon cycle.
  • The ocean stores 16 times more carbon than the terrestrial world and 60 times more carbon than the pre-industrial atmosphere did.
  • Empirical data indicates that the ocean, the land, and the atmosphere were substantially in equilibrium with each other before the industrial revolution.

Carbon is the element of life. The human body structure is based on carbon. CO2 fuels life through the photosynthesis in the ocean and on land, which produces oxygen and energy-rich molecules of sugars and starches


From the fossil records, we do know that the ocean’s sea levels have not always been where they are today.

In the Ice Age that ended 20,000 years ago, the Laurentide Ice Sheet covered much of North America, in some places over 2 miles deep, depressing the land underneath several thousand feet in places and taking up much of the planet’s water.

Sea levels off New England 20,000 years ago were about 400’ lower than they are today and today’s underwater George’s Bank, the vast terminal moraine of that Ice Sheet stretching from Cape Cod almost to Nova Scotia was high and dry, inhabited with giant sloths and mastodons, whose bones are still sometimes found today by fishermen trawling the now submerged plateaus of the Bank.

The glaciers retreated from New England 13,000 or so years ago. As the vast glacier melted, sea levels in New England and elsewhere in the world rose some 400’ higher than today. Today, you can readily find the fossils of seashells on flanks of the Camden Hills in Maine. Unburdened again from the vast weight of the ice sheet, the land in New England slowly rebounded.

As the land and ocean once again reached rough equilibrium, we are left with this beautiful estuary and barrier beach that we call Newburyport and Plum Island.

The ocean is big. If you stand in the crashing surf line at Plum Island or sail far from land, the sensory experience in a word is “vastness.” That vastness has led humans since the beginning of time to think of the ocean and its resources as unlimited. Even as President Grant was creating the world’s first national park—Yellowstone--in the 1870’s, prominent British scientist Thomas Huxley—Darwin’s “bulldog”—was busy chastising his U.S. contemporaries who were proposing limits on fishing that that the ocean was so vast and abundant that "nothing we do seriously affects the number of fish."

Huxley, of course, was wrong. If you poured all the oceans into a sphere the size of the Earth, they would only fill about one-tenth of 1% of that vessel. Our oceans are vast but finite.


I want to shift now to us, to humans. The following thoughts come mainly from the Israeli historian Yuval Noah Harari.[1]

Evolving just 150,000 years ago, Homo sapiens at that time was just one of at least 5 human species co-existing on the planet. Located in East Africa, Homo sapiens--like all human species at the time--was a minor species on the planet, lacking in all significance.

In Harari’s words: “They were unimportant animals, minding their own business in a corner of Africa. Their impact on the world was small like the impact of jellyfish, woodpeckers, or bumblebees.”

Starting about 70,000 years ago, however, H. sapiens expanded out of Africa. At about the same time that the Laurentide Ice Sheet reached its maximum extent, some 25-30K years ago, Homo sapiens crossed the grassy land bridge between Siberia and Alaska, reaching New England some 14,000 years ago as the glacier retreated further.

Over the course of 50,000 years, H. sapiens wiped out most of the mega fauna--the large animals--on the planet substituting domesticated animals. They also accomplished, in Harari’s words, perhaps the most thorough ethnic cleansing on the planet, wiping out all the other human species.

In 150,000 short years, not even the bat of an eye in evolutionary times, Homo sapiens had changed the world’s ecosystem, vaulting from an insignificant ape huddled on the plains and woodlands of East Africa to the planet’s apex predator and foremost engineer.

No one should doubt or underestimate the significance of our species, H. sapiens, on the world we live in today.

Back to the oceans….

Humans have been putting carbon dioxide into the atmosphere and ocean at least since fire was domesticated. The industrial revolution, however, marked a break in the amount and rate of our carbon emissions into the atmosphere, both through fossil fuels that ran the modern industrial world and through evolving intense agriculture and land use practices.

While the planet has witnessed cataclysmic ecological events, such as the asteroid or volcanoes that killed off the dinosaurs and other species 65 million years ago, scientists have never before directly observed in real time the rates of change our planetary ecosystem currently experiences. Homo sapiens have never lived with such rates of change in the world around them. We have entered a new era: the anthropocene epoch.

Data from our oceans are a powerful barometer of this change and scientists have been directly observing these changes for some time: sea temperatures, sea levels, the pH of the ocean—that is, how acidic it is becoming--ice cover, and even plankton densities.

Because of our greater increased computational capacity and modern statistics, scientists now can distinguish the natural historic cycles of these sorts of data from the trends of post-industrial human-induced changes.

Sea levels are rising as the oceans heat and expand and the remaining glaciers sitting on land melt.

Ocean absorption of the increasing CO2 through the carbon cycle results in the pH levels of our oceans dropping, what is referred to as ocean acidification. A more acidic ocean interferes with the ability of a broad range of marine organisms from zooplankton to lobsters and scallops—the mainstay of the New England fishing economy—to form their shells by changing the saturation state in the ocean of the calcium carbonate minerals those animals use for that process. If acid levels become too high, ocean waters could actually dissolve these calcium carbonate structures through the reverse process by which they are presently built.

We do not have to look far to see some of these impacts. The Gulf of Maine, just beyond the Plum Island barrier beach, is heating faster that 99% of the water bodies on the planet, with the potential to dramatically change the Gulf”s suitability for the cold water species that have been here since recorded time.

The climate change impacts on plankton populations extend beyond acidification. One recent scientific paper calls the conclusion that increasing sea surface temperatures have led to an overall decline in global phytoplankton concentrations over the last century--“unequivocal.”

And some scientists worry—and it is just a worry at this time—that at some stage the changed oceanographic conditions and artic ice melt could result in the change or even the halting of what is popularly called the “Ocean Conveyor” that mixes the cold and water waters of the world around the planet and controls land temperatures. The warm tropical waters that travel northward off our coast in vast oceanic rivers before cooling and reversing course southward at the depths of the ocean are what determine the climate of much of northern Europe and England.

If those currents changed or stopped, the world, as we have always known it, would cease to exist. As I said, this is only a broad, abstract worry at this stage in science community at this time. But, to be sure, it has happened before in geologic time and no one exactly knows what the tipping point was then or what it might be today.


So, where do we go from here?

Back to Yuval Hurari for a moment: Harari argues that the one thing that differentiates Homo sapiens from all other species is not just that we are social and cooperate with each other in our human economy--whales and chimpanzees and many others do that--or that we are capable of organized behavior at the level of millions of individuals—ants and bees do that.

What is different about us, he contends, is that we are able to both “cooperate flexibly and in very large numbers.” No other species can do that and it is likely what gave Sapiens the edge over the other human species.

How do we do that? He concludes that it is our capacity for fictions, powerful stories that we are free to change rapidly as necessary. The world of Homo sapiens, he says, is built on fictional stories: money, corporations, nations, states, congregations, the importance of art and science—all fictions.

These are not natural things: you can’t smell them or taste them or even touch them but you also can’t deny their power. They are the stories that shape our world and its future

The question we must ask is: What is the story that gives my grandchildren and your grandchildren a future in this rapidly changing world we have created: the anthropocene epoch?

I have worked for many years on an atoll nation called Kiribati in the middle of the Pacific Ocean. Throughout much of their nation, the I-Kiribati people live, work, and socialize only a meter or so above the ocean. As the sea rises around them, creating what to most would be an existential crises, many there have a story in which they profoundly believe about the Biblical Flood and God’s covenant with Noah: “never again shall there be a flood to destroy the earth.” That is the story that animates their life.

That is not a story I believe in. The story I am going with and that I urge on you is that climate change is real and it will change virtually every aspect of our grandchildren’s lives. But I also believe that the ecological trends that threaten the world we know and that we will leave our children’s children are neither terminal nor inevitable. I believe we still have time to use these brains we have to rewrite the story about our relationship with the ocean and with the planet.

In that story, we will learn to live and even prosper without carbon-based fuels, reversing GHG emission rates—50% of the new power is already coming from renewables in the US.

With sufficient dedication, we will discover technologies that will draw carbon out of the atmosphere or allow other safe interventions with the natural carbon cycle. We hopefully will learn that the ocean’s resources are not infinite and restore health to our oceans so marine life can fare better under the stresses of climate change than they can today in a depleted condition.

Today as we sit here in this beautiful space surrounded by our friends during the week we celebrate the Earth, two things particularly strike me:

Right off our shores here, we--a species that is less than 150,000 years old--are close to permanently extinguishing the existence of the North Atlantic right whale, a species that is on the order of 25 million years old. Tangled in fishing gear or traumatized or killed by ship strikes, the right whale now seems doomed. That seems fundamentally wrong.

Second, we are, perhaps, at the most critical stage in our brief tenure here on earth. Yesterday, people around the country and planet organized the March for Science. What strange juncture have we come to as a species where it is necessary to organize an international march not to assert civil rights, not women’s rights, but the importance of the scientific method itself? I dare say that not since the persecution of Galileo Gallilei—more than 350 years ago-- has science and the scientific method been challenged in such ways. Now, when we need science more than we ever have.

I’d like to finish with some words about “Swimming against the Tide” penned by Harriet Beecher Stowe: “Never give up for that is just the place and time that the tide will turn.”


You and I and our offspring--Homo sapiens all--for better or worse are the stewards of this planet and the authors of our destiny. I pray that we will write a story with a happy ending.

[1] I highly recommend Harari’s book Sapiens for a remarkable story about how we came to be where and who we are. Most of the ideas in this section come directly from his fascinating theories.