We had to travel to space to fully realise the Earth is mostly ocean – a vast blue seascape swirling around continents. Nevertheless, we have largely continued to disregard the sea. Even those lucky to live near it rarely know more than the ocean’s shallow coastal fringe where it meets the land. And if the ocean makes headlines, it is often because we still exploit and pollute it.
In Blue Machine, British physical oceanographer and television presenter Helen Czerski introduces an ocean that is at the heart of our planet’s energy system. The term machine is not entirely metaphorical. With the passion of someone drawn to oceanography by the sheer awe of the ocean’s power, Czerski describes it as our liquid battery, with an enormous capacity to store heat energy, and a life-support engine, responsible for producing half of the oxygen we breathe.
This is an exceptionally readable book, thanks to Czerski’s skill in making unexpected connections between ocean physics, culture and history – such as when the first comprehensive ocean wave models were used to determine that June 6, 1944, was the best, or rather least dangerous, date for the D-Day landings in Normandy because they correctly predicted huge waves a day earlier that “could have caused one of the greatest wartime disasters for the Allies”.
Then there’s the journey of the Fram, the three-masted schooner that carried Norwegian explorer Fridtjof Nansen and his crew across the Arctic Ocean for three years from 1893. Built to explore Arctic sea ice not by breaking through it but by surrendering to it, the Fram was deliberately allowed to freeze into the ice to move at glacial speed with the transpolar current past the North Pole.
The history of human exploration provides Czerski with one avenue to spark interest on oceanography. To convey the importance of a healthy marine world, she weaves in stories about the exploits and survival strategies of sea wildlife.
There’s the weeping leatherback turtle, which cries litres of viscous tears to rid itself of the salt from its diet of jellyfish, aka “small bucketfuls of ocean masquerading as life”. There’s the tiny sea snail that evolved to float on bubble rafts to lift off the sea floor and reach the all-you-can-eat buffet at the surface. And there are stories that illustrate effectively how closely patterns of civilisation match patterns of the ocean, including one about guano, or seabird poo. The term goes back to the ancient Quechua word for fertiliser, because the Inca treasured a cold, nutrient-rich current off the South American west coast that supports an abundance of fish and nourishes seabirds. The birds left piles of the agricultural “white gold” and, eventually, set off an export industry centuries later when the US passed an act to take possession of guano islands in one of the country’s first attempts at imperialism.
Even the most committed landlubbers cannot escape the ocean’s influence. We all feel its power through weather. And this is what makes Czerski’s book particularly timely as we come to realise the ocean’s many invisible services are not without limits, including those that buffer us from the worst climate swings by taking up more than 90% of the excess heat we’re pumping out by burning fossil fuels.
Czerski is a persuasive and entertaining writer. She manages to wrangle complex physics into compelling analogies as she builds her case to advocate that we must care about the ocean. But the most gripping passages are when she’s face to face with the ocean’s power herself, paddling a waka ama from Hawai’i’s Big Island to Maui, feeling the physical energy of the surf and the raw exhilaration of being part of nature, rather than fighting or exploiting it.
Astronauts may experience the humbling emotions of watching our planet from afar. Oceanographers don’t get an overview of the vastness of the ocean depths, but Czerski rejects the notion that we know and care more about the Moon than the colossal expanse of the deep sea. The Moon is a dead rock, she writes, while the ocean teems with life and regulates the circulatory systems of our world. “We’re actually tiny ants living on the shores of this great blue fluid mechanism, completely dependent on its output.”
Blue Machine: How the Ocean Shapes Our World, by Helen Czerski (Torva, $40)