When Georg Franzius, a German hydraulic engineer, traveled northward along the Chinese coast in 1897 to settlements scattered around Kiaotschou Bay (today Jiaozhou Bay), he was not particularly excited by what he saw. Although Qingdao, the name of the area he was heading to, translated as “green island,” there was little green. The region had only a thin layer of soil to support vegetation and, although it was not densely populated, its residents had overexploited the natural tree cover for fuel. In his report to the German government, Franzius described the vegetation of the site as “bleak” and “desolate”, but when he was gazing at the seascape, he did recognize the sublime beauty of how the dark blue ocean contrasts with the reddish-brown mountains. Meanwhile, he noted the bay’s potential to be transformed from a site of agriculture and fishing into a new hub for maritime trade, connecting the hinterlands and markets of China with Germany and the rest of the world.

The next year, German colonists started constructing a port on this strange site, envisioning a city with a comprehensively planned environment. As an industrial power, the newcomers anticipated building infrastructure such as shipyards, textile factories, and even a brewery in the colony, as well as a railroad to connect their new city with the resources of northern China. Yet, they wanted more.

Despite Qingdao’s poor vegetation, a deficiency they hoped to fix in a decade or two, they brought with them a century’s worth of European Romanticism. Seeing the area through this lens, they eventually discovered its stunning landscapes—its long winding coastline, rugged rocky shore, and wide flat beaches. The rolling hills would cause headaches for their engineers, but they would also inspire architects and builders. Equally important, the sea, beaches, mountains, and mild climate offered recreational possibilities for the modern consumer-oriented society that Germany was becoming. Encouraged by those attractions, the colonizers, who came from a land of dense forests, dreamed about building a Mediterranean-style city with Far Eastern characteristics.

Such a city was alien to the Chinese who had worked over thousands of years to build a successful agricultural society. Their aesthetic traditions had long celebrated lakes, mountains, and rivers as ideal forms of beauty. But the sea had been too remote and mysterious to be loved and embraced. The coast had been marginal to Chinese ideals, while those who relied on the sea for a living were a marginalized people. There were a few port cities, like Quanzhou and Ningbo, but they functioned merely as commercial sites for trading with the rest of Asia, while mainstream China paid little attention to the sea or shore.

The Europeans had likewise discovered little to attract them in the ocean or seaside until the late eighteenth century. For centuries, with few exceptions, the sea symbolized danger, terror, fear, and catastrophe. Such negative feelings haunted the Europeans for a long time, even those living around the Mediterranean Sea and in island nations like Britain, who had grown more comfortable with the sea, at least more so than the continental nations. After the Enlightenment, modern science and Romanticism changed that mentality. Europeans began to find a promise of health, beauty, and recreation in the ocean, and built new resorts by its side in Britain, France, Italy, and Greece. The Germans, with fewer coastal areas of their own, absorbed this new understanding of the sea. And now here they were at the eastern end of the Eurasian continent, on the rim of the Pacific Ocean, undertaking to create a new city by the sea.

Even today, the Pacific Ocean is a recent phenomenon in many people’s eyes. For a long time, it was too wide and too deep for even the most imaginative to know and navigate. It defied any empire’s reach or any individual’s ambition. Not many people found interest in the seaside or had the technology to exploit the wealth lying in the deep. There had been Indigenous peoples venturing out onto the ocean, driven by various reasons, such as the quest for food or power. Some of them like Polynesians even crossed parts of the ocean and founded new settlements in Australia, Hawaii, and New Zealand, but they became isolated from the rest of the world along with their knowledge about the ocean. For most people living on both sides of the Pacific Ocean, they preferred to make a living on a plain along a big river that was easier to understand and control. Therefore, much of the rim of this ocean had been left more or less wild except for a few scattered fishing villages living in rhythm with the waters offshore.

It was only in the late nineteenth century that a process of intensified discovery and urbanization of the Pacific Rim began, with Qingdao becoming a leading example of a coastal settlement. What had been a handful of fishing villages became a thoroughly modern city in the early twentieth century, and by the twenty-first was an ocean-facing metropolis with more than ten million inhabitants, six million of them living in the city proper—a process that occurred within a mere 120 years.

Qingdao was not an old-style port from which a famous admiral like Zheng would sail to Asian and African countries to demonstrate the power and benevolence of the great Chinese Empire. Nor was the new Qingdao a quaint seaside resort with antique ruins, supplying good air and romantic scenery. It grew up as both a port and a modern resort. From its beginning, it transformed into a “cosmopolis”—a planetary city interacting with the ocean and other places around the Earth. It was based on the conquest of nature, exuding great confidence in technology, but also promoting a modern appreciation of the natural world that embraces the wildness, grandeur, and tranquility of the nonhuman. Since the earliest days of German colonization, people have come to Qingdao from many countries to consume nature in terms of health, recreation, and even fashion, all the while exploiting and degrading the environment.

The Chinese shoreline city was not alone in this age of coastal settlement. On the other side of the Pacific, we find its counterpart in the United States—in Los Angeles, the City of Angels. The ocean that connects Qingdao and Los Angeles is the biggest on earth, and for a long time it was too wide for travelers to cross rapidly and compare their societies, as they had done so often with the Atlantic. But since the discovery of gold in California in the 1840s, there has been a growing number of crossings, not only through immigration, trade, and exchange of knowledge and technologies, but also through people coming to share a common environment made up of many species, ocean currents, and deep tectonic movements.

As countries, it may be that China is old while the United States is young, making comparisons more difficult. Yet, when we look at these two cities, Los Angeles and Qingdao, we find that both grew up about the same time (although LA began as a city more than fifty years before Qingdao). For much of their precolonial histories, the two areas supported a limited population, who subsisted mainly on the food they acquired from the local sea and shore and who lived in sync with the rhythms of nature, although there was some trade between them and other regions. Neither of them grew up along major rivers flowing from a deep interior. Before railroads replaced rivers, neither settlement could expect to become a big hub in an inland or transoceanic network. Both were surrounded by hills and plains, and both were short of a large, reliable water supply and thus grew up thirsty for water from elsewhere. Most importantly, both were on the rim of the Pacific Ocean, and that ocean became the leading reason for their existence.

In terms of the usual historical criteria, these two cities had little in common, other than the fact that both began as colonies of European imperialism: Qingdao was colonized by the Germans and LA by the Spanish and Americans. The American coastal metropolis was in part the product of a free, competitive, individualistic market economy. Qingdao, in contrast, developed under more rigid controls and planning, from the German era to Japanese ownership after Germany’s retreat from the Far East in 1914, to the Republic of China’s period of governance and today’s rule by the People’s Republic of China. Even in its precolonial past, Qingdao’s small fishing villages belonged to an empire centered a long way off, compared to the Native Americans living in the Los Angeles basin, scattered in small, competing bands that answered to no outside authority. The two cities are not, therefore, alike in their economies or politics.

These important contrasts, however, make comparing the two cities’ history more, not less, interesting: Why did two cities, radically different in their cultural origins, come to resemble each other in size, cityscape, and perhaps even in temperament? Why has each grown from inconspicuous beginnings to a giant metropolis over the past century, and why have they attracted millions of inhabitants?

The Pacific Ocean unites them. Trading ports and navy bases are important functions for both cities, but the ocean serves as much more than a vehicle for commodities and warfare, or as a depot for natural resources like fish, oil, minerals, and energy or commodities like hay and rice, refrigerators, and computer chips. Both cities are complex human-reconstructed ecosystems, comprising geology, climate, ocean currents, fauna, flora, microbes, and people. But when a peninsula around Jiaozhou Bay became the city of Qingdao, and when a Tongva village named Yang-na (meaning “poison oak place”) became Los Angeles, when settlers from Germany, Japan, China, Spain, Mexico, and the midwestern US arrived and began building their city by the sea, they created an invisible bond across the Pacific Ocean.

Undoubtedly, many people have gone to these cities seeking jobs. But that alone has not determined the tides of migration. Newcomers wanted lives filled with sunshine, surfing, beaches, and mountains, facing outward to the world, and yet close to nature. Does that search simply echo Western Romanticism or traditional Chinese ideals? Or does it go beyond culture to reflect some universal need for the ocean?

Ancient people shunned the ocean precisely because it seemed beyond their control. That insecurity and uncertainty stopped them from settling in large numbers close to the ocean so that they could observe its changes and enjoy its beauty. Modern technology has made a life on the edge of the sea possible; it has helped dissipate old fears and provide new security. Twentieth-century residents managed to reclaim parts of the sea to make new land and to withstand the force of typhoons, hurricanes, earthquakes, droughts, and many other dangers that come from living along the Pacific. Whether real or illusionary, these technological means have encouraged a feeling on both shores that living there is now safe.

There is a distinctly modern paradox in both Qingdao and Los Angeles. It goes beyond the antinomies created by colonial imperialism—the benefits and costs that imperial power brings. At the core of the novel contradiction lies a tension between zealous celebration of the ocean and the high risks that people must encounter to live by its side. Living by the sea has come to stand for a more prosperous, glamorous life, yet that life brings new environmental vulnerability. This vulnerability comes from the fact that in an age of human-made climate change, which is causing glaciers to melt and seas to rise by centimeters or even by meters, any city located by any sea is now among the most dangerous places on earth.

In China, coastal people are vulnerable to climate change not only in Qingdao, but also in Dalian, Tianjin, Shanghai, Hong Kong, and Guangzhou, all prominent shoreline cities. In the United States, 127 million people live in coastal counties. And yet migration toward seaside living continues in the United States and China. The cities of LA and Qingdao continue to grow despite scientists’ warnings that, in future, seas may rise and invade agricultural fields, densely packed streets, homes, and industries, and pound them with violent storms that the warming waters spark. Thus, the modern desire to live close to the sea brings a kind of vulnerability and risk-taking that is new to history.

We need to think about urban environmental history in a more ocean-conscious way. For here on the edge of the sea much of human experience is rewritten, and we can no longer think about cities without thinking about the planet around them.