About 5,000 years ago, a millennium after the emergence of civilization in Mesopotamia, legend has it that Gilgamesh, king of the city-state of Uruk on the lower Euphrates River, traveled to a distant land now known as Lebanon, where he defeated the forest god Humbaba to capture the prized Lebanese cedar. This feat is recorded in the Epic of Gilgamesh, the earliest story recorded in cuneiform writing. Before that time, during the previous 1,000 years of Mesopotamian civilization, the forests of the Tigris and Euphrates valleys had been completely denuded.¹ Gilgamesh had embarked on his legendary plunder of Lebanon to acquire the timber needed to support the prosperity of Mesopotamia. This same magnificent tree played a role in Egyptian civilization as well. When the forests of the Nile valley began to disappear, the ancient Egyptians began to covet Lebanese cedar. The Boat of Cheops discovered in the Pyramid of Khufu was made of this same wood. The same evidence of deforestation has also been found in the Yellow River of China. The rise and fall of ancient civilizations was consistently accompanied by the progressive devastation of surrounding forests.

　

The first seafaring people to appear in history were the ancient Phoenicians, who used Lebanese cedar to make their ships. The Phoenicians began plying the Mediterranean in their cedar ships about the time of the events of the Epic of Gilgamesh; by about 1200 BC, these early manners had passed through the Straits of Gibraltar, and even (it is believed) rounded the west coast of Africa and the Cape of Good Hope to reach the Arabian Sea.

　

The stately cedar forests that once carpeted Lebanon were so recklessly overcut that today they survive only as a sad remnant deep in the remote mountains of that country. When the forests were laid waste, soil erosion began, causing the ruination of once-fertile agricultural land. With the loss of forests in the mountains, nutrients from the land ceased to find their way to the sea, causing life to disappear there as well.

　

Gradually the center of civilization shifted westward, from Mesopotamia to the eastern Mediterranean. Already, however, the mountains and seas of these regions had withered under the influence of Mesopotamia and Egypt.² This is why the ancient Greeks had to vie for supremacy on the seas; no longer able to feed themselves, they were obliged to import their food supplies. The first sea battle ever recorded, the Battle of Salamis (480 BC), was fought between Persia, a continental Asian power, and Athens, which was motivated by a need to secure the sea lanes of the eastern Mediterranean.

　

　

The first hominids began breaking away from the rest of the primate family in Africa about 4.4 million years ago. Humanity evolved as it traveled, eventually taking to the seas in its search for prosperity and stability. Tribes that moved about on the sea were able to develop economically through trade, creating prosperous seafaring nations. Unfortunately this same process led to war and the disintegration of the environment. Time and again, the rise and fall of civilizations throughout history reveals that the ruination of peace and the environment drove a process of unsustainable development.

　

A change is underway among the penguin populations of Antarctica. The population of Adelie penguins, which thrive on ice, is dwindling, while the chinstrap penguin, which is at home in the sea, is increasing in number, according to recent surveys³-a further sign that the southern ice cap is receding.

　

The earth's seas came into existence 4.5 billion years ago. The churning of the seas over 500 million years eventually brought life to the erstwhile barren shores. The ozone layer that protects us today was formed by the photosynthesis of the earliest bacteria, creating a suitable environment for life on earth to flourish as never before. In the seas, phytoplankton absorbed carbon dioxide through photosynthesis and provided sustenance for zooplankton. In turn, small fish emerged to consume the zooplankton and were themselves food for larger fish. It is now believed that phytoplankton absorb as much carbon dioxide as all of the flora on land, stabilizing the earth's climate and preserving the balance of life in the seas. In recent years, however, a shift has been observed in the oceans plankton population, with enormous implications for the climate and the marine food chain.⁴ For example, unusual blooms of coccolithophorids, which release carbon dioxide, have been indicated. Red tides and unusual blooms of algae are thought to be caused by the warming of the oceans, as well as an increase in nutritive-salt loading in coastal areas caused by runoff of agricultural fertilizers. Much about plankton remains poorly understood, and some researchers are of the opinion that more systematic research is need.⁵ Such systematic study is vital, as plankton are a cornerstone of the environmental mechanisms of the oceans.

　

If we calculate the progress of global warming according to their relationship with greenhouse gases, the concentration of carbon dioxide in the atmosphere, which is currently about 350ppm, could rise too 700ppm by 2100. This could raise the temperature of the earth's atmosphere anywhere between 1℃ and 4.5℃.⁶ To put this in perspective, over the past 100 years the atmosphere has risen in temperature between 0.3℃ and 0.6℃, which has already been sufficient to raise the surface of the sea some 10-20cm. If global warming continues along current trends (that is, if carbon dioxide concentrations reach 700ppm a century from now), it is said that the polar ice caps will shrink so much that the seas will rise 50cm.⁷ A still more serious state of affairs, according to some observers, is the release of methane hydrate into the atmosphere. As the name suggests, methane hydrate is formed by the binding of methane to water molecules. Some 10 trillion metric tons of this substance is estimated to lie on the ocean floor, 500m and more below the surface. About 8,000 years ago, an eruption of 350 billion metric tons of methane hydrate occurred off the coast of Norway. This event corresponds to a period of global warming. If a large quantity of methane hydrate is similarly released into the atmosphere, global warming can be expected to accelerate alarmingly.

　

The Republic of the Maldives, an island nation in the Indian Ocean, has achieved splendid growth over the past decade. The number of public schools has leaped from a single facility to 50, while average life expectancy has risen 50%. Yet it is faced with an urgent and most extraordinary problem: Its national territory may soon completely disappear The Maldives consists of a necklace of some 1200 tiny islands with an average elevation of just 1.5m. If the sea level continues to rise on present trends, the entire archipelago will sink out of sight. For the Maldives, stabilizing the global environment is a matter of national security. The global issue of environmental degradation, which transcends national boundaries, has become a similarly international threat to security. Several nations of the South Pacific are also faced with this problem. For example, Tuvalu, which has the same average elevation of 1.5m that the Maldives does, is trying to arrange the transfer of the country's entire population of 11,000 souls to Australia and New Zealand.⁸ The people of Tuvalu have become a nation of environmental refugees.

　

A deep ocean current originating in the waters off Greenland in the North Atlantic, 3000m below the surface, has been traversing the oceans for about two thousand years. This current maintains a constant temperature of 15∞C recently, however, runoff from the melting Arctic ice cap has reduced the salinity of the water, reducing the deep current's ability to sink. Recent measurements show that it has risen as high as 1000m below the surface.⁹ This is an ominous development, as it is impossible to predict what climate changes the shift may foster.

　

Roughly 71% of the earth's surface is covered by waters, which means, simply put, that the earth's environment is 71% controlled by the oceans. Rather than call this planet "the Earth," named for its terra firma, it would be fairer to call it "the Blue Planet." A synergism between rising ocean temperatures and rising atmospheric temperatures is accelerating both, causing an outward flow of polar ice that forces an enormous impact on marine biosystems. Air pollution is a central factor in both ocean warming and atmospheric warming, conspiring with overfishing to deplete the precious resources of the seas. Fish stocks are declining in all of the world's major fishing grounds today because of these twin factors, as will be discussed in greater detail later. According to the 2002 Resource Evaluation announced by Japan's Fisheries Agency, stocks of sardine and mackerel are rapidly dwindling in the nation's adjoining waters. The decline is especially stark in the Sea of Japan, where catches have shrunk from a peak of 600,000t in 1989 to 1400t in 2001. The total remaining stocks of these fish is now estimated at no more than 2300t. Catches in the Pacific Ocean are similarly less than 1% of their levels in bumper years. Essentially these stocks are already exhausted, devastated by overfishing and environmental changes such as global warming.¹⁰

　

If the destruction of the environment and the fishing stocks continues unabated, the "silent spring"¹¹ in which the birds no longer sing will be preceded by the "silent seas." The stabilization of the marine environment and protection of the seas' resources the most pressing issues for the security of the human race.