Ships have always been the cheapest, fastest way to move cargo over long distances. Most of the world’s populations live in coastal areas, and on waterways, for this very reason. Shipping is the lifeblood of economic globalization.
Over 60,000 colossal ships crisscross ocean trade routes, burning over 2.2 billion barrels of heavy fuel oil annually. Heavy fuel oil is the residue from crude oil refining. This filthy fuel emits 1,800 times more sulfur into the air than diesel engines. The 16 largest ocean ships produce as much sulfur pollution as the entire global fleet of cars. Heavy fuel oil is the stuff that no one on land is allowed to burn. Ships contribute ~2.5% of global greenhouse gas emissions.
Ship pollution affects local weather. Thunderstorms above busy shipping lanes are much more intense.
Large marine mammals are regularly run over by trade ships. The noise of ocean vessels disrupts and shortens the lives of those sea creatures who are not more grievously abused.
The ballast water that ships carry and discharge at the next port of call does a wondrous job of transporting diverse zoos of biological specimens, including plants, animals, and a vast variety of microbes. Today’s cargo ships perform this function much more prodigiously than vessels in earlier ages. By dint of ferrying people for extended periods, cruise ships do their cargo brethren one better in generating nasty bilge which is dumped in the seas.
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Since glaciers and ice caps are masses of land-based frozen water, their melting and runoff into the oceans causes sea levels to rise. In contrast, because sea ice formed in the ocean and floats there, its loss would be relatively insignificant to sea-level rise. But sea ice loss does release greenhouse gases and pollutants stored in the ice.
Even without deglaciation or other melt, sea levels would rise simply from the waters becoming warmer. Warming invokes thermal expansion.
Because of limited comprehension and failure to include critical variables, current climate models have been poor predictors of atmospheric warming and sea level rise. Models have consistently underestimated what has occurred, and so fail to fully anticipate what is going to happen. For example, researchers were recently surprised at the extent of ice melt from below in the Antarctic.
Just over 3 million years ago, global surface temperature was 2 to 3 degrees centigrade warmer than in modern preindustrial times; a warming level likely sometime around the 2060s. The average sea level 3 million years ago was 16.2 meters higher than today.
The warmest period during the Pliocene was 4.4 million years ago, when temperatures were 4 degrees centigrade hotter than the preindustrial era; a level of hotness which will be reached by the end of this century. Sea levels then were 23.5 meters higher.
A conservative projection is that sea level will rise at least a further 2 meters by the end of the century. That level will flood coastal cities around the world, directly affecting over 300 million people (at current population levels). The likelihood is that the seas will be even higher at century’s end, as global warming accelerates. Climate models have consistently been shy in their estimates.
Sea level rise alone would be enough to disrupt economies around the world. But, of course, rising waters are only part of the disruption of the oceans. Warmer air and water work together to create more devasting tropical storms. This destructive gyre has already gathered pace and will accelerate further in coming years.
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The release of greenhouse gases and surface warming are the most obvious aspects of the world heating up. So far, the oceans have absorbed over 90% of the heat energy added to the world’s climate system. The oceans are the world’s largest natural carbon sink.
There is a balance between marine and atmospheric temperatures. Air temperatures can be expected to soar in the coming decades as the oceans release more of the heat that has been stored there. This is on top of the continuing rise in greenhouse gas emissions from man-made sources.
25% of the carbon dioxide pumped into the atmosphere ends up in the ocean. Through a series of chemical reactions, oceans acidify as they absorb CO2.
Since industrialization, the world’s oceans have become 30% more acidic. Marine pH continues its freefall. The oceans are now more acidic than they have been for over 2 million years.
Many organisms cannot stand the rising astringency. Among other effects, fish lose their sense of smell, greatly reducing their ability to survive.
Ocean oxygen levels are dropping around the world. Dead zones, where oxygen-breathing sea life cannot survive, are a growing problem.
Just as heatwaves induce wildfires on land, marine heatwaves are increasing in frequency and severity, destroying coral reefs, kelp forests, seagrass meadows, and other oceanic ecosystems in just weeks or months. Between 1987 and 2016, marine heatwaves jumped over 50% compared to the period of 1925 to 1954. As with the atmospheric hotting up that we associate with global warming, the oceans are heading toward a boil and acidity that cannot sustain life, even plankton.
Phytoplankton are the base of the marine food chain. Without plankton, the ocean food web does not exist.
A steady decline in phytoplankton numbers in the early 20th century accelerated mid-century. 1950–2010, global microalgae populations dropped 40%. The warming is especially affecting tropical plankton, decreasing their diversity as species go extinct.
As waters warm, marine pathogens proliferate. Vibrio, a bacteria that infects shellfish such as oysters, already sickens 80,000 Americans each year.
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Coral provide the base for reefs which may extend for many kilometers. These reefs are critical buffers preventing shoreline erosion.
Coral reefs are mainly in shallow tropical and near-tropical seas offering tepid temperature waters. Reefs are sensitive to light, temperature, and water acidity.
Coral reefs are the rainforests of the sea, forming some of the most diverse ecosystems on Earth. Though they occupy less than 0.1% of the world’s ocean surface, coral reefs are home to 25% of all marine diversity. That makes coral one of the most important keystone species on the planet. Many of our societies rely upon the seafood bounty that need coral reefs to survive.
Coral reefs are a major player in the biosphere: helping regulate global temperature. Making calcified shells absorbs carbon dioxide, thus acting as a modest sink for this greenhouse gas.
Before the 1980s, large-scale coral die-offs were virtually unheard-of. Since then, coral bleaching has happened so frequently that reefs are unable to recover.
The Great Barrier Reef off the eastern coast of Australia is the world’s largest coral reef system. It took millions of years for the Great Barrier Reef to grow to its 20th-century size. Then human pollution began to take its terrible toll. By 2019, nearly 90% of the reef had been decimated. The entire Great Barrier Reef will be dead by 2030.
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Over half of the global human population rely upon seafood as part of their diet. The seafood platter has been thinning from the early 20th century.
The fishing industry worldwide has done its utmost to destroy its own business. Since 1950, over a quarter of the world’s fisheries have collapsed from overfishing; a trend that began in the late 19th century.
The decimation of ocean ecosystems has been a government project. After the 2nd World War, the United States used fishing rights and fisheries technology as a geopolitical tool. All around the world, America engendered overfishing. Sensing the political struggle, other countries responded in kind.
90% of Earth’s once-abundant fisheries are either fully exploited or facing collapse. Oceanic ecology has been unbalanced worldwide.
Yet industrial fishing fleets continue to grow. More boats are chasing fewer fish.
Overfishing occurs everywhere and is only checked by authorities long after stocks have been depleted. Only one thousandth of the world’s oceans are closed to fishing.
Despite international regulations aimed at overfishing, the high seas remain a lawless place. Regulations are often met in the breach, as the monetary lure is strong and enforcement spotty.
Fish production can only stabilize from fish farming, which began in the 1950s. In 2015, 80 million metric tonnes of seafood came from aquaculture.
Aquaculture is industrialized. The environmental and nutritional results have been predictable.
Caged fish foul the sea around their pens. Fish waste and uneaten feed litter the sea floor beneath aquafarms, generating bacteria that consume oxygen vital to shellfish and other bottom dwellers.
Fish farm waste promotes algal growth that reduces oxygen in the water, posing risks to other aquatic life. But this is just the beginning.
As concentrated targets for viruses, fish farms spread disease and sea lice. To counteract this, antibiotics and pesticides are dumped into the water, poisoning the area around aquaculture farms.
The pesticide that kills sea lice is lethal to other marine invertebrates. This toxic blanket persists in the water for hours and may diffuse for a kilometer around the farm.
All told, the environmental costs of aquaculture have been estimated to be half their production value. Like most other capitalist enterprises, these are costs that fish farmers do not have to pay.
Fish regularly escape their pens. Many interbreed with wild varieties, producing hybrids that can be less capable of survival.
Farmed fish are typically less nutritious than their wild cousins and are stocked with antibiotics and pesticides. Farmed salmon have less than half the healthy omega-3 fats that are a principal benefit of eating fish.
Farming fish does not relieve pressure on wild fish stocks; to the contrary. While some smaller farmed fish are fed corn and soy, the most popular species, such as salmon and tuna, require a fish-based diet. Hence, aquaculture largely relies upon a steady supply of caught fish. As wild fish populations decline, farmed fish stocks will also be depleted for lack of food. Whether caught or farmed, the food bounty from the sea cannot be sustained.
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Based upon current population growth projections, from 2015 to 2050, world food production will need to increase some 60%. This is unlikely to happen.
Already, the number of people in the world that cannot get enough to eat is rising, reaching 815 million in 2016: 11% of the global population.
Agriculture accounts for 70% of global water demand. In the decades to come, there won’t be enough water for the crops and people too.
Agricultural productivity going up is improbable. Indications throughout much of the world are of crop yield plateaus or abrupt decreases. Climate change has already hurt food production.
Despite increasing investment in agricultural science, the relative rate of yield gain for the major food crops has declined. Adding to the stock of arable land can only be done by further decimating forests and thereby gaining soil ill-suited to growing crops. Accelerating climate change is a surefire formula for decreasing crop yields, regardless of acreage.
Half of the food produced in the US goes uneaten, and at least 1/3rd globally. The higher a country’s standard of living, the more food it wastes.
The massive level of food waste equals the acreage of land under cultivation because of economic inefficiency in the market system.
Reducing waste is the best prospect for getting more food out of the current regime. Alas, efficiency is not a capitalist forte, and the commercial food system is unlikely to change without government intervention that is both improbable and doubtful in its ability to attain an efficacious outcome given the current economic system.
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Next, the economic machine that has driven us to extinction.