Marine Heat Waves, Changing Ocean Currents and Capitalism’s Threat to Life
June 8 is World Oceans Day, a day to celebrate and honor the oceans. Today, the oceans are under increasing threat. They’re being degraded by human society, so on World Oceans Day and beyond, let us commit to preserving and protecting the oceans, the source and basis of planetary life.
It would have been unthinkable not many years ago to imagine the impending death of the Great Barrier Reef. The world’s largest living structure and a world heritage site unsurpassed for its tremendous beauty, the Great Barrier Reef has been one of the planet’s most important ecosystems. Now, after consecutive years of prolonged, extreme marine heat waves in 2016 and 2017, one-half of the reef is dead.
Yet the reef, which has gone through immense challenges over millions of years of changing climates, is not entirely gone yet. Leading coral reef scientist Terry Hughes recently told the Guardian that, “The Great Barrier Reef is certainly threatened by climate change, but it is not doomed if we deal very quickly with greenhouse gas emissions. Our study shows that coral reefs are already shifting radically in response to unprecedented heatwaves.”
Further work from other research teams documented in April that globally, marine heat waves have increased in frequency and are of longer duration. Scientists from the Australian Research Council’s Centre of Excellence for Climate Extremes and the Institute of Marine and Antarctic Studies published a study finding that between 1925 and 2016, marine heat waves occurred 34 percent more often, and lasted 17 percent longer. The result has been a 54 percent increase in the number of marine heat wave days happening each year globally.
The study brought together a range of ocean temperature data over the time period studied. Controlling for climate variability, the authors were able to determine that the increase in marine heat waves was related to an increase in sea surface temperature. “With more than 90 percent of the heat from human-caused global warming going into our oceans, it is likely marine heat waves will continue to increase,” said study co-author Neil Holbrook from the University of Tasmania.
The paper cites the impact of recent marine heat waves in a number of the world’s oceans, concluding that, “These events resulted in substantial ecological and economic impacts, including sustained loss of kelp forests, coral bleaching, reduced surface chlorophyll levels due to increased surface layer stratification, mass mortality of marine invertebrates due to heat stress, rapid long-distance species’ range shifts and associated reshaping of community structure, fishery closures or quota changes, and even intensified economic tensions between nations.”
The news of increasing ocean heat waves and their devastating impact is truly alarming, especially in connection with the many other signs of accelerating climate change and general ecological crisis, including in just the past several months.
Arctic, Antarctic Melt and the Ocean Conveyor Belt
After another abnormally warm year in large parts of the Arctic region, including mid-winter temperatures that went above freezing at the North pole, the National Snow and Ice Data Center reported April 2018 essentially tied for the lowest Arctic sea ice extent on record with April 2016. More worrying, not only was the sea ice coverage at a historic April low, but the amount of thicker, multi-year ice cover “has declined from 61 percent in 1984 to 34 percent in 2018. In addition, only 2 percent of the ice age cover is categorized as five-plus years, the least amount recorded during the winter period,” according to the Center.
With the Arctic warming at twice the global average, less ice is forming and more is melting in summer so less of the ice lasts through the warmer months to become multi-year ice. New ice forms in fall and winter, but this ice is now increasingly new, younger ice, instead of building on the thicker and more stable multi-year ice. As ice melts and ice coverage is increasingly younger, less thick and less stable, sea ice is being lost, and the Arctic Ocean is becoming more open in summer. The increasingly ice-free open ocean absorbs the sun’s energy much more readily than the ice-covered ocean, accelerating warming. This dangerous positive feedback loop underway in the Arctic is already impacting climate worldwide.
For the Arctic itself, the disappearing ice threatens to devastate the species and ecosystems that have evolved in connection with it. The decline of Arctic ice and ecosystems, forced by greenhouse gas emissions from the predominant capitalist economies of the planet, also threatens genocide for the culture and way of life of Indigenous peoples throughout the region who have lived for millennia in an ice-covered world.
Another recently published study has shown that melting glaciers in East and West Antarctica are freshening the surrounding ocean and slowing the formation of ocean “bottom water.” Normally, Antarctic bottom water is formed by the sinking of cold, salty water that results as sea ice forms and pushes out salt into surrounding waters. This cold, dense water sinks, mixes with and cools warmer salty water brought by deep ocean currents to Antarctica. But this process is now slowing because of increased glacial freshwater melt. The warm water is stratified, trapped at the bottom, where it is further speeding the melt of Antarctic glaciers from below in these regions. It’s another feedback loop that will likely accelerate sea level rise.
In the Southern Ocean around Antarctica, as well as in the Arctic regions off Norway and Greenland, the process of very dense, cold, salty water sinking is a major factor in causing overturning circulation in the world’s oceans. This is called thermohaline circulation, the process whereby deep-ocean currents are generated by differences in the water’s density, which is controlled by temperature (thermo) and salinity (haline). This is also known as the “ocean conveyor belt.” Ocean currents are very complex and dynamic processes with many factors involved. Essentially though, the ocean conveyor belt drives deep ocean currents that course powerfully around the globe, overturning and mixing enormous quantities of water. In certain regions, this creates upwelling — bringing nutrient-rich water from the ocean’s bottom back to the surface, fueling life. The conveyor belt currents are also a central factor in distributing heat around the planet and stabilizing the Earth’s climate.
Melting sea ice and glaciers are now pouring more fresh water into the ocean, making the waters where this occurs less salty and dense, so less likely to sink. The effects of freshening waters on thermohaline circulation and ocean currents in the Southern Ocean are not yet known, but studies on the North Atlantic this year found that increasing fresh water melt in the Arctic has caused a slowdown in the Atlantic Meridional Overturning Current (AMOC). One of the studies suggested the slowdown has been around 15 percent since 1950. Climatologist Michael Mann said the AMOC slowdown is “happening about a century ahead of schedule relative to what the models predict” and, “I think we’re close to a tipping point.”
What acceleration of ice melt and changing ocean currents will mean for sea level rise that threatens the world coastlines, islands and huge swaths of humanity; for the impact on world climate; and for ocean life and ecosystems that humans also rely on to eat and breathe, is difficult to exactly predict. Nonetheless, it’s clear the climate crisis is already extreme and accelerating. Much depends on whether human society acts quickly to dramatically cut greenhouse gas emissions currently warming the planet, and takes other urgent steps to prevent ecological disaster.
Instead of being reduced, however, carbon emissions continue to grow, recently measured at 410 parts per million, a level not seen in millions of years. In May, the National Oceanic and Atmospheric Administration reported that April 2018 was the 400th straight month that global temperatures were warmer than average.
The Problems of Trump and Capitalism
Faced with this situation of potential ecological catastrophe, Trump and his allies who wield power in the US, lie that global warming is a fabrication, a hoax, or impossible to confirm. They deny the overwhelming evidence and cover over clearly demonstrated science. But this isn’t just a denial of reality, as bad as that is. This is, as The New York Times journalist Justin Gillis said of Scott Pruitt’s denial of climate change, a “civilization-threatening lie.” This is a conscious act that sows confusion, denies people knowledge and prevents them from being able to respond to the existential danger climate change represents. Trump, the Environmental Protection Agency (EPA), the Interior Department and other agencies are moving as fully and as quickly as they can to overturn or eliminate every rule, regulation and barrier that stands in the way of fossil fuel development and use. Their goal is to protect the “freedom” of giant corporations to plunder the natural world to maximize their profitability, and to enhance US “energy dominance,” no matter the destruction it brings.
At the end of May, the EPA announced its official proposal to rollback Obama-era regulations requiring automakers to make cars with higher fuel efficiency standards. If adopted, the likely result is a large increase of greenhouse emissions by the US, already by far the leading contributor to global warming historically. In January, Interior Department head Ryan Zinke announced plans to open up 90 percent of the country’s offshore coastal regions to oil drilling.
Companies have already applied for permits to begin work to develop new oil and gas projects in the Arctic National Wildlife Refuge (ANWR) in Alaska, the largest and most pristine wildlife refuge in the country. Moreover, according to a piece in the Hill, “drilling into the refuge is just the tip of the iceberg. Trump is aggressively pushing Arctic drilling projects on water and land, selling off vast tracts of public lands and oceans, and rolling back drilling safety regulations meant to prevent catastrophic oil spills.”
In May, the White House canceled the vital NASA Carbon Monitoring System that uses satellite and aircraft instruments to track carbon and methane emissions and monitors country’s commitments to greenhouse gas cuts.
Bigger Than Trump
What the Trump regime is doing environmentally (and otherwise) is a threat to planetary life that must be stopped. This crisis, however, didn’t begin with Trump. The operation of the entire world capitalist system has raised greenhouse gases to the level they are and brought us to this juncture. Trump is just the latest and most destructive manifestation of an omnicidal system. The problem we face is that power rests in the hands of a capitalist class that is incapable of confronting our current ecological unraveling as the emergency it is.
The result is a crisis that is inexorably accelerating, with essentially nothing on the level actually needed being done to stop it. Instead of being able to respond from the need to protect life on Earth and world humanity, the capitalist rulers are constrained by the interests and needs of their system for profitability to contend with and beat out rivals.
Karl Marx said presciently of capitalist economic relations, “Modern bourgeois society with its relations of production, of exchange, and of property, a society that has conjured up such gigantic means of production and of exchange, is like the sorcerer who is no longer able to control the powers of the nether world whom he has called up by his spells.”
The capitalist competitive drive for accumulation is why, despite moves by Obama to limit drilling in some places and make modest cuts to greenhouse emissions, fracking and oil and gas production skyrocketed under his administration. It’s also why Canadian Prime Minister Justin Trudeau, who campaigned as a climate change fighter and protector of First Nations rights, has now promised to sink billions of Canadian government dollars into buying the Trans Mountain pipeline that investors were just about to pull out of. Trudeau said of the huge reserves of tar sands oil, the production of which is poisoning Indigenous people and lands in Alberta and the full burning of which would mean climate catastrophe, “No country would find 173 billion barrels of oil in the ground and leave them there.”
Exactly. No capitalist country would. That’s exactly why capitalism cannot be allowed to continue to rule and destroy our planet. Winning a better world, is up to us. What better day to begin, than World Ocean’s Day.
Top Photo: The Great Barrier Reef off the coast of Queensland, Australia. Extreme marine heatwaves in 2016 and 2017 have killed one-half of the reef.Robert Linsdell / Flickr