Pandemic shipping took a heavy toll on the climate

'Public health and the climate cannot wait for an entirely new generation of vessels.'
Crane loading cargo onto ship at sunset
In 2021, 1,650 ships generated 3.5 million metric tons of greenhouse gas emissions. Deposit Photos

Many Americans remained locked down and logged online throughout 2021, changing the way people shopped for countless goods and services. Initial coverage frequently focused on the ensuing supply chain woes, but new research is showcasing another grave consequence to all that consumption—the ocean shipping industry boom generated massive amounts of greenhouse gasses. 

Although their pollution statistics rarely make into the news as much as everyday cars, “dirty cargo ships” running on fossil fuels bring an estimated 40 percent of America’s goods into the country each year, and are a major impediment towards transitioning to a greener society. Because individual ships are often connected to dozens of international companies, it is often difficult to assign emissions regulation responsibilities. Meanwhile, thousands of ships burn sulfur-heavy “bunker fuel” that, while sometimes “scrubbed” via exhaust cleaning systems, still produces hazardous waste often dumped into oceans.

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Commissioned by Ship It Zero, a coalition advocating for ocean freight companies’ transition to clean-energy, the “All Brands on Deck” report analyzes 2021’s international imports from 18 of America’s foremost retailers, including Walmart, The Home Depot, Target, Amazon, and Samsung. The findings aren’t pretty—an estimated 4.7 million containers traveling aboard over 1,650 ships generated approximately 3.5 million metric tons of greenhouse gas emissions in 2021 alone. That’s equivalent to the carbon dioxide belched from 754,000 traditional gas-powered cars, or the energy required to power 440,000 US homes. As Canary Media also notes, “ships spewed enough smog-forming nitrogen oxide to equal the annual emissions of seven coal-fired power plants.”

Most of these imports entered the country through a few major port hubs: Los Angeles and Long Beach, California, alongside Houston, Texas, and Savannah, Georgia. The report explains that due to port  locations, much of the ocean vessels’ asthma- and cancer-causing pollutants most often affect port-adjacent and coastal communities with disproportionately Black, Indigenous, and Brown working class populations.

Walmart, Target, and Home Depot were among the worst offenders analyzed. Their combined  shipping contracts generated over 1.7 million metric tons of CO2 and 33 metric tons of methane in 2021. “Buoyed by reliance on the cheapest, most deadly fossil fuels on the planet, international shipping companies and the corporations that rely on them make billions while treating our oceans, health and climate as externalities,” explains the report’s authors. “For far too long, they’ve gotten away with it.”

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Ship It Zero hopes that highlighting these troubling figures and increasing pressure on corporations will spur them to speed their transitions towards cleaner shipping options, like fuel cells, marine batteries, and wind harnessing equipment. Currently, both Walmart and The Home Depot have made no public commitments to fossil fuel-free maritime shipping plans, despite generating “the highest levels of carbon dioxide, methane and carcinogenic particulate matter pollution of all companies studied,” the report reads.

As part of their suggested path forward, Ship It Zero urges these companies to ask ocean carriers to demonstrate immediate and year-over-year emission reduction efforts during contract negotiation periods. “Any ship on the water today could be retrofitted with wind- assist propulsion or other emissions reducing technologies,” argues the authors. “[P]ublic health and the climate cannot wait for an entirely new generation of vessels.”