Climate campaigners are calling on major US retailers to switch to zero-emissions shipping practices as a matter of urgency, after estimating that four companies accounted for 20 million tonnes of carbon emissions in just two years. 

A report published this week by Ship It Zero, a coalition of environmental campaign groups such as and Pacific Environment, calls for immediate action from Walmart, Target, Amazon and Ikea, which together account for around 7% of US imports. 

Between 2018 and 2020, the report says pollution from those four companies’ maritime supply chains are equivalent to the annual emissions from five coal-fired power plants. 

“Pandemic-fuelled demand increases, record-breaking profits, and the supply chain crisis reveal the current maritime shipping system is ripe for transformation,” says Kendra Ulrich,’s shipping campaigns director. 

“There is ample room for retail brands and cargo carriers to absorb the cost of transitioning to fossil-free, zero-emissions shipping and deliver healthier air to our port communities and a liveable climate future.” 

The US retail sector has experienced a boom in demand during 2021, particularly for goods produced in Asia. The report says transpacific routes have historically accounted for the largest share of carbon emissions, at 21% in the two years examined. 

Rising imports, coupled with port congestion and growing numbers of ships idling offshore, mean local communities are “saddled with increasing rates of pollution”, the report says. 

It acknowledges that Amazon and Ikea have already taken steps towards tackling the problem, including helping launch coZEV – an initiative by retailers to move all products away from fossil-fuelled cargo vessels by 2040. 

However, it says the duo should “take immediate steps to reduce their maritime emissions”, pointing out that only a small portion of their ocean shipping will be decarbonised by 2030. 

In the case of Walmart and Target, the report says both “must take responsibility for their maritime pollution… and commit to transition to 100% zero-emissions ocean shipping by 2030”. 

When contacted by GTR, a spokesperson for Ikea said emissions from ocean shipping is an important topic for the company. 

“Ikea is committed to become climate positive by 2030, by reducing more greenhouse gas emissions than the Ikea value chain emits,” they say. “We are committed to reduce the carbon footprint from all our transport by 70% by 2030, compared to 2017.” 

That transition involves switching to zero emissions technology, such as the use of biofuels on deep ocean container ships.  

That process is currently being scaled up, the company says. Such technology is not without controversy, however, with a May letter from a group of NGOs arguing biofuels should not be promoted in the shipping sector due to limitations in sustainable feedstock. 

Amazon declined to comment when contacted by GTR, but the company says it has pledged to reach net-zero emissions across the entire company by 2040. It also helped launch the First Movers Coalition, which uses the collective purchasing powers of companies to scale up production of emerging transitional technologies. 

A spokesperson for Target says the company has also set a target of being a net-zero enterprise by 2040, across both operations and supply chain. 

“Through our sustainability strategy Target Forward, we’re committed to putting our business to use to positively impact both people and the planet,” they add. 

Walmart says it too has committed to reaching net zero across its operations by 2040, including from across its fleet of vessels. The retailer has also launched Project Gigaton, which aims to avoid a gigaton of emissions from the global value chain by 2030, with more than 3,000 suppliers signed up. 

“Additionally, most of the products we source for our retail business in the US were made, grown or assembled domestically, including two-thirds of merchandise sold in Walmart US,” a spokesperson adds. 

The pressure on the four retailers comes as world leaders attempt to support the creation of “green” shipping corridors. 

The Clydebank Declaration, signed at the Cop26 climate summit in November, aims to establish at least six net-zero emissions routes by 2025. Options considered so far include the container route from Asia to Europe, and the Northeast Asia-to-US car carrier route.