A new study revealed that the global supply chains of multinational corporations are contributing to the high levels of global carbon emissions.
The corporations outsource many of these emissions to poorer parts of the world by investing in production in developing countries, said researchers from University College London and China's Tianjin University.
Dabo Guan, the study's co-author, called the work the "first quantitative evidence" on the investment flows and carbon footprints of multinational enterprises (MNEs).
"The results were quite shocking. For many large companies, emissions from their supply chains ... (are) larger than the emissions of many countries," he told the Thomson Reuters Foundation.
For example, emissions from the supply chain producing Coca-Cola products is almost equivalent to what China emits in its food sector to feed 1.3 billion people, he said.
Similarly, foreign affiliates of Walmart emit more than Germany's retail sector while Samsung's emissions around the world are higher than all electronic manufacturers in India, Thailand, and Vietnam, the study found.
A spokesperson for Walmart, the world's biggest retailer, said the company is aiming to avoid one billion metric tons (a gigaton) of emissions from its global value chain by 2030 through an initiative called Project Gigaton.