About 70% of the Earth’s surface is covered by oceans. Not only were they the womb from which life likely emerged at least 3.5 billion years ago, but they act as the planet’s thermostat, transferring heat from the tropics to higher latitudes and absorbing a substantial amount of the carbon dioxide that the world’s plant life does not convert into oxygen through photosynthesis.

Changes to the ocean chemistry, currents, and temperatures have profound effects on global weather patterns, and human industrial and consumption activity is adversely impacting the oceans and their complex ecosystems. The result is a number of species are being driven to extinction.

Plastic pollution has received much attention in recent years as people cringe at images of tropical beaches covered in plastic bags and bottles, animal deaths caused by plastic, and the massive garbage patches found in all of the world’s largest bodies of water. This increased focus has helped raise awareness of ocean pollution.

Please join in our partnership with MSN to support US service members with a donation to Team Rubicon

But plastic pollution is just one of the issues. A major and often ignored threat to the oceans’ health is greenhouse gas emissions, especially excessive carbon dioxide, which humans are releasing into the atmosphere. These emissions are not only linked to global warming, but also they are causing ocean acidification that is wreaking havoc on marine ecosystems.

In addition to carbon emissions and plastics pollution, oceans are also polluted from oil and chemicals that wash into rivers and wind up in the oceans. This type of pollution, called nonpoint source pollution, includes oil leaked from cars and trucks and runoff from farms and ranches that send herbicides, pesticides, and fertilizers into the oceans via rainwater runoff into rivers.

Taking all three of these major sources of ocean pollution into consideration, 24/7 Wall St. compiled a list of the 20 companies behind among the largest amount of oceanic pollution, including major producers of single-use plastic containers, fossil fuel companies, meat and dairy producers, and agricultural chemical manufacturers responsible for the largest share of oceanic contamination.

It is important to note that this list is not meant to be a conclusive ranking of the world’s top polluters. However, these 20 companies represent our best estimate of the largest polluters in the world, based on their relative size in industries that are known to pollute heavily, as well as estimates of these companies’ greenhouse gas emissions by third parties.

Click here to read about corporations behind the most ocean pollution.
Click here to see our methodology.