The Atlantic Ocean is the second largest ocean on Earth, and it plays a role in nearly every system that sustains human life. It regulates global temperatures, absorbs billions of tons of carbon dioxide, supports massive fishing and shipping industries, and supplies a significant share of the oxygen you breathe. Its importance spans climate, commerce, energy, and ecology.
It Keeps Europe and North America Warm
The Atlantic’s most powerful climate feature is a vast conveyor belt of ocean currents known as the Atlantic Meridional Overturning Circulation, or AMOC. This system pulls warm water northward along the surface from the tropics and sends cold, deep water back south. The heat it carries is staggering: roughly 1.2 petawatts, which is about 100 times larger than total global energy production from all power sources combined.
That northward flow of warm water is the reason the United Kingdom and northwestern Europe have relatively mild winters compared to places at the same latitude in Canada. Without the AMOC, cities like London and Dublin would experience far harsher cold seasons. The system also influences rainfall patterns, hurricane formation, and sea levels along the North American coast.
There are signs this system is weakening. Research published in Science Advances estimates the AMOC has weakened by roughly 3 sverdrups (a unit of ocean flow) since about 1950, and proxy records suggest it may be in its weakest state in over a thousand years. A significant slowdown would cool Northern Europe, shift tropical rain belts, and alter weather patterns across the Northern Hemisphere. This is one of the most closely watched tipping points in climate science.
A Massive Carbon Sink
The world’s oceans absorb a substantial portion of the carbon dioxide that human activity releases into the atmosphere, and the Atlantic is a major contributor. Previous estimates put the global ocean’s carbon uptake at more than 2 gigatons of CO2 per year, roughly a quarter of all human-caused emissions. But research supported by the European Commission found that annual ocean carbon absorption may be 0.8 to 0.9 gigatons higher than earlier observation-based estimates suggested, once measurement corrections are applied.
The Atlantic plays an outsized role in this process because the AMOC actively pulls surface water, along with the CO2 it has absorbed from the air, down into the deep ocean where it can remain stored for centuries. Cold water absorbs more CO2 than warm water, so the deep-water formation zones in the North Atlantic are especially efficient at locking carbon away. If the AMOC weakens further, the Atlantic’s ability to sequester carbon would diminish, leaving more CO2 in the atmosphere and accelerating warming.
Oxygen Production
At least half of the oxygen in Earth’s atmosphere comes from phytoplankton, the microscopic plant-like organisms that float near the ocean’s surface. The Atlantic supports enormous populations of these organisms, particularly in nutrient-rich zones where deep currents bring minerals up to the surface. These blooms are so large they’re visible from space. While no single ocean “owns” a fixed percentage of global oxygen output, the Atlantic’s phytoplankton populations are among the most productive on the planet, fueled by the same circulation patterns that regulate its climate.
Global Trade and Shipping
The Atlantic has been the world’s primary commercial waterway for centuries, and it remains so today. It connects the economies of North America, South America, Europe, and Africa. Major ports like New York, Rotterdam, Hamburg, Santos, and Lagos handle enormous volumes of goods, from oil and natural gas to agricultural products and manufactured goods. Roughly a quarter of global shipping traffic crosses the Atlantic, and the ocean’s geography shapes the trade relationships between the world’s largest economies.
The Panama Canal and the Strait of Gibraltar serve as critical chokepoints linking the Atlantic to the Pacific and Mediterranean, respectively. Disruptions at either location ripple through global supply chains within days. Submarine cables running along the Atlantic floor also carry the vast majority of internet data between continents, making the ocean essential to global communications infrastructure.
Fishing and Food Security
The Atlantic supports some of the world’s most productive fisheries. The Grand Banks off Newfoundland, the North Sea, and the waters off West Africa are among the richest fishing grounds on Earth. Species like Atlantic cod, herring, tuna, shrimp, and lobster feed hundreds of millions of people and support the economies of coastal nations on both sides of the ocean. For many West African countries, Atlantic fisheries are not just an industry but a primary source of protein for the population.
Overfishing remains a serious concern. Several Atlantic fish stocks have been depleted to critical levels over the past few decades, and recovery has been slow even with catch limits in place. The health of these fisheries depends directly on the ocean’s broader ecological balance, including water temperature, oxygen levels, and the plankton populations at the base of the food chain.
Energy Resources
The Atlantic is a growing source of both fossil fuels and renewable energy. Offshore oil and gas fields in the Gulf of Mexico, Brazil’s pre-salt reserves, and fields off the coasts of Norway and West Africa produce a significant share of global petroleum. Brazil alone extracts millions of barrels per day from deep-water Atlantic wells.
Offshore wind is emerging as a major new energy source along the Atlantic coast. Seven U.S. East Coast states have committed to purchasing about 30,000 megawatts of offshore wind electricity by 2035, enough to power roughly 20 million homes. New York alone has set a target of 9,000 megawatts. Projects totaling 11,000 megawatts have already been awarded, and the first large-scale U.S. offshore wind farm began operating off Martha’s Vineyard, Massachusetts, with an 800-megawatt capacity. European countries bordering the North Atlantic, particularly the UK, Denmark, and Germany, are even further along in offshore wind development.
Seabed Minerals and Strategic Resources
The Atlantic seabed contains deposits of manganese, nickel, cobalt, copper, and rare earth elements. These minerals are essential components in batteries, smartphones, defense systems, and medical devices. As demand for electric vehicles and renewable energy storage grows, access to these deep-sea mineral deposits is becoming a factor in national supply chain strategies. NOAA identifies these critical minerals as key to U.S. supply chain resilience, though deep-sea mining remains controversial because of its potential to damage poorly understood ocean floor ecosystems.
Biodiversity and Ecosystem Services
The Atlantic supports an extraordinary range of life, from coral reefs in the Caribbean and the Azores to deep-sea hydrothermal vent communities along the Mid-Atlantic Ridge. It is home to humpback whales, Atlantic bluefin tuna, leatherback sea turtles, and thousands of species of fish, invertebrates, and marine mammals. Mangrove forests along tropical Atlantic coastlines protect shorelines from storm surges and serve as nurseries for commercially important fish species. Salt marshes along the U.S. East Coast and European Atlantic shores filter pollutants and buffer communities against flooding.
These ecosystems are interconnected. The health of coral reefs affects fish populations, which affect the livelihoods of coastal communities. The productivity of phytoplankton influences how much carbon the ocean absorbs, which in turn shapes global climate. The Atlantic is not just a body of water between continents. It is an active, interconnected system that underpins the climate, economy, food supply, and breathable atmosphere that billions of people depend on every day.