Impacts on ocean

The oceans have absorbed much of the excess heat from global warming, leading to increased ocean temperatures. Warmer oceans affect marine species and ecosystems, such as coral reefs, which are highly sensitive to temperature changes.

The oceans absorb about a quarter of the CO2 emitted into the atmosphere, leading to ocean acidification. This chemical change can have harmful effects on marine life, particularly organisms with calcium carbonate shells or skeletons, like corals, mollusks, and some plankton species that form the base of the marine food web.

Melting glaciers and ice sheets, along with the thermal expansion of seawater as it warms, are contributing to rising sea levels. This can lead to coastal erosion, increased flooding, and the loss of habitat in coastal and low-lying areas.

Climate change is affecting major ocean currents, including the Gulf Stream and the Antarctic Circumpolar Current, which can alter weather patterns and marine ecosystems around the world.

Warmer waters hold less oxygen, and changes in ocean circulation also reduce the oxygenation of deeper waters. Low oxygen areas, known as hypoxic zones, can create dead zones where marine life struggles to survive.

Just like atmospheric heatwaves, the ocean experiences periods of unusually high temperatures, which can cause mass die-offs of marine species, such as the widespread bleaching of coral reefs.

Changes in sea temperature and acidity, along with deoxygenation, are affecting fish stocks and their distribution, which can impact global fisheries and the livelihoods of those who depend on them.

The distribution of marine species is shifting as they seek out cooler waters, leading to changes in marine biodiversity and the potential for new conflicts over fishing rights.

The Arctic and Antarctic are experiencing reductions in sea ice cover, affecting polar ecosystems, sea levels, and even global climate patterns.

Coastal ecosystems, such as mangroves and salt marshes, are under threat from rising sea levels and changing weather patterns, yet these ecosystems are crucial for carbon sequestration and protecting coastlines from storms.

Rising sea levels and increased storm surges pose risks to coastal communities, including flooding, saltwater intrusion, and damage to infrastructure.

Coral reefs are suffering from both warming temperatures, which cause bleaching, and acidification, which slows the growth of coral skeletons. Reefs are vital for marine life and provide protection for coastlines.