Editing Atlantic Ocean (section)

== Environmental issues ==

=== Endangered species ===
{{Expand section|date=December 2020}}
Endangered marine species include the [[manatee]], [[Pinniped|seals]], sea lions, turtles, and whales. [[Drift net]] fishing can kill dolphins, [[albatross]]es and other seabirds ([[petrel]]s, [[auk]]s), hastening the fish stock decline and contributing to international disputes.<ref>{{Cite web|last=Eisenbud|first=R.|year=1985|title=Problems and Prospects for the Pelagic Driftnet|url=http://www.animallaw.info/articles/arus12bcenvtlafflrev473.htm|url-status=live|archive-url=https://web.archive.org/web/20111125082226/http://animallaw.info/articles/arus12bcenvtlafflrev473.htm|archive-date=25 November 2011|access-date=27 October 2011|publisher=Michigan State University, Animal Legal & Historical Center}}</ref>

=== Waste and pollution ===
[[Marine pollution]] is a generic term for the entry into the ocean of potentially hazardous chemicals or particles. The biggest culprits are rivers and with them many agriculture [[fertilizer]] chemicals as well as livestock and human waste. The excess of oxygen-depleting chemicals leads to [[Hypoxia (environmental)|hypoxia]] and the creation of a [[dead zone (ecology)|dead zone]].<ref>Sebastian A. Gerlach "Marine Pollution", Springer, Berlin (1975)</ref>

[[File:Nesocichla eremita -Inaccessible Island, British overseas territory-8 (3).jpg|thumb|[[Marine debris]] strewn over the beaches of the South Atlantic [[Inaccessible Island]]]]
[[Marine debris]], which is also known as marine litter, describes human-created waste floating in a body of water. Oceanic debris tends to accumulate at the center of [[Oceanic gyres|gyres]] and coastlines, frequently washing aground where it is known as beach litter. The [[North Atlantic garbage patch]] is estimated to be hundreds of kilometers across in size.<ref>{{Cite news|date=2 March 2010|title=Huge Garbage Patch Found in Atlantic Too|work=National Geographic|url=https://www.nationalgeographic.com/news/2010/3/100302-new-ocean-trash-garbage-patch/|archive-url=https://web.archive.org/web/20190828221810/https://www.nationalgeographic.com/news/2010/3/100302-new-ocean-trash-garbage-patch/|url-status=dead|archive-date=28 August 2019}}</ref>

Other pollution concerns include agricultural and municipal waste. Municipal pollution comes from the eastern United States, southern Brazil, and eastern Argentina; [[oil pollution]] in the [[Caribbean Sea]], [[Gulf of Mexico]], [[Lake Maracaibo]], [[Mediterranean Sea]], and [[North Sea]]; and industrial waste and municipal sewage pollution in the Baltic Sea, North Sea, and Mediterranean Sea.

A USAF [[C-124 Globemaster II|C-124]] aircraft from [[Dover Air Force Base]], Delaware was carrying three [[nuclear bombs]] over the Atlantic Ocean when it experienced a loss of power. For their own safety, the crew jettisoned two nuclear bombs, which were never recovered.<ref>{{Cite web|last=HR Lease|date=March 1986|title=DoD Mishaps|url=http://www.afrri.usuhs.mil/outreach/reports/pdf/SP86-2.pdf|url-status=dead|archive-url=https://web.archive.org/web/20081218233551/http://www.afrri.usuhs.mil/outreach/reports/pdf/SP86-2.pdf|archive-date=18 December 2008|publisher=[[Armed Forces Radiobiology Research Institute]]}}</ref>

=== Climate change ===
{{See also|Shutdown of thermohaline circulation|}}

North Atlantic hurricane activity has increased over past decades because of increased [[sea surface temperature]] (SST) at tropical latitudes, changes that can be attributed to either the natural [[Atlantic Multidecadal Oscillation]] (AMO) or to [[anthropogenic climate change]].<ref name="Mann">{{Harvnb|Mann|Emanuel|2006|pp=233–241}}</ref>
A 2005 report indicated that the Atlantic [[meridional overturning circulation]] (AMOC) slowed down by 30% between 1957 and 2004.<ref>{{Harvnb|Bryden|Longworth|Cunningham|2005|loc=Abstract}}</ref> In 2024, the research highlighted a significant weakening of the AMOC by approximately 12% over the past two decades.<ref>{{Cite web|last1=Marine|first1=Rosenstiel School of|last2=Atmospheric|last3=Science|first3=Earth|title=Warming of Antarctic deep-sea waters contribute to sea level rise in North Atlantic, study finds|url=https://phys.org/news/2024-04-antarctic-deep-sea-contribute-north.html|access-date=19 April 2024|website=phys.org|language=en}}</ref> If the AMO were responsible for SST variability, the [[Atlantic meridional overturning circulation|AMOC]] would have increased in strength, which is apparently not the case. Furthermore, it is clear from statistical analyses of annual tropical cyclones that these changes do not display multidecadal cyclicity.<ref name="Mann" /> Therefore, these changes in SST must be caused by human activities.<ref>{{Harvnb|Webster|Holland|Curry|Chang|2005}}</ref>

The ocean [[mixed layer]] plays an important role in heat storage over seasonal and decadal time scales, whereas deeper layers are affected over millennia and have a heat capacity about 50 times that of the mixed layer. This heat uptake provides a time-lag for climate change but it also results in thermal expansion of the oceans which contributes to [[sea level rise]]. 21st-century global warming will probably result in an [[equilibrium level|equilibrium sea-level]] rise five times greater than today, whilst melting of glaciers, including that of the Greenland ice sheet, expected to have virtually no effect during the 21st century, will likely result in a [[Sea level rise|sea-level rise]] of {{Convert|3-6|m|ft}} over a millennium.<ref>{{Harvnb|Bigg|Jickells|Liss|Osborn|2003|loc=Sea-level change, pp. 1128–1129}}</ref>