Query: “The oceans will never become acid because there is such a huge buffering capacity in the oceans.

Relevant passages:
Biodiversity <=SEP=> Biodiversity a portmanteau of `` biological diversity , '' generally refers to the variety and variability of life on Earth . According to the United Nations Environment Programme , biodiversity typically measures variation at the genetic , the species , and the ecosystem level . Terrestrial biodiversity tends to be greater near the equator , which seems to be the result of the warm climate and high primary productivity . Biodiversity is not distributed evenly on Earth , and is richest in the tropics . These tropical forest ecosystems cover less than 10 per cent of earth 's surface , and contain about 90 percent of the world 's species . Marine biodiversity tends to be highest along coasts in the Western Pacific , where sea surface temperature is highest and in the mid-latitudinal band in all oceans . There are latitudinal gradients in species diversity . Biodiversity generally tends to cluster in hotspots , and has been increasing through time , but will be likely to slow in the future .   Rapid environmental changes typically cause mass extinctions . More than 99.9 percent of all species , amounting to over five billion species , that ever lived on Earth are estimated to be extinct . Estimates on the number of Earth 's current species range from 10 million to 14 million , of which about 1.2 million have been documented and over 86 percent have not yet been described . More recently , in May 2016 , scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described . The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes . In comparison , the total mass of the biosphere has been estimated to be as much as 4 TtC ( trillion tons of carbon ) . In July 2016 , scientists reported identifying a set of 355 genes from the Last Universal Common Ancestor ( LUCA ) of all organisms living on Earth .   The age of the Earth is about 4.54 billion years old . The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago , during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon . There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia . Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland . More recently , in 2015 , `` remains of biotic life '' were found in 4.1 billion-year-old rocks in Western Australia . According to one of the researchers , `` If life arose relatively quickly on Earth . . then it could be common in the universe . ''   Since life began on Earth , five major mass extinctions and several minor events have led to large and sudden drops in biodiversity . The Phanerozoic eon ( the last 540 million years ) marked a rapid growth in biodiversity via the Cambrian explosion -- a period during which the majority of multicellular phyla first appeared . The next 400 million years included repeated , massive biodiversity losses classified as mass extinction events . In the Carboniferous , rainforest collapse led to a great loss of plant and animal life . The Permian -- Triassic extinction event , 251 million years ago , was the worst ; vertebrate recovery took 30 million years . The most recent , the Cretaceous -- Paleogene extinction event , occurred 65 million years ago and has often attracted more attention than others because it resulted in the extinction of the dinosaurs .   The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity . Named the Holocene extinction , the reduction is caused primarily by human impacts , particularly habitat destruction . Conversely , biodiversity impacts human health in a number of ways , both positively and negatively .   The United Nations designated 2011 -- 2020 as the United Nations Decade on Biodiversity .

United Nations Ocean Conference <=SEP=> The 2017 United Nations Ocean Conference was a United Nations conference that took place on June 5th-9th 2017 which sought to mobilize action for the conservation and sustainable use of the oceans, seas and marine resources.The Earth's waters are said to be "under threat as never before", with pollution, overfishing, and the effects of climate change severely damaging the health of our oceans. For instance as oceans are warming and becoming more acidic, biodiversity is becoming reduced and changing currents will cause more frequent storms and droughts. Every year around 8 million metric tons of plastic waste leak into the ocean and make it into the circular ocean currents. This causes contamination of sediments at the sea-bottom and causes plastic waste to be embedded in the aquatic food chain. It could lead to oceans containing more plastics than fish by 2050 if nothing is done. Key habitats such as coral reefs are at risk and noise pollution are a threat to whales, dolphins, and other species. Furthermore almost 90 percent of fish stocks are overfished or fully exploited which cost more than $80 billion a year in lost revenues.UN Secretary-General António Guterres stated that decisive, coordinated global action can solve the problems created by Humanity. Peter Thomson, President of the UN General Assembly, highlighted the conference's significance, saying "if we want a secure future for our species on this planet, we have to act now on the health of the ocean and on climate change".The conference sought to find ways and urge for the implementation of Sustainable Development Goal 14. Its theme is "Our oceans, our future: partnering for the implementation of Sustainable Development Goal 14". It also asked governments, UN bodies, and civil society groups to make voluntary commitments for action to improve the health of the oceans with over 1,000 commitments − such as on managing protected areas − being made.

Sea <=SEP=> A sea is a large body of salt water that is surrounded in whole or in part by land . More broadly , `` the sea '' is the interconnected system of Earth 's salty , oceanic waters -- considered as one global ocean or as several principal oceanic divisions . The sea moderates Earth 's climate and has important roles in the water cycle , carbon cycle , and nitrogen cycle . Although the sea has been traveled and explored since prehistory , the modern scientific study of the sea -- oceanography -- dates broadly to the British Challenger expedition of the 1870s . The sea is conventionally divided into up to five large oceanic sections -- including the International Hydrographic Organization 's four named oceans ( the Atlantic , Pacific , Indian , and Arctic ) and the Southern Ocean ; smaller , second-order sections , such as the Mediterranean , are known as seas .   Owing to the present state of continental drift , the Northern Hemisphere is now fairly equally divided between land and sea ( a ratio of about 2:3 ) but the South is overwhelmingly oceanic ( 1:4.7 ) . Salinity in the open ocean is generally in a narrow band around 3.5 % by mass , although this can vary in more landlocked waters , near the mouths of large rivers , or at great depths . About 85 % of the solids in the open sea are sodium chloride . Deep-sea currents are produced by differences in salinity and temperature . Surface currents are formed by the friction of waves produced by the wind and by tides , the changes in local sea level produced by the gravity of the Moon and Sun . The direction of all of these is governed by surface and submarine land masses and by the rotation of the Earth ( the Coriolis effect ) .   Former changes in sea levels have left continental shelves , shallow areas in the sea close to land . These nutrient-rich waters teem with life , which provide humans with substantial supplies of food -- mainly fish , but also shellfish , mammals , and seaweed -- which are both harvested in the wild and farmed . The most diverse areas surround great tropical coral reefs . Whaling in the deep sea was once common but whales ' dwindling numbers prompted international conservation efforts and finally a moratorium on most commercial hunting . Oceanography has established that not all life is restricted to the sunlit surface waters : even under enormous depths and pressures , nutrients streaming from hydrothermal vents support their own unique ecosystem . Life may have started there and aquatic microbial mats are generally credited with the oxygenation of Earth 's atmosphere ; both plants and animals first evolved in the sea .   The sea is an essential aspect of human trade , travel , mineral extraction , and power generation . This has also made it essential to warfare and left major cities exposed to earthquakes and volcanoes from nearby faults ; powerful tsunami waves ; and hurricanes , typhoons , and cyclones produced in the tropics . This importance and duality has affected human culture , from early sea gods to the epic poetry of Homer to the changes induced by the Columbian Exchange , from burial at sea to Basho 's haikus to hyperrealist marine art , and inspiring music ranging from the shanties in The Complaynt of Scotland to Rimsky-Korsakov 's `` The Sea and Sinbad 's Ship '' to A-mei 's `` Listen to the Sea '' . It is the scene of leisure activities including swimming , diving , surfing , and sailing . However , population growth , industrialization , and intensive farming have all contributed to present-day marine pollution . Atmospheric carbon dioxide is being absorbed in increasing amounts , lowering its pH in a process known as ocean acidification . The shared nature of the sea has made overfishing an increasing problem .

Fisheries and climate change <=SEP=> Rising ocean temperatures and ocean acidification are radically altering aquatic ecosystems . Climate change is modifying fish distribution and the productivity of marine and freshwater species . This has impacts on the sustainability of fisheries and aquaculture , on the livelihoods of the communities that depend on fisheries , and on the ability of the oceans to capture and store carbon ( biological pump ) . The effect of sea level rise means that coastal fishing communities are in the front line of climate change , while changing rainfall patterns and water use impact on inland ( freshwater ) fisheries and aquaculture .