The role of the Ocean
Global warming is taking its toll on the World Ocean, but what will this mean for humanity ?
As the IPCC released its latest report on the expected impact of global warming, Nausicaa and the World Ocean Network sought to stress once again that the Ocean plays a crucial role in the planet’s ecological systems and is of fundamental importance for humanity – today, ‘the ocean problem’ is causing concern among a large number of specialists from all over the world.
Today, the Ocean is absorbing 80 % of the excess CO2 emitted by human activities
The Ocean has warmed to depths of several thousands of metres, with irreversible consequences both for the Ocean and for humanity. We are only just beginning to understand the implications of this warming, but we already know that:
• From a Living marine resources perspective, the geographic displacement of fish stocks, already weakened by industrial overfishing (not to mention the displacement of their own food supply – plankton and other fish – also the direct result of changing marine conditions) will accelerate as species and populations instinctively seek conditions in which they can survive elsewhere. Those which cannot adapt or migrate will rapidly become extinct, adding to worldwide biodiversity loss and diminishing the vital resources of the Ocean on which humanity depends. Not only will our food supplies be affected, but entire economies and societies will suffer. The combination of overfishing, global warming and the impact of pollution from the land could soon transfrom many ocean regions into deserts inhabited only by dense shoals of jellyfish, as is already happening in the Black Sea, in the Baltic Sea and in the Sea of Japan. Fishing based economies simply cannot survive in these conditions.
• Less well understood by the general public is that ocean acidification is already having serious effects on the marine organisms which need calcium carbonate to grow their shells. Corals are also at risk. Corals are important marine ecosystems and habitats for thousands of species but are also important for human communities, providing fishing and tourism resources, as well as protection from tsunamis. Their degradation would probably have devastating consequences for species survival, and especially for some phytoplankton species at the base of the marine food chain; and such organisms, it is worth remembering, provide us with most of the oxygen we breathe.
• It is believed that melting glaciers will lead to rising sea levels and the thermal expansion of surface ocean waters. These rising sea levels will probably have irreversible consequences for the circulation of the major ocean currents, which we know interact closely with the Earth’s climate. Climate change is also likely to be accelerated by the rise in average ocean temperatures because, through its thermal inertia, the Ocean is the main regulator of the Earth’s climate, as the El Nino phenomenon highlights in dramatic fashion. On top of this the arctic ice cap is melting, and as it does so it reflects less and less of the sun’s radiation. The extra heat retained will accelerate the global warming process.
• Of course, the rising level of the World Ocean will also have an incalculable economic and humanitarian impact on mankind. Half of the world’s population lives on the coasts and in 30 years this percentage is expected to jump to ¾...that is ¾ of some 9 to 10 billion people, increasing the total coastal population from 3 to 6 billion. Land loss from a 1m rise in sea level is estimated at 1% for Egypt, 6% for the Netherlands, 17.5% for Bangladesh and up to around 80% for the Majuro Atoll, the capital of the Marshall Islands. And a more extreme scenario of a rise of some 6 to 8 metres cannot be ruled out. We must therefore expect to experience the largest migration of refugees the world has ever seen.
• France, which, by virtue of its overseas territories, is the second largest maritime nation in the world, cannot escape these phenomena. Yet the question of the Ocean is, so far, barely audible in the discussions between politicians, scientists and business leaders.
If we do not take steps to put the question of the preservation of the Ocean and its resources at the heart of the global warming debate, attempting to limit its effects and thereby saving humanity will become impossible. Before it is too late, we must make the case. There’s still time.
« For the future of the Blue Planet, we can make a difference » (World Ocean Network, 1999)
Discover more with the Atlas of the World Ocean
More information on these issues can be found in the Atlas de l’Océan Mondial (Atlas of the World Ocean), jointly authored by Jean-Michel Cousteau and Philippe VALLETTE, and jointly edited by Editions Autrement and Nausicaa. It will be available from bookshops shortly.
An increase in global temperatures with very significant consequences now seems unavoidable. For this reason the Atlas « Pour une politique durable de la planète mer » (Towards a sustainable policy for our planet ocean) seeks to put the Ocean at the heart of the international environmental debate.
It is incumbent on us to try to limit the consequences of global warming, both for those whose livelihoods depend directly on the Ocean, but also, beyond them, for the entire population of the planet.
