By Dr. Marcos Sommer
The world's oceans are absorbing an unprecedented amount of carbon dioxide, which has as a consequence an increase in their degree of acidity and an increased risk of disappearance of many marine species. squares because of global warming.
• "If we are to survive as humanity, we need to drastically change the way we think." Albert Einstein
• “The most vulnerable countries are the least able to protect themselves. They are also the least contributors to global greenhouse gas emissions. If no action is taken, they will pay a high price for the activities of others. " Kofi annan
• “Like slavery, poverty is not a natural state. It is the work of man and can be overcome and eradicated by the action of human beings ”. Nelson Mandela
• "Speed doesn't matter if you're going in the wrong direction." Mahatma Gandhi
• "Alone we can achieve very little, but together we can achieve a lot." Helen Keller
• "If you are neutral in situations of injustice, you have chosen the side of the oppressor." Archbishop Desmond Tutu
• "The injustice done to one is a threat to all." Montesquieu
How does climate change affect the oceans?
The seas and oceans represent 71% of the Earth's surface, 360 million km² and 97% of the terrestrial water resources.
They constitute a great source of biological and natural resources, comparable or even superior to tropical forests. They are also an economic resource and a reserve of energy sources, and are essential regulators of the Earth's climate, as well as highly productive systems that continuously recycle chemicals, nutrients and water. 40% of the world's population lives less than 60 km from the coast and 35 million people depend on fishing. The oceans are an essential source of food and employment, providing natural routes of communication, transportation and trade.
Although over billions of years, the Earth has undergone various types of changes in its climate, the product of various and complex natural factors and some catastrophic (eg asteroid fall, volcanic activity), today in day another totally new factor is added to climate change. It is the one that is being produced due, primarily, to human action.
The main one, among others, is the uncontrolled emission of greenhouse gases, which are modifying the atmosphere in such a way that they are affecting and will significantly affect the Earth's climate, if their emission is not mitigated (all sources). Before the beginning of the industrial revolution (around 1750), the concentration of CO2 in the atmosphere was about 280 parts per million (0.028%) and at the beginning of the 21st century it reaches almost 370 ppmv (0.037%).
The World Symposium on "The effects of climate change on the oceans", held in Gijón (2008), where more than 450 scientists from 60 countries analyzed the effects of change in the oceans, warning about the serious consequences of an increase in temperature in our seas. The consequences of global warming can translate into an increase in the salinity and acidity of the oceans, in addition to the well-known rise in sea level.
The world's oceans are absorbing an unprecedented amount of carbon dioxide (CO2), which has as a consequence an increase in their degree of acidity and an increased risk of disappearance of many marine species, especially those that contain calcium carbonate: corals , mollusks, crustaceans and phytoplankton. According to research papers presented at a colloquium jointly organized by the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the Scientific Committee for Ocean Research (SCOR) of the International Council for Science (2008), this alteration in the degree of acidity could disrupt the marine trophic networks and altering the biological, geological and chemical composition of the oceans in a way that is currently unintelligible and unpredictable (see table 1).
80% of the heat absorbed by the planet goes to the seas, where 60% of the responsibility for the rise in sea level has to do with the increase in temperature. That is why any variation and increase in temperature levels can have serious consequences on the sea level, this is transcendental since the functioning of the oceans directly controls the global climate.
Climate change and what we are living. Great natural disasters that previously occurred every decade, now occur more and more often. These phenomena are occurring with increasing frequency and intensity. The detachment of large blocks of ice is occurring at the poles, giant ice masses of hundreds of km. squares. Although the detachment of those blocks that collapse will not have an effect on the rise in sea level, it means an alert that something is not right, because these detachments of that nature are not usual, it is because of global warming. And that is the area most affected by warming, and Antarctica is the area that has suffered the most from the increase in temperature.
The melting of the Arctic is occurring at a rate considered alarming. The floating masses that cover the Arctic Ocean are estimated to continue to melt rapidly, and there is little doubt that global warming is playing a significant role in their decline. The latest information transmitted by satellites indicates that the extent of the ice in September 2006 was 13.4% less than the average.
Arctic ice today is half as thick as 30 years ago and the area covered by the ice sheet has shrunk by 10%. If the thaw continues, there may be no more ice in the Arctic by 2070.
The increase in global temperature is apparently combining with the variable atmospheric pattern of circulation known as the Arctic Oscillation. As winds and currents push the ice masses south, more of them melt. And when the new ice is still forming in the winter, it is thinner, and therefore melts faster in the summer than the older ice. A point may soon be reached where sea ice can no longer recover.
The melting of the Arctic will necessarily affect the warm and salty Gulf Stream, which would alter the climate of Western Europe and the Eastern US The consequences would be hotter summers that would last longer than usual, and more intense winters with a duration also longer than the current one. But, if the invasion of Arctic waters into the Atlantic, blocks the vital Gulf Stream, it would paradoxically turn Northern Europe into a region with unbearable cold (we are talking about the United Kingdom, Iceland, Norway, and smaller islands, for least). It should be added that the gradual melting of Greenland would also affect the cold Labrador Current that affects the climate on the East coast of the United States, with the consequent climatic effects. In 2002, 51,000 cubic meters of fresh and cold water from the Greenland thaw were dumped into the warm and salty waters of the Gulf Stream. It is estimated that 80% of the ice that covers Greenland is melting at the rate of one meter per year.
In the same way that the oceans remove heat from the atmosphere, they return it to it through the feedback process, so that an increase in temperature could translate into an increase in the intensity of cyclones, typhoons and hurricanes, that would also affect a larger area.
All hurricanes gather their strength from the heat of the oceans, and the world's oceans are warming as a result of climate change. A predictable outcome is the occurrence of more intense storms with stronger winds and higher levels of precipitation.
The melting Arctic will accelerate the pace of global warming. As the ice and snow melt, the Arctic's ability to reflect heat back into space will be reduced, accelerating the overall rate of global warming.
Estimates indicate that the sea level, which already registered an unusual rise in the 20th century, due to the melting of the polar caps, peri-glacial areas and mainly due to the thermal expansion of the oceans, could increase severely. The global mean sea level has already risen by about 15 cm. in the last century and global warming is expected to cause a further increase of about 18 cm. or more by 2030 (Table 2)
Populations that live in low-lying coastal areas, if they cannot adapt to the conditions of an adverse environment due to the rise in sea level, or see their habitat totally flooded, are losing and will lose their homes and settlements, which necessarily means emigrate or be evacuated. This extreme - which is already occurring - will cause a dramatic human, geographical and socioeconomic impact, given that it is estimated that one sixth of the world's population lives above sea level or a few meters above.
The most vulnerable areas are concentrated along the southern coast of the Mediterranean, the west coast of Africa, South Asia (India, Sri Lanka, Bangladesh and the Maldives Archipelago), the coastal states of Southeast Asia and atolls of coral in the Pacific and Indian Oceans. These regions belong to some of the most densely populated and impoverished countries on the planet, with an income of $ 2 or less a day. At the same time, China and South Asia have the most populated coasts in the world, with a density of more than 2,000 people per square kilometer.
In the medium and high impact predictions, the face of the Earth would change completely, many islands will disappear, and large coastal cities or important portions of them, would remain under water, as in the case of Shanghai and New Orleans.
In fishing it is already being noticed, for example, in the outcrop periods that are becoming smaller and less intense, with the implication that this has for the entire food chain and finally, for the fishing sector ”.
Polar bears could be extinct by the end of the century. They are unlikely to survive as a species if there is an almost total loss of the summer ice cover, which is estimated to disappear before the end of the century, according to some climate models.
Currently the variable salinity of the seas and its relationship with precipitation and evaporation, which leads to know if it rains more or less. In places where there is an increase in salinity there is less precipitation and more evaporation.
What are the most affected areas and why?
The actions of man were always insignificant, compared to the magnitude of the marine ecosystem, everything was compensated by nature. The sea and the atmosphere behave as infinite, swallowing the undesirable by-products of human activity. But we became too powerful. We are many and we handle energies capable of altering natural balances. The national use and the management of ecosystems has been in the forefront for years. We are currently experiencing the fragility of marine balances, the answer is given to us by the almost dead Indian and Baltic Seas, the North Sea, whose fish resources are tragically declining, the Mediterranean severely affected and the dying reefs of the entire world.
Fig .: 1. Human impact map, 17 aspects of global change that threaten 20 marine ecosystems are considered. This map allows us to design strategies and set priorities for the management of ecosystems (Source: Halpern B. S., et al. 2008).
The new atlas of the world's oceans (Halpern et. Al., 2008) reveals that human activities have had a strong impact on about 40 percent of their extent, leaving only about 4 percent of them relatively intact (Fig. 1.). The North Sea, the vicinity of Japan, the Caribbean, areas of the Mediterranean, the Persian Gulf or the Red Sea are some of the areas that have been the most damaging, although with climate change the situation is changing rapidly.
The author collected data from different sources and turned it into a model that assigned each square kilometer of ocean a unique value. This value reflects the set of impacts of all human-induced changes in that particular space. The result reveals that there is no area of the ocean that is completely safe from human activities. In each of the square kilometers of our seas, ecological changes are occurring due to anthropogenic causes, the study says. For this reason, in the scale of affection that they have used there is no value 0, but the lowest one refers to an impact less than 1.4. In this sense, and although many areas of the polar regions appear below that figure for now - also the Torres Strait, in northern Australia. As climate change warms these areas, the researchers warn, the hand of man is likely to get there - in full destructive force. However, this analysis does not take into account air pollution, which is particularly high in the Arctic.
Where the impact is, it has reached 41 percent of the oceans, with a medium-high impact. And although the percentage where the affections have been very high only represent 0.5 of the seas, in absolute figures this percentage represents an area of more than 2.2 million square kilometers.
The most affected ecosystems are continental shelves, rocky reefs, coral reefs, grasslands and seamounts. And in addition to the aforementioned regions (eastern Caribbean, North Sea and waters of Japan), the researchers identify other areas with red alert: the China Sea, is its southern and eastern part, the east coast of North America, the Mediterranean Sea. , the Red Sea, the Persian Gulf, and parts of the western Pacific.
The publication by Halpern et al., Presents a database that reveals for the first time the magnitude, geographic extent and precise locations of ocean warming. With this information, citizens, researchers, politicians, etc., can begin to face the bigger problem, of understanding and anticipating how ocean warming will impact on marine ecosystems. Also, the results will help to rank an order of priority for marine conservation projects. For example, fishing areas can be modified and shipping routes redefined to reduce impacts on sensitive ecosystems.
Climate change and its consequences in the oceans.
• The coral reefs that protect and provide sand to the beaches are severely affected or die with ocean temperatures 1º Celsius higher than the average normal maximum of the summer. The heat causes the coral to detach from the algae that feed it, causing it to discolor and turn white. This so-called "bleaching" factor will be higher in the Caribbean and lower in the Central Pacific in the coming decades.
• 27% of the planet's coral reefs are severely damaged today. If global warming persists, a total of 60% of all reefs could be lost by 2030.
• Recent studies find that the global rate of ice melting has doubled since 1988. It is in the Arctic where it is occurring at the fastest rate. Scientists have detected a 40% reduction in the average thickness of ice in the Arctic in the last 40 years.
• Ice in the Arctic Ocean, which is similar in size to that of the United States, decreased by 6% between 1978 and 1996, losing an average per year of 34,300 square kilometers per year, ie a larger area than Holland.
• If the current rate of warming continues, the Arctic ice would cease to exist in the summer of 2050, which could severely affect the Gulf Stream and the climate of Northern Europe.
• Excessive melting of the Arctic ice could have a cooling effect in regions of Europe and the eastern US, since the irruption of fresh water in the North Atlantic could alter the ocean circulation that allows the Current of the Gulf flow to the North.
• The global thaw has led to hunger and weight loss of polar bears, and has altered the habitats as well as the feeding and breeding patterns of penguins and seals.
• The Antarctic ice cover, which represents 91% of land ice, is also melting, although there is no agreement yet as to how fast it is. In the last decades 3 blocks of ice have totally disintegrated: the Wordie, the Larsen A and the Prince Gustavo. Two others, the Larsen B and Wilkins, are expected to do so in the near future as well. If both the western and eastern Antarctic sheets melted, they would cause a 70-meter rise in sea level.
• Some projections suggest that by 2080, the number of people facing severe flooding, in the Caribbean, India and the Pacific Ocean, will be 200 times greater than if there were no rise in sea level.
• The rise in sea level could - for the first time in history - make sovereign states that correspond to small islands disappear. This is the case of Tuvalu, a small island country in the Pacific, whose inhabitants have begun to emigrate to New Zealand as a preventive measure, with the assistance of a plan prepared for this purpose to receive emigrants.
• The Maldives, which has 400,000 inhabitants and is an archipelago of islands in the Indian Ocean (south-western India), has had to evacuate residents from four of its islands in the past years due to rising sea levels. Kiribati lost in 1999, two uninhabited islets, Tebua Tarawa and Abanuea due to the above factor.
• Some beaches in Trinidad, where the sea level has risen four to eight times faster than the global average, are retreating at a rate of 2 meters. per year for the past 15 years. In Fiji, for the same reason, the beaches at Viti, Levu and Taveuni have been withdrawn at a rate of 75 cms. by year.
• At the other end of the world, rising sea levels are already eroding beaches and wetlands in the Chesapeake Bay, which stretches for the most part along the coast of the US state of Maryland. On the east coast of the same, the National Refuge for Wild Life has lost a third of its 8100 hectares and the salinization of the soil due to the advance of the sea, has affected farms that were once fertile lands.
In addition to global warming, what human activities destroy the seas?
The oceans today, at the beginning of the 21st century, suffer serious degradation due to pollution, excessive fishing and the excessive urban coastal growth.
What we know about them is disturbing, signs of the collapse are showing.
• Almost 80 percent of the fish stocks in the oceans are overfished or are being taken to their biological limit. Trawling techniques are harmful and destroy habitats for reproduction (FAO, 2005, Sommer, M., 2005).
• According to a new report by scientists and economists from the University of British Columbia, global fisheries subsidies amount to $ 30-34 billion a year. This huge aid has contributed to producing a global fishing fleet that is 250 percent larger than what is needed for sustainable fishing (Pauly, D., 2008).
• The European Union and Japan are the countries that assign the most subsidies for fishing (Garcia, R. et. Al., 2003).
• Fishing fleets are 40 percent larger than the oceans can support. Fish represent at least one fifth of the total animal protein consumed on earth. About 95 percent of the world's marine fish harvest lives in coastal waters (FAO.org).
• Fishing provides in developing countries between 40 and 100 percent of the total animal protein needed by the population (FAO.org).
• Fishing exploitation is two to three times higher than the rate of reproduction of fish allows (Pauly D. et al., 1998).
• Commercial fishing reduced the world's large fish population by more than 90 percent, jeopardizing a vital source of protein (Waston R. & Pauly D., (2001).
• Fishing for low-value species has increased as the harvest of high-value species has stabilized or declined, thus masking some of the effects of overfishing.
• One billion people depend on fish as a source of animal protein, and 150 million jobs come from fishing (FAO, 2005).
• The alteration of habitats is the consequence of activities such as dredging, landfills, uncontrolled dumping on the coast, construction and coastal roads, deforestation or damage caused by mass tourism. For example, despite the fact that coral reefs cover less than 0.5% of the seabed, 90% of marine species depend directly or indirectly on them. Reefs also protect the population living on the coast by acting as a protective element (Jackson, J.B.C., 1997).
• 60% of today's reefs are in danger of disappearing in the next 30 years if action is not taken. In particular, 85% of European coasts are in danger due to the development of infrastructures and buildings as well as due to natural causes (http://www.coral.org/divein).
• Around 150 whales, dolphins and porpoises die daily worldwide from entanglement with fishing gear, an annual average of 54,759 animals.
• The Atlantic, Pacific and Indian Oceans are slowly warming by an average of 0.06 degrees Celsius since 1955 due to the greenhouse effect. This climate change could lead to a rise in sea levels, which could reach between 9 and 95 centimeters by the end of the century (Parmesan, C. & Yohe, G., 2003, Thomas, CD, et al., 2004 ).
• Approximately half of the world's coastal ecosystems (eg, including coral reefs, mangroves, and grasslands, etc.) are currently at risk of being totally degraded. Some deep-sea corals off the coast of Hawaii will take up to 4,000 years to reach their current size (http://www.coral.org/divein).
• The oceans are becoming increasingly acidic by absorbing carbon dioxide and plants are being affected by increased ultraviolet radiation (Buddemeier R. et al., 2004).
• The merchant marine is responsible for 4.5 of total carbon dioxide emissions, three more than previously thought.
• Ship traffic is the third largest cause of marine pollution. A study prepared by the UN concludes that the C02 emissions of the world merchant fleet reach 1,120 million tons per year and the forecasts do not seem promising: these emissions will increase by 30 percent between now and 2020 if no action is taken (UNEP / UNFCCC, 2002).
• It is estimated that more than 70 thousand synthetic chemicals have been discharged into the world's oceans. Only a small percentage of them have been monitored, and this corresponds to those related to human health and not to ecological impact.
• 80% of marine hydrocarbon pollution comes from activities carried out on land.
• The explosive increase in harmful algae, for example on the coasts of the USA, has implied, since 1991, costs close to 300 million dollars in losses due to the massive death of fish, public health problems and decrease in tourism.
• There are currently more than 405 dead zones (less than 1 square kilometer in size and others reach 70,000 square kilometers) in the world due to the increase in pollution from inland and the loss of habitats capable of filtering pollution, which has caused the expansion of hypoxic zones (Diaz RJ & Rosenberg R., 2008).
• The increase of foreign species in the coastal zones produces the interruption of the food chain by eliminating the native species. Every day, 3,000 species of plants and animals are transported in ships' ballast tanks.
• The world's oceans are home to more than 210,000 known forms of life. About 60 percent of the species live in the 60 km strip. closer to the coast.
• Every year almost 160 new species of fish are found in the oceans and 1,700 animals and plants are cataloged.
• Half of the 6.3 billion inhabitants of the planet live in coastal areas, the great depths of the seas that cover 70 percent of the globe, remain unknown.
• Global warming of the planet will have catastrophic effects on the oceans, slowing down their temperature regulating function. According to the International Panel on Climate Change (IPCC), the frequency and intensity of storms and other meteorological phenomena will increase, damaging marine ecosystems and their resilience (Gilman et al., 2006).
• Since 1980, the size of the global economy has tripled, while the population has increased by 30 percent to 6 billion people. Population increases and conversion for the purposes of urbanization, agriculture and aquaculture are leading to the reduction of mangroves, coastal wetlands, seagrass areas and coral reefs at an alarming rate.
Why should the common man care that the oceans do not deteriorate? How does it harm man?
Among the great challenges of the 21st century, society has to learn that the Oceans are a source of life as well as death. The oceans must, therefore, be appreciated and protected; and if the ecological needs of ocean ecosystems are relegated to oblivion; the state of the marine environment will become an impediment to sustainable development rather than a resource for it.
Only 50 years ago the Ocean was still largely unspoiled wilderness. Today, however, overfishing and pollution are a threat to their health, particularly the coastal areas, which are the most productive in the marine environment.
Fourteen years after entering the Law for the Oceans (United Nations Convention, 1994), the rupture of man's dialogue with the oceans becomes evident and notorious. The growing and unsustainable gap between wealth and poverty threatens the stability of society as a whole and consequently the ecosystem of the oceans, the state of the oceans continues to worsen at alarming proportions. National and international commitments remain in declarations of intent and good will.
The Convention is one of the most important legal instruments of the 20th century. Conceived as a whole, recognizing that all the problems of the ocean space are closely related to each other and must be considered together, it establishes that the seabed and ocean floor and its subsoil beyond the limits of national jurisdiction are the common heritage of humanity that everyone has the right to use them and the obligation to protect them. It provides for mandatory dispute resolution, establishes the global legal framework for all activities carried out in the oceans and seas, and contains detailed rules that regulate all uses of the oceans and define the rights and responsibilities of States.
The oceans, which cover two-thirds of the earth's surface, contain nine-tenths of the world's water resources and 90 percent of the world's living biomass, and are a primary source of food for more than three and a half billion people. persons. They are also a vital economic resource that provides their livelihoods to millions of people around the world.
Approximately 90 percent of international trade is transported by sea. More than 29 percent of the world's oil production comes from the oceans. Beach tourism and cruise ships are an important source of income for many countries, especially small island developing states. Every year almost 130 million tonnes of fish are caught worldwide, with an approximate value of 60 billion dollars, and the fisheries sector and aquaculture alone employ 150 million people.
In addition, the oceans, through their interactions with the atmosphere, lithosphere and biosphere, play a relevant role in shaping the conditions that make possible the different forms of life on the planet. In fact, without the oceans, life would not exist on our planet.
The world should rethink the way economic growth is being measured. Durante mucho tiempo las prioridades de desarrollo se han centrado en lo que la humanidad puede extraer de los ecosistemas, sin pensar demasiado sobre como afecta esto la base biológica de nuestras vidas. Se puede decir que ha habido un progreso muy limitado en la reducción de la pobreza en los países en desarrollo, y la Globalización, por si misma, no ha beneficiado a la mayoría de la población mundial. En general, los intentos por impulsar el desarrollo humano y para detener la degradación del medio oceánico, no han sido eficaces durante la pasada década. Los escasos recursos, la falta de voluntad política, un acercamiento no coordinado, y los contínuos modelos derrochadores de producción y de consumo han frustrado los esfuerzos de poner en ejecución el desarrollo oceánico sostenible, o el desarrollo equilibrado entre las necesidades económicas y sociales de la población, y la capacidad de los recursos oceánicos y de los ecosistemas para resolver necesidades presentes y futuras.
La responsabilidad de proteger los océanos recae no sólo sobre los políticos quienes definen las condiciones nacionales e internacionales de protección de los ecosistemas, sino también es tarea de cada individuo. La exigencia a los políticos para que tomen medidas más efectivas frente a esta problemática debe de estar acompañada del compromiso de cada uno de nosotros por actuar en una forma más responsable en la promoción de la defensa de las metas por la protección de los océanos.
¿Qué soluciones posibles hay para cuidar los océanos?
A principios del siglo XXI es ya evidente que la sociedad detecta y expresa claramente la necesidad de cambio, desde un desarrollo ligado al crecimiento de los años setenta y ochenta hacia un nuevo modelo de desarrollo, un desarrollo verdaderamente sostenible marino en el siglo XXI. Pero, ¿qué entendemos por desarrollo sostenible? Según estableció la Comisión Brundtland en 1987, «es aquel que satisface las necesidades de las generaciones presentes sin comprometer las capacidades de las generaciones futuras para satisfacer sus propias necesidades». Para avanzar en esta dirección, tenemos que conjugar de forma idónea los tres ejes principales del desarrollo sostenible: el medio ambiente, la cultura y la economía dentro de la sociedad (Jiménez Herrero, 2000).
Para conseguir esta síntesis, tenemos que tomar conciencia de la necesidad de datos fiables que nos permitan disponer de unos cimientos sólidos en cada uno de los ejes que sustentan el desarrollo sostenible marino. También hay que conocer y aceptar el nuevo papel de la ciencia Oceanología en la sociedad del siglo XXI que nos permite establecer y situar dentro de unos límites tanto el «Estado del Sistema Marino» como las presiones sobre el mismo (naturales o antropogénicas).
Estos planteamientos iniciales, junto con unas prioridades políticas claras, bien establecidas y, siempre que sea posible, consensuadas, nos permitirán llegar a un punto medio en estos tres ejes.
La ciencia Oceanología ha avanzado mucho en los últimos años y que este avance se puede y se debe traducir en una mejora de los sistemas de gestión ambiental marinos. Una de las pruebas más evidentes es que, con los conocimientos actuales, un gran número de actuaciones del pasado serían ahora distintas. Conviene recordar que nos referimos a múltiples actuaciones con costes de ejecución importantes y costes de reparación medioambiental igualmente cuantiosos, pues como ya hemos indicado, estamos constatando ahora las primeras relaciones directas entre desequilibrios ambientales marinos y repercusiones económicas.
Resumiendo es imprescindible considerar el medio ambiente marino como un tema estratégico para el futuro de la humanidad. Reflexionemos sobre cómo era este planeta hace dos generaciones y cómo será dentro de otras dos. ¿Qué estamos legando a las generaciones futuras? Es ya imprescindible tomar conciencia de la importancia y la necesidad ineludible de considerar el medio ambiente marino y los recursos naturales como un tema estratégico, un tema de Estado por encima de consideraciones políticas. Y hay, efectivamente, espacio para todos. Empleando una de esas divisiones cómodas de la sociedad: los políticos y las distintas administraciones, y exigiendo responsabilidades cuando sea necesario; los científicos, ejecutando una investigación de calidad internacional y proporcionando, siempre que sea posible, respuestas a los requerimientos de la administración, pero siempre, también, desde planteamientos éticos centrados en mejorar el bienestar de las generaciones actuales y futuras (estos principios deben mantenerse tanto en los planteamientos teóricos como en la práctica); finalmente, la sociedad civil, ejerciendo cada día con mayor fuerza y profesionalidad una presión democrática para que todos podamos vivir en un medio ambiente realmente sostenible.
Dr. Marcos Sommer – Oceanógrafos Sin Fronteras – http://www.oceanografossinfronteras.org
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Thomas, C. D., A. Cameron, R. E. Green, M. Bakkenes, L.J. Beaumont, Y. C. Collingham, B. F. N. Erasmus et al.(2004). Extinction risk from climate change. Nature 427: 145-148.
UNEP/UNFCCC (2002). Climate change. Carpeta de información. Disponible en el portal español de la Convención sobre Cambio Climático www.unfccc.int (ver “Información básica” y “publicaciones de referencia”)
Oceanógrafos Sin Fronteras.
Overfishing Scorecard – The Ocean Conservancy
Office of Sustainable Fisheries: NOAA
WWF: Sustainable Fisheries
The Starving Ocean
Guide to Ocean Friendly Seafood – The Blue Ocean Institute
Oceans Alive – Eat Smart
The Empty Ocean: Plundering the World’s Marine Life