Damage to oceans could be irreparable and deadly

The planet’s oceans protect us from solar radiation and are home to an estimated 70% of all life on earth – but global warming is threatening to destroy entire ecosystems and cause irreparable damage. EURACTIV's partner El País - Planeta Futuro reports.

The Tanzanian coast is lapped by clear, turquoise waters that reveal colourful fish and coral reefs. However, 4,620 km away, the same ocean spills onto a filthy beach in Mumbai, where a sign prohibits people from swimming, although few are tempted to anyway. Tourists taking the ferry to nearby Elephanta Island wrinkle their noses at the oil stains and brownish water that is a product of the refineries that are dotted around the bay. These are the two faces of the Indian ocean and perhaps a glimpse of the future of all the world's oceans if we continue to abuse the environment. They occupy 71% of the planet's surface, yet only 2% are protected.

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Greenhouse gases, produced by industrial activity and transport, among other sectors, are contributing to a gradual warming of the planet. The world's glaciers and ice-caps are melting and, according to NASA, sea levels have risen 8 cm since 1992, with an additional warning that this trend is likely to continue. "The oceans are our bodyguards to some extent, but we are losing this defence," said Ricardo Aguilar, a research director at Oceana Europa, one of the main international organisations dedicated to maritime protection. He referenced the oceans ability to absorb heat and roughly 50% of solar radiation.

The average global temperature has risen by 0.8 degrees Celsius since 1880 and in the last 63 years, the rate of increase has doubled. The most pressing problem to deal with, according to experts, is the acidification of the oceans, caused by the increase in carbon dioxide emissions. When it comes into contact with water, a chemical reaction occurs that increases the acidity. This process has increased 30% since the beginning of industrialisation. This in turn has caused the pH level of the waters to drop by a point, which is completely "without precedent" according to Tatiana Nuño of Greenpeace.

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This process has serious implications for marine ecosystems. Many species such as corals, crabs, clams and oysters are threatened because they cannot develop their shells properly, due to the change in pH level. This has a huge knock-on effect up the food chain. Also endangered are polar grasses and coral reefs, such as the Great Barrier reef in Australia.

"They are fundamental to biodiversity creation, because they are home to nine million species, which depend on the structures for refuge, spawning, nursing and feeding," said Nuño. The increased surface temperature of the water means that it absorbs less oxygen, leading to the deoxygenation of the water and the stunting of marine plant life growth.

Aguilar highlighted the severe consequences of changing temperatures. The melting of the ice-caps means rising sea-levels and a shift of warming ocean currents like the Gulf Stream. "Madrid is roughly at the same latitude as New York, yet we are warm and they are cold. Why? Because of the Gulf Stream. Without it, most of the continent would be under ice. If the current were to shift and no longer bathe Europe in its heat, the impact could be unimaginable, a new ice age," she explained.

Impact on humans

It is not just marine species that are set to be threatened by these effects, humans are also at risk. Of the animal protein ingested by humans, 16.7% comes from fish and crustaceans, according to the Food and Agriculture Organisation of the United Nations (FAO). Less fish means less food.

In Spain, every person eats an average of 26.4 kg a year, according to the latest data from the Ministry of the Environment and Rural and Marine affairs, above the global average. However, demand for fish is greater than ever. FAO statistics show that 158 million tonnes was consumed in 2012, even though 75% of fish stocks are over-exploited or depleted.

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"Over-exploitation is a result of bad management that has gone on for decades. It's been denounced for decades but there has been a total disconnection between experts who have advocated reduced production and politicians. None of the scientific criteria for good management have been respected," said Aguilar.

The fishing sector has to deal with illegal operations that go unreported and unregulated, often using harmful techniques that damage the sea bed and pollute the water. The solution is to create marine reserves, ban industrial-scale fishing and promote smaller-scale, sustainable operations. This would involve a substantial reduction in consumption, in order to allow species to recover sufficiently. "We eat far more animal protein than is necessary, we need to eat less, keeping in mind what we can obtain from sustainable and selective fishing," said Nuño.

"Governments have to be convinced not to allow fishing that exceeds the biological capacity of species, just to satisfy the public," Aguilar added. Indeed, a reduction in consumption would only be necessary on a short-term basis, according to his organisation: "If we reduced fishing by 30% in Europe, today, within ten years fish stocks would recover almost completely and we would be able to carry out twice the amount of fishing we do today."

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Experts are therefore proposing to reduce the activity of a sector that supports 120 million people. According to Aguilar, the international community has to develop economic policies that would support fishermen during a period of time in which they would not be allowed to work. Cristina Narbona, former Spanish minister of the environment, supported the creation of ocean reserves, but denounced the use of fishing subsidies that currently allow fleets that use destructive techniques to operate. "If such aid did not exist, then it would not be profitable and they would carry out sustainable fishing instead," said Narbona, who is also a member of the Spanish Network of Sustainable Development (RED).

Rising global temperatures and sea levels are best seen at the surface, where hundreds of people's very survival is at stake. For example, in Kiribati, its 100,000 inhabitants are fighting a losing battle against the rising tide, with 2030 set as the estimate for when the island nation will begin to significantly sink below the waves.

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They are future climate-refugees and their number could reach a billion in the next 50 years, according to the UN's refugee agency (UNHCR). "It is a phenomenon of such magnitude that humanitarian aid won't cut it: we will need more far-reaching policies," said Estrella Galán, secretary general of the Spanish Committee on Refugee Aid.

In order so that entire countries do not disappear, so that fish stocks recover, so that marine life can regenerate and so that future generations can enjoy clear oceans like in Tanzania, not like in Mumbai, it is likely that global warming will have to be limited to 1.5 degrees by 2050, not two degrees as was originally thought. It is a race against time when one considers that the UN estimates that current emission reduction commitments would still mean a three degrees rise by 2100.

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It remains to be seen whether the ongoing COP21 climate summit in Paris will provide the legally-binding policies that would be necessary to limit global warming.

"Oceans are now on the global agenda, as shown by point 14 of the Sustainable Development Goals, so we are asking that a conference be dedicated every three years to evaluating progress," said Narbona. Nuño, who is optimistic about the compromises made by countries so far, warned that, "it's no good if some sign up and some don't. The agreements have to be obligatory".