Climate change is causing our oceans to become increasingly acidic, threatening to alter life as we know it.

“From a climate change/fisheries/pollution/habitat destruction point of view, our nightmare is here, it’s the world we live in.”

This bleak statement about the current status of the world’s oceans comes from Dr Wallace Nichols, a Research Associate at the California Academy of Sciences. Al Jazeera asked Dr Nichols, along with several other ocean experts, how they see the effects climate change, pollution and seafood harvesting are having on the oceans.

Their prognosis is not good.

Dr Nancy Knowlton is a marine biologist at the Smithsonian Museum of Natural History in Washington DC. Her research has focused on the impact of climate change on coral reefs around the world, specifically how increasing warming and acidification from carbon dioxide (CO2) emissions have affected oceans.

While she is unable to say if oceans have crossed a tipping point, Dr Knowlton offered this discouraging assessment, “We know it’s bad and we know it’s getting worse, and if we care about having coral reefs, there’s no question we have to do something about CO2 emissions or we won’t have coral reefs, as we do now, sometime between 2050-2100.”

Since at least one quarter of all species of life in the oceans are associated with coral reefs, losing them could prove catastrophic.

“Coral reefs are like giant apartment complexes for all these species, and there is intimacy,” Dr Knowlton explained. “If that starts breaking down, these organisms, which include millions of species around the world, lose their homes. Even if they aren’t eating coral, they depend on it.”

CO2 is the main greenhouse gas resulting from human activities in terms of its warming potential and longevity in the atmosphere, and scientists continually monitor its concentration.

In March 1958, when high-precision monitoring began, atmospheric CO2 was 315.71 parts per million (ppm). Today, atmospheric CO2 is approaching 390 ppm.

350 ppm is the level many scientists, climate experts, and progressive national governments say is the safe upper limit for CO2 in the atmosphere.

“You see evidence of the impact of climate change on the oceans everywhere now,” Dr Nichols said. “The collapsing fisheries, the changes in the Arctic and the hardship communities that live there are having to face, the frequency and intensity of storms, everything we imagined 30 to 40 years ago when the environmental movement was born, we’re dealing with those now … the toxins in our bodies, food web, and in the marine mammals, it’s all there.”

Bleak scenario

The Zoological Society of London reported in July 2009 that “360 is now known to be the level at which coral reefs cease to be viable in the long run.”

In September 2009 Nature magazine stated that atmospheric CO2 levels above 350 ppm “threaten the ecological life-support systems” of the planet and “challenge the viability of contemporary human societies.”

In their October 2009 issue, the journal Science offered new evidence of what the earth was like 20 million years ago, which was the last time we had carbon levels this high. At that time, sea levels rose over 30 metres and temperatures were as much as 18 degrees C higher than they are today.

According to the Intergovernmental Panel on Climate Change, carbon emissions have already risen “far above even the bleak scenarios.”

Oceans absorb 26 per cent (2.3bn metric tonnes) of the carbon human activities released into the atmosphere annually, according to a 2010 study published by Nature Geocience and The Global Carbon Project.

Unfortunately, global carbon emissions, rather than slowing down in order to stem climate change, are continuing to increase.

At a 2008 academic conference Exeter University scientist Kevin Anderson showed slides and graphs “representing the fumes that belch from chimneys, exhausts and jet engines, that should have bent in a rapid curve towards the ground, were heading for the ceiling instead”.

He concluded it was “improbable” that we would be able to stop short of 650 ppm, even if rich countries adopted “draconian emissions reductions within a decade”.

That number, should it come to pass, would mean that global average temperatures would increase five times as much as previous models predicted.

According to the National Climate Data Centre in the US, 2010 was the warmest year on record. September 2011 was the 8th warmest September on record since 1880. At 15.53°C, August’s global temperature is 0.53 C higher than the 20th Century average for that month.

Even if CO2 emissions were completely stopped immediately, ongoing impacts from climate change would take centuries to stop.

The US National Oceanic and Atmospheric Administration released a study in 2009 showing that a new understanding of ocean physics proved that “changes in surface temperature, rainfall, and sea level are largely irreversible for more than a thousand years after carbon dioxide emissions are completely stopped”.

Increasing acidification

Many factors concern Knowlton and Nichols, but one in particular, the increasing acidification of the oceans, has been gaining more attention as of late.

Historically, oceans have been chemically constant, but less than 10 years ago oceanographers were shocked when researchers noticed the seas were acidifying - 30 per cent more acidic - as they absorbed more of the carbon dioxide humans have emitted into the atmosphere, a process that Britain’s Royal Society has described as “essentially irreversible.”

The oceans are already more acidic than they have been at any time in the last 800,000 years. At current rates, by 2050 it will be more corrosive than they have been in the past 20 million years.

Acidification occurs when CO2 combines with seawater to form carbonic acid.

Sarah Cooley, a marine geochemist with the Woods Hole Oceanographic Institution, wrote this about acidification:

“As CO2 levels driven by fossil fuel use have increased in the atmosphere since the Industrial Revolution, so has the amount of CO2 absorbed by the world’s oceans, leading to changes in the chemical make-up of seawater. Known as ocean acidification, this decrease in pH creates a corrosive environment for some marine organisms such as corals, marine plankton, and shellfish that build carbonate shells or skeletons.”

Already ocean pH has slipped from 8.2 to 8.1, and the consensus estimate is that the pH will drop to 7.8 by the end of this century.

Acidification has been the research focus of biological oceanographer Dr Debora Iglesias-Rodriguez with the National Oceanography Centre at Britain’s University of Southampton. She has researched how phytoplankton, which are the major contributors to sinking carbon in the oceans, are able to absorb carbon now and into the future when human impact on the atmosphere is changing the chemistry of the oceans and how this will affect the oceans ability to sink carbon in the future.

“The oceans are becoming more alkaline now and this will affect marine life and marine animals and plants,” Iglesias-Rodriguez told Al Jazeera. “The chalk producing calcifying organisms are introducing chalk into these increasingly acidic conditions, and it is dissolving.”

These chalk produced by these organisms traps and stores carbon, so when increasing acidification decreases the amount of calcium carbonate, it decreases the ocean’s ability to store carbon.

“Calcification affects fisheries because many fish’s diet is based on these organisms, so this has food security impacts as well,” added Iglesias-Rodriguez. “The changes we are seeing now are happening faster than they have for 55 million years. The worry is that these organisms may not be able to keep up with these changes.”

In this kind of environment, shellfish cannot produce thick enough shells. By 2009, the Pacific oyster industry was reporting 80 per cent mortality for oyster larvae due to the corrosive nature of the water.

“Acidification has the potential to change food security around the world, so I think it’s incumbent upon the entire world to recognise this and deal with it,” Cooley told Al Jazeera.

Cooley said that less developed countries that are more dependent on seafood will have less to eat as acidification progresses, and they will be forced to migrate somewhere where there is a better food supply.

Further complicating the situation, rising sea levels, also caused by climate change, will affect migration patterns from island nations as well.

In addition to food security issues, increasing acidification will also cause coral reefs to be degraded, which will affect tourism, coastal protection, and heritage values of coastal regions.

Prof Matthias Wolff is a fisheries biologist and marine ecosystem ecologist working for Leibniz Centre for Tropical Marine Ecology, as well as a research professor and professor at university of Bremen, Germany.

“Plankton, organisms that produce much of the carbon in the sea and coral, are dying off,” he told Al Jazeera. “So people believe that CO2 level may double from the pre-human times to more than 400-500 ppm by the end of the century, which would be a unique situation in history. This would have a tremendous effect on these organisms that would affect the whole ecosystem.”

Cooley points out that while some species will benefit from increasing acidification, others like corals and molluscs will suffer, along with others that are pH sensitive that cannot control their intercellular biology as well.

“We think there will be shifts in ecosystems, and the current array of species present in an ecosystem is going to shift and there will likely be a new dominant species,” she said. “Past studies have shown us that any real decrease in species in an ecosystem can be a bad thing. On land, we see that monoculture fields are really susceptible to a virus or bug. So if acidification decreases diversity, it creates a less stable system in the future. We’re anticipating, if things go as they are going now, we really could be seeing some profound shifts in what we know and what we currently benefit from.”

Myriad problems

In addition to climate change and acidification, there are many other problems that concern scientists as well.

“Marine pollution, this is a big issue,” Dr Iglesias-Rodriguez said, “There is this idea that oceans have unlimited inertia, but the effect of nano-particles of plastic getting into marine animals and the food chain and these are affecting fish fertility rates, and this effects food security, and on coastal populations. Pollution is having a huge impact on the oceans, and is urgent and needs to be dealt with.”

Dr Nichols describes the crisis of the oceans as a three-fold problem.

“We’re putting too much in, in all forms of pollution, we’re taking too much out by fishing, overfishing, and bi-catch, and we’re destroying the edge of the ocean - these places where there is the most biodiversity like reefs, mangroves, sea grass, etc.”

Nichols said he finds plastic on literally every beach he visits across the globe, and added, “Probably every sea turtle on the planet interacts with plastic at some point in its life.”

Nichols believes that, rather than the polar bear, sea turtles should be the “poster species” for climate change.

“The sex of sea turtles is temperature dependent, so as temperature warms more males are produced, cooling produces more females, and obviously you need the right mix to maintain numbers,” he explained, “We’re seeing some eggs literally cooking on beaches now because the temperature has moved out of the tolerable range.”

Prof Wolff explained another issue complicating the situation.

“The oceans warm up, and this affects spatial distribution of fish,” he explained, “Those needing colder waters need to migrate and change the distribution, other fish can extend their distribution greatly when the water warms, so now they can reach polar regions where they weren’t before. So there is a great change in distributional patterns of the resources of the fisheries to be expected in the future.”

Wolff points to Greenland fisheries as an example of how an area warms up, there are longer periods for fish production, while in other areas like Brazil and Indonesia, productive areas are shrinking and there will be a great decrease in fishing potential.

“This is already happening,” said Wolff.

Dr Knowlton is concerned about how increasing ocean temperatures are causing the bleaching of coral reefs.

“Bleaching causes a lot of problems for corals, because if it’s severe and prolonged the algae starves to death because the amount of nutrition coral needs is not there,” she said. “The 1998 El Nino bleached 80 per cent of the corals in the Indian Ocean and 20 per cent of them died.”

She is concerned by the fact that high temperature events like the 1998 El Nino are becoming increasingly common, and added, “We’ve been having bleaching for close to 30 years now.”

Like others, Knowlton sees poor water quality from pollution, overfishing and other problems that are causing ocean conditions to become increasingly unfavourable for corals.

She believes if there is not a major shift to correct the pollution problem, the next 10 years are going to be bleak.

“Increasing numbers of dead zones and collapsing fisheries,” Knowlton says is what we can expect, “Then ultimately the collapse of these deep ecosystems that are dependent on things like coral reefs.”

What to do?

Despite these grave concerns, Knowlton feels there is something that can be done.

“Even though the long term prognosis with business as usual is pretty grim, we know there are smaller areas where reefs are protected and those are very healthy, and we can reduce local stresses and that builds resilience in ecosystems.”

Prof Wolff pointed out that, while more than 75 per cent of fish stocks are overfished or already depleted, there are a number around the globe that are regenerating.

“In 2009 we saw that more than 50 per cent of overfished areas are being rebuilt because they responded to the situation of heavy over-exploitation, so I’m a little more optimistic than many other scientists. By reducing fishing, we can allow the stocks to rebuild.”

But he believes that in order for this to happen, we need to create more protected areas in the oceans.

According to Wolff, roughly 10 per cent of our lands are protected, but far less than 1 per cent of oceans are protected.

“We need to aim for 10 to 20 per cent of oceans being protected, because that is what is needed to maintain ecosystem functioning and to rebuild the stocks,” he said.

Wolff has been working in the Galapagos Islands on conservation, and cites them as an example of what can happen with protected areas, since there has been no fishery there since 1998.

“If you go diving there you see an abundance of large fish and sharks, which I’ve never seen anywhere else, you see 200 to 300 sharks in one dive,” he said. “To me, this is a promising example of the way we need to go. We need more money for this than for subsidies for fisheries, which is ridiculous. Right now, they are getting as much money as we’d need to manage protected areas of 15 per cent of the oceans.”

Nichols believes it is no longer about trying to avert disaster, but more along the lines of mitigating the problems that are already upon us.

“I think we’re in it right now,” he said, “So it’s not about, here’s how much time we have. The clock in many ways has already run out. We’re still growing our use of fossil fuels, we’re not even in a mode of trimming them down, same with our use of plastic and the plastic pollution generated from it. There’s more conversation about this than ever, but it’s not translating into societal change or evolution.”

Nichols makes his point by way of example of ocean types.

“If ocean 1.0 is the pristine natural ocean, 2.0 is the ocean we have now under the petroleum product regime of 100 years of use, and 3.0 is the future ocean,” he said. “It can either be a dead ocean, or we can come up with some very innovative solutions that right now people aren’t even talking about.”

He said we can come up with new ways of getting food from the oceans that don’t involve long line fishing and bottom trawling, as well as eliminating packaging and taking a zero-waste approach to consumer goods, both of which he says are possible, “if we can muster the political and personal motivation.”

“We could have a healthy ocean in 50 years if we make some bold moves, it wouldn’t be 1.0 or 2.0, but it would be a cleaner from a more responsible set of actions for how we get energy from the oceans and how we use them as a source of food.”

If that is not done, then we most likely will face a future predicted in a 2008 report co-authored by NASA’s James Hansen, a leading climate scientist, titled, Target Atmospheric CO2: Where Should Humanity Aim?

“Humanity today, collectively, must face the uncomfortable fact that industrial civilisation itself has become the principal driver of global climate,” reads the report, “If we stay our present course, using fossil fuels to feed a growing appetite for energy-intensive lifestyles, we will soon leave the climate of the Holocene, the world of prior human history.

The eventual response to doubling pre-industrial atmospheric CO2 likely would be a nearly ice-free planet, preceded by a period of chaotic change with continually changing shorelines.”

 

Source: https://www.aljazeera.com/indepth/features/2011/11/2011111653856937268.html