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The ocean – large, complex, not well understood, and changing rapidly: a big problem as we seek to understand global environmental change.


Recent articles in the technical journals and in the media convince me we should be getting a lot more concerned about the state of the ocean than we are. Sure there has been progress. IPCC devotes whole chapters to discussion of ocean phenomena, numerous reports have appeared calling for more attention to the ocean, and oceanic processes are increasingly invoked to explain observed changes in climate. But I was prodded to attention when calls appeared earlier this month in both Science and Nature, urging the commencement of carefully controlled experimentation on possible geo-engineering solutions to the problem of global warming.

In their ‘comment’ in Nature, Jane Long, formerly of Lawrence Livermore National Laboratory, and two equally senior US colleagues, called for the US government and others to begin programs to fund small-scale, low-risk, outdoor, climate-engineering research, and develop a framework for governing it. They argued that it was important to grow the science and the regulatory framework together, and to commence now, before rogue operators do something the world will regret. Their assumption, of course, is that US science and US scientists would not do anything reckless.

Science reported in its 13th February issue that the US National Research Council (NRC) has recommended that the US government commence funding for a coordinated program of research on albedo modification and on atmospheric carbon removal technologies. The article does not mention the risk of rogue operators, but talks instead of the likely need for such techniques “to avoid the worst impacts of climate change”, and the reluctance of funding agencies until now to fund such research. This article also reports that the NRC study was requested and partially funded by the CIA.

Geo-engineering is the term used to cover engineered or technological fixes for climate change and other environmental problems, and geo-engineering has its cheerleaders. Using geo-engineering, we invent our way out of difficulties rather than correct behavior that over-taxes the planetary systems. Many of those in favor of geo-engineering are the same people who believe we can establish colonies on the moon, or replace natural systems on this planet entirely with engineered ones. They believe we already understand environmental systems sufficiently to build a world where we can do what we want to do even if that includes exceeding currently existing limits set by the natural planetary system. They seek to bend the planet to our will rather than operate in ways that sustain the planet. They are definitely rah-rah engineers rather than scientists. We saw one, not too long ago, bilking First Nations people out of millions by promising to fertilize the oceans around Haida Gwai.

Albedo modification is a term used for various technological approaches to cooling the Earth, usually by making the atmosphere more reflective thereby reducing the amount of sunlight reaching and warming the planet. Most techniques involve polluting the atmosphere with small particles or molecules of some type. Carbon removal refers to approaches that would suck carbon, or CO2, out of the air for sequestration deep underground or elsewhere. Geo-engineering fans see these as obvious solutions to present problems. The problem is that any exploration of such approaches outside a lab necessarily makes use of our shared environment. Experiments are experimental – they can go badly wrong. I would much prefer carefully regulated research to rogue experiments in any science done outside the laboratory, but I am also concerned that the enthusiasm for research in this area, well regulated or not, smacks too much of an ‘if we build it they will come’ mentality that guarantees the upscaling and use of these approaches to managing climate whether or not other solutions are available. How much better to solve our CO2 pollution by adding commercial air pollution with reflective particles, than to reduce our problematic CO2 emissions? It becomes a new, money-making activity, and allows us to continue our profligate polluting ways.

At the same time, I am concerned that our very slow progress towards CO2 emissions reductions may well leave humanity exposed to an ugly climate in the near future, one that is so bad it must be improved temporarily using some geo-engineering strategy because the real fix (reductions in emissions) is taking too long. While they express it differently, authors of both recent articles share this concern. Indeed, the NRC report takes pains to discriminate between albedo manipulation and carbon removal, and lead author, Marcia McNutt referred to albedo manipulation as “really scary” and something to do our best to avoid. Nevertheless the report sees starting some well-regulated geo-engineering research as sound insurance.

In my view, the correct approach, difficult though it may be, is to put in place an international, enforced moratorium on any albedo manipulating experiments while continuing to encourage approaches for carbon capture and storage (CCS), and to work hard for the international agreement on reducing CO2 emissions that we all know we must have. It is the right approach because you do not solve pollution by creating additional pollution, and because you do not achieve difficult political agreements by reducing the pressure to agree. It is also the right approach because adjusting the planet’s albedo only addresses the warming due to addition of CO2 to the atmosphere – it totally ignores the impacts of all that added CO2 on the world’s ocean. We cannot afford to forget about the health of our ocean and proponents of geo-engineering frequently do.

The Ocean – most important ecosystem on the planet – is changing

The ocean is a massive yet moving heat sink that both stores immense quantities of heat and moves heat from the tropics toward the poles. Covering about 70% of the planet’s surface, and containing 13.7 billion km3 or 97% of the planet’s water, the ocean is enormous and the major heat sink on the planet. The ocean has absorbed about 93% of the excess heat entering the Earth system over the last 45 years, and about 30% of the CO2 which we have been emitting into the atmosphere.

Most of that heat remains in the upper 700 m of depth, which has warmed most appreciably in recent years. Some of this heat has diffused to deeper layers and there is now measurable warming down to about 2000 m depth. Below that depth, temperature has not increased significantly in recent years. Part of the reason for this is that the ocean is only slowly mixed vertically via the giant ocean conveyor system which operates on time-scales measured in hundreds to thousands of years. Surface warming has strengthened the stratification of surface layers, further limiting vertical mixing and heat diffusion.

Fig 3.18 IPCC WG1AR5 pH changes

Figure 3.18 from the IPCC Working Group I Report, part of their 5th Assessment Report, 2013. Plots show similar trends through time in [CO32-], pCO2, and pH for surface waters at Bermuda (BATS), Hawaii (ALOHA), and in the north-east Atlantic (ESTOC). At all sites, CO2 has been increasing while pH and CO32- have been declining. Image © IPCC.

The same slow mixing is responsible for most of the CO2 absorbed in recent years remaining in the upper layers. It is in these surface layers that increased CO2 is causing a decline in pH, which has fallen about 0.1 unit since the beginning of the industrial era. Present-day surface water pH ranges regionally from 7.8 to 8.4 (average about 8.1). The link between CO2 and pH concerns the chemical equilibrium of ions of CO2 and CaCO3. Increasing CO2 leads to an increase in availability of CO32- and a decrease in HCO3. This decrease of 0.1 pH units represents a 26% increase in availability of H+ ions. On time-scales of 100 to 1000 years, the added CO2 will be distributed to deeper layers of the ocean, and on time-scales of 100,000 years, CO2 will be precipitated as CaCO3 sequestered into oceanic sediments.

Whether being warmed and carbonated or not, the ocean basin-scale circulation pattern termed the giant ocean conveyor transports heat and salinity away from the tropics in surface flows which tend to cool and sink beneath now less dense, less saline polar waters. There is some concern among ocean scientists, but little direct evidence so far, that changes in surface water temperatures, and rates of melting of ice may act to slow this ‘turnover’ between surface and deeper waters by slowing down the ocean conveyor.

As well as being an important storehouse for heat and CO2, the ocean has immense biological importance. Photosynthesis by marine phytoplankton currently rivals that of terrestrial vegetation in production of organic matter, and in release of oxygen to the atmosphere. Changes that reduce the effectiveness of phytoplankton would have major, and long-term, impacts on food production and on oxygen concentration in our atmosphere.

In a major review of the complexities of the microbiota of the marine plankton, Alexandra Worden of the Monterey Bay Aquarium Research Institute (MBARI), and five colleagues from MBARI, MIT, University of British Columbia, and Oregon State University, recently drew attention to the enormous variety of types of organisms represented in the marine plankton.

Their paper, in the 13th February issue of Science, pointed out that the huge diversity of lifestyles among the protists in particular made any presentation of the single-celled plankton as ‘photosynthetic’ far too simplistic. Their paper, an ode to the rich, and as yet poorly understood biodiversity of these smallest of oceanic species, included a fascinating diagram representing all of eukaryotic (non-bacterial) life on our planet. That we understand so little of so many of these types of organism, and that the marine plankton is rich in representatives of all seven major and many of the sub-groups in their diagram, must give us pause when we consider likely impacts on the ocean’s biological capacities of our additions of CO2. Perhaps we should all take a look at their diagram once a week as a way of instilling humility, and driving out the hubris that leads to simplistic notions of being able to geo-engineer our way out of the problems our CO2 emissions are creating for us.

Worden Science ocean plankton F3.large

Figure 2 from Alexandra Worden’s review. Single-celled protists of many types are well represented in every one of the seven major branches of the eukaryote tree of life, and representatives of all seven groups make up the marine plankton. We are located along with all the rest of the ‘higher animals’ (Bilateria), alongside the Cnidarians (corals), Ctenophores (comb jellies), and Porifera (sponges), within the Opisthokonts. Fungi are another type of Opisthokont, and mosses and green plants are among the Archaeplastids. This tree omits all the prokaryotes that are even more numerous.
Image © Science.

Although it came out a month earlier, the article in Nature Climate Change for January 2015, by Phillip Boyd of University of Hobart, Australia, and colleagues from Woods Hole Oceanographic Institution, USA, and Braunschweig Technical University, Germany, provides a nice reinforcement of Worden’s primary message that we do not yet understand oceanic biology well. Boyd and colleagues demonstrate that there is significant regional variation in the strength and direction of trends in various aspects of ocean condition (temperature, salinity, pH, concentration of certain nutrients) being caused by our CO2 emissions, and that these differing patterns of overall change are going to impact different members of the plankton in different ways. They suggest the responses to some variables range from shifts of 20% to 300% in various physiological rates. Numerous interactions will occur among species that are more or less favored by the changed environment. Yet another set of voices arguing for caution when evaluating the likely effects on primary oceanic processes when we consider the changes we are causing.

And it’s not just climate change

Our impacts on the ocean are numerous. I won’t even waste space here talking about our over-fishing. Nor will I say anything about our ocean pollution. Other than to point out that in mid-February, Science published the most up-to-date estimate of the amount of plastic waste that gets to the ocean. The paper by Jenna Jambeck of University of Georgia, and six colleagues from across the US (plus one from CSIRO, Australia), indirectly calculated amount of plastic waste entering the oceans by first estimating amount of solid waste produced, extent to which that waste was plastics, and the effectiveness of waste management for each of 190 countries. The proportion of waste production that was within 50km of a coast was used to estimate the extent of the mismanaged waste in each country that would likely end up in the oceans.

Jambeck and colleagues calculated that in 2010, 192 countries generated 275 million Mt of plastic waste, and that between 4.8 and 12.7 million Mt of this entered the oceans. That’s somewhere between 4 and 12 million metric tonnes of it! Their estimate is one to three orders of magnitude greater than the mass of plastic reported to be floating in oceanic gyres (about 50 to 60% of plastic waste produced would be buoyant). While the discrepancy is large, the quantities of plastic waste they calculated are reasonable given the amount of plastic resins being manufactured. Jambeck and colleagues also report they expect the amount of plastic waste produced to increase an order of magnitude by 2025 as economies and standards of living grow. They include a table of the top 20 countries in terms of quantity of mismanaged plastic waste per year which shows large variations in quantity of waste, effectiveness of waste management, and per capita rate of waste generation. Not surprisingly, China tops the list. Its huge population mismanages 8.82 million Mt of plastic waste per year, while that of the US, 20th on the list, mismanages 0.28 million Mt per year. On the other hand, per capita, Americans generate 2.58 kg plastic waste per day, while the Chinese generate just 1.10 kg per day. While lots of plastic waste forms unsightly flotsam, or entangles iconic marine creatures, the greatest damage to the oceans happens at far smaller spatial scales where minute marine zooplankton and larval fish ingest micro-particles (a recent article is available here).

I blogged earlier this month about the paper in Science by Doug McCauley and colleagues suggesting that marine defaunation is likely to proceed rapidly as we continue to intensify our use of the oceans. They detail the many ways we are impacting marine life, and the many ways in which marine systems currently provide important goods and services for us.

And our ocean modulates our climate

Just as our changing climate is changing the ocean, the ocean modulates our climate. The warming effects of our CO2 pollution would have been far more severe if the ocean was less able to absorb heat. And yet, the complexity of ocean dynamics continues to make it quite difficult for us to comprehend exactly how it acts on climate, or to anticipate how it will act on climate in the future.

Just this week, Byron Steinman, of U. Minnesota, Duluth, with Michael Mann and Sonya Miller of Penn State, reported additional details in Science of the relationship between large-scale, multi-decadal oscillations in sea surface temperature in the North Atlantic (AMO) and North Pacific (PMO) and northern hemisphere temperatures. The so-called pause in warming since about 2000 (‘so-called’ because while the atmosphere has warmed more slowly, the oceans have continued to warm in response to our continued emissions of CO2) has been argued about ad nauseum ever since denialists first grabbed onto it as the latest proof that climate was not changing. Over the past several years, there has been a series of reports by various scientists filling in the gaps in knowledge of the oceans, and this paper is the latest. Steinman and colleagues show that we have been going through a period when the AMO was in a modestly positive phase while the PMO was in a strongly negative phase. The result is that air temperatures in the Northern Hemisphere have been cooler than they might have been. The expectation is that quite soon, the PMO will shift more positive and atmospheric warming will pick up noticeably.

Meanwhile, with warmer sea surface temperatures, and with a warmer Arctic causing the jet stream to slow and wobble, eastern North America has seen another bruising February, and record snowfalls in many locations. The Thinkprogress blog had a nice piece on our interesting winter. Despite a warming world, those of us in eastern North America may have to become used to a shorter, but more intense winter, at least for a while.


Sean Davey Aurora Photos surf-waves-adventure_22958_600x450

If we understand the ocean, we can work with it. If we take it for granted… Photo © Sean Davey/Aurora

Putting all these things together, I think we should be far more appreciative of our ocean, far more aware of all the things it does for us, and far more concerned about the things we are doing to it. Our changes to CO2 concentrations have already set in train oceanic processes that will continue for thousands of years as heat and carbon are redistributed about the ocean. The acidification alone may have major biological repercussions, as may our plastic pollution and all the other types of pollution we spill into the ocean. The reduction or loss of services as fundamental to life as the production of atmospheric oxygen are not outside the realm of possibilities, and we really need humility as we work to increase our understanding of just what we are doing.

News Flash – China is colonizing the high seas

Nothing to do with this week’s topic except it definitely concerns the ocean: China has for some time now laid claim to the Spratly Islands, an archipelago of some 750 reefs and cays in the South China Sea.

Spratly Islands Google Map

This screengrab from Google Maps shows the Spratly Islands close to the Philippine island of Palawan, and also closer to Viet Nam and Maylasia than to China. Nevertheless, China claims them. Map ©

China’s interest, and indeed that of the Philippines, Malaysia and Viet Nam, has to do with the fisheries in these productive waters, and perhaps also with likely oil and gas reserves. However, China has recently upped the ante, with extensive island building. Borrowing the destructive techniques pioneered in the Arabian Gulf by the Dubai builders of Palm Jumeirah and The World, islands are being created on top of reefs, by dredging with no effort to contain sediment or siltation.

Now, it is true that most of the other claiming nations have also established outposts from time to time on one or more of the few small sand cays that are the only land. But building islands where no land previously existed, and islands big enough for runways and wharves; that is different. There is an excellent series of aerial photos here, and the Los Angeles Times provides a good account.

Ironic fact is that the building approach is not one that is compatible with continued sustainable management of productive reef waters. This is a blatant grab of high seas territory. Not only do we not understand the ocean, behavior such as this shows we do not respect it.