Monday, Jun 23, 2014 01:30 AM +1000

How Rupert Murdoch created the world’s newest climate change villain

Australia was once a leader on climate action. Thanks to American conservative powerhouses, that’s no longer true

Alexander White

Topics: Rupert Murdoch, Climate Change, Global Warming, Australia, Tony Abbott, Grover Norquist, Conservatism, Climate deniers, Sustainability News, News, Politics News

Tony Abbott, Rupert Murdoch (Credit: Reuters/Dinuka Liyanawatte/Lionel Bonaventure/Photo montage by Salon)

Australia, the sunburned country, is uniquely vulnerable to the dangers and risks of global warming. Whether it is the severe effects of flooding, unseasonal heat waves, devastating bush fires or decade-long droughts, Australia’s people, economy and natural environment have all keenly felt the impact of extreme weather and climate change.

Australia’s national scientific organizations have been raising the alarm for more than a decade, and the previous government accepted that scientific consensus and enacted a cap-and-trade scheme in 2012. But after a divisive election last year — one that saw native-born Rupert Murdoch exercise his considerable influence in Australian media markets to disastrous effect — the country is now governed by a deeply unpopular Liberal-National government, crafted in the image of the most climate-denying elements of the Tea Party. And its position on climate change has significant impacts on global efforts to reduce carbon emissions: Australia is not only the chair of the G-20 group of nations, but also holds a place on the U.N. Security Council.

The rest of the world saw this ideology on full, embarrassing display with the recent visit by Prime Minister Tony Abbott to Canada and the United States. A week after President Obama’s introduction of substantial policy reforms to reduce carbon pollution, and China’s first-ever pledge to cap carbon emissions, the Australian prime minister stood next to his Canadian counterpart and scoffed at the idea of global warming, saying that climate change is “not the only or even the most important problem that the world faces” and that measures to reduce carbon emissions would “clobber” the economy.

All of this marks a shift for Australia, from constructive middle-power to fringe-dwelling rock-thrower and -blocker. Back at home, Tony Abbott is on course to make Australia the first nation in the world to abolish a legislated carbon price.

But how on earth did this happen?

The calm before the storm

Global justice, sustainability and the sharing economy

If the sharing economy movement is to play a role in shifting society away from the dominant economic paradigm, it will have to get political. And this means guarding against the co-optation of sharing by the corporate sector, while joining forces with a much larger body of activists that have long been calling – either explicitly or implicitly – for more transformative and fundamental forms of economic sharing across the world.

With public interest in the sharing economy on the rise, a polarisation of views on its potential benefits and drawbacks is fast becoming apparent. Much of the mainstream media continues to focus on the ability of the sharing economy to generate wealth and create new billionaires, while some social entrepreneurs and progressives claim that interpersonal sharing is the solution to the world’s most intractable problems. At the same time, a growing number of analysts are concerned that the sharing economy could enable businesses to evade regulations and even break the law. These increasingly conflicting views reflect the diverse interests of the many individuals, organisations and businesses engaged in what is essentially an emerging movement for sharing that has yet to clarify its purpose.

To add a further layer of confusion to the debate, there is little agreement on what the sharing economy actually is. For example, Rachel Botsman – a leading proponent of the ‘what’s mine is yours’ philosophy – argues that the sharing economy forms part of a much wider collaborative economy that leverages technology and trust to facilitate a more efficient distribution of goods and services. A broader definition has been put forward by The People Who Share, who regard the sharing economy as an “alternative socio-economic system which embeds sharing and collaboration at its heart – across all aspects of social and economic life”. Friends of the Earth have also significantly expanded the discourse on sharing to include the political sphere, albeit focussing on city-wide sharing as a means for improving environmental sustainability and equity among citizens.

All of these existing definitions still pay insufficient attention to national and global forms of economic sharing, particularly those facilitated by democratically elected governments. Instead, the focus generally remains limited to individual (peer-to-peer) and local sharing initiatives. Apart from those advocating for localised forms of sharing to be replicated in cities across the world, rarely is the sharing economy discussed in terms of systems of sharing and redistribution that operate on a nationwide or global scale, or in relation to calls for governments to institute the more transformative forms of economic sharing that are possible today.

This is not to deny the very real potential of the sharing economy to help strengthen communities, reduce the rate at which resources are consumed, and create financial returns at very low marginal cost. However, if our reason for supporting different modes of sharing is a desire to create a more equitable and sustainable economic system, we need to significantly broaden our understanding and interpretation of what constitutes a sharing economy. There is no question that it makes sound economic and environmental sense for businesses and individuals to reduce their carbon footprints and share scarce resources. But government policy (enacted either nationally or through international agreements) ultimately determines how effectively nations and the international community can address the underlying causes of inequality, climate change and resource wars – some of the most pressing challenges that face humanity in the 21st century.

Bearing in mind the urgent need to implement sharing on a systemic and global basis, a fresh evaluation of the sharing economy from the perspective of social justice and environmental sustainability is presented below. The five general positions that follow do not present a comprehensive critique by any standards, but they are a starting point for broadening the sharing economy discourse and making it more relevant to the bigger picture issues that concern many progressives today. In particular, this perspective questions the role of commerce in so-called sharing-related business activities. It also proposes that we should include longstanding national and global forms of sharing in our definition of what constitutes a sharing economy, especially if we are working towards the creation of a more equal, just and sustainable world.

Interpersonal forms of sharing are not enough to deliver social justice or environmental sustainability

There is good reason to doubt whether the sharing economy (at least as it is generally understood today in terms of peer-to-peer activities) can ever have a significant impact on pressing global crises. For example, many people involved in the sharing economy aim to reduce their personal consumption to sustainable levels. While this is an important practice, the sheer scale of the ecological crisis suggests that simply sharing surplus or under-utilised personal goods is not a sufficient response to a global problem that requires systemic change at all levels to resolve. As often repeated, humanity as a whole is consuming natural resources 50% faster than the planet can replenish them. Not only is this massive overshoot in global consumption levels set to worsen as the world’s consumer class expands, it is also further complicated by huge imbalances. Around 20% of the world’s population are responsible for 80% of all resource consumption, while the remaining 80% are surviving on a ‘low consumption pathway’ and 20% are in ‘basic needs deficit.’

Clearly the global sustainability crisis cannot be addressed effectively until the structural factors that are responsible for creating these inequalities are fully addressed, and this has huge implications for transforming government policies and economic systems both nationally and globally. A huge array of reforms are needed to reconfigure the way nations extract, produce, distribute and consume resources across the world. For instance, this would include rethinking our notions of progress and prosperity, ending the dominance of consumption-led economic growth over government policy, and reversing the relentless push towards trade liberalisation. Much also needs to be done to dismantle the culture of consumerism, reconceptualise financial measures like GDP, and shift investment towards building and sustaining a low-carbon infrastructure, as endlessly debated by civil society.

In fact, the entire ecological conundrum is increasingly being framed in terms of sharing by progressive analysts – either through an ‘equity and fair shares’ lens or from the perspective of sharing the planet’s resources more sustainably to secure basic human rights for all. Although these critical discourses on sharing are becoming ever more urgent and popular among civil society thinkers, sharing economy advocates have generally neglected these systemic issues and failed to connect with environmentalists and anti-poverty campaigners who are often calling for vital forms of global economic sharing.

The need for public sector-driven solutions is also evident in relation to tackling poverty and inequality which, in simple terms, requires governments to ensure universal access to essential goods and services. But instead of promoting or facilitating these fundamental aspects of economic sharing, most sharing economy supporters tend to focus on the collaborative (and often for-profit) sharing of household items, cars or spare rooms – not the resources that people most desperately need to be shared today such as nutritious food, healthcare and essential public services. Similarly, while sharing in terms of charitable giving and voluntary assistance within communities can help redistribute wealth and alleviate some instances of human deprivation, it cannot address the structural causes of poverty and inequality that have their basis in public policy.

If advocates of the sharing economy are really motivated to tackle complex social and ecological issues, they should also devote time and energy to promoting forms of sharing that are far more effective at addressing these problems, such as universal social protection or contraction and convergence approaches to addressing climate change. This means moving beyond the solely personal, community and city-oriented view of sharing, and embracing a wider understanding of sharing that includes the role of governments in advancing effective social policy and environmental regulations. Most of all, it is at the national and global level that the sharing economy can be revolutionary and transformative – if its supporters are willing to engage in the gritty politics of reforming government policy to establish truly effective and ‘sharing’ societies.

A much broader definition of the sharing economy is needed

Existing definitions of the sharing economy tend to focus on personal, local and business approaches to sharing, even when those involved in the sharing movement profess to care deeply about climate change and other global issues. But these definitions present a very limited and superficial understanding of what the sharing economy is, which disconnects the sharing economy movement from serious attempts to address social injustice or environmental degradation. For instance, national systems of sharing are arguably the most established, important and fundamental examples of sharing economies that exist in the modern world, as alluded to above. Through systems of progressive taxation and the provision of essential public services and social protection for all, the vast majority of people in most developed countries are involved in and benefit from these broad-based sharing systems. Why aren’t these crucial examples of sharing part of the discourse and evolving definition of the sharing economy?

Perhaps a majority of those involved in the sharing economy come from an entrepreneurial or technology background, and therefore prefer to focus on social enterprise solutions or software-driven and online peer-to-peer platforms. Others might be deeply sceptical about state intervention and regulation – a view that is particularly prominent in the United States. Or perhaps, as various commentators are increasingly suggesting, the sharing economy is more concerned with profit and the private sector than it is with the ethic of sharing per se. It stands to reason that if the sharing economy movement had a more robust focus on the welfare of people and the planet, one would expect more vocal opposition to austerity measures or greater support for environmental campaigns by organisations like Greenpeace – issues that are rarely if ever mentioned on the pages of the most prominent sharing economy websites. In this sense, the millions of people across the US and Europe who are mobilising against government austerity policies could be considered the real champions of the sharing economy.

In some cases, focussing on new sharing economy platforms, technologies and initiatives could even undermine more effective and established systems of national sharing. For example, while car sharing schemes are clearly good for the environment, a universally accessible public transport system is undeniably better. Indeed public transport can be regarded as a greener citywide or nationwide sharing platform – but few people promoting the sharing economy are advocating to improve such services. The intense focus that the sharing economy places on individuals and the private sector might also explain the recurring issues around sharing-oriented businesses flaunting regulatory and licencing conventions designed to protect society at large.

If a key focus for the sharing economy movement is on resolving global crises, it stands to reason that our understanding and definition of the sharing economy must include critical forms of sharing resources on an international basis that urgently need strengthening and scaling-up. Sharing resources on a finite planet, almost by definition, must take place globally and between governments. Even though international mechanisms for sharing are still in their infancy compared to the national systems of sharing mentioned above, some examples do already exist. These include essential forms of global redistribution such as humanitarian aid; emergent systems of global governance (as ineffectual and biased as they currently are); and frameworks and agreements that facilitate the protection and sharing of the planet’s scarce natural resources. This international aspect of sharing is the most crucial with regards to social and environmental justice, although it still remains the least developed or discussed among proponents of the sharing economy.

Supporters of peer-to-peer sharing could help build a much stronger identity by recognising that their activities form part of these much broader and more fundamental sharing systems that operate at all levels of society. An inclusive working definition that can embrace the diverse national and international forms of sharing was put forward in STWR’s report Financing the global sharing economy, and is worth revisiting:

“The sharing economy is a broad term used in this report that encompasses the many systems of sharing and redistribution that exist locally, nationally and globally – whether facilitated by individuals, states or other institutions. It is concerned with the social, economic, environmental, political and spiritual benefits of sharing both material and non-material resources – everything from time and love to money and natural resources.”

“In comparison, the global sharing economy refers specifically to systems of sharing and redistribution that are international or global in nature – whether facilitated directly by people and governments or by global institutions like the United Nations. It refers to the many methods by which the international community can share their financial, technical, natural and other resources for the common good of all people. The global sharing economy is still in its infancy, but is nonetheless an important expression of the growing sense of solidarity and unity between people and nations.”

The sharing economy movement must resist co-optation by the corporate sector

In a worrying phenomenon sometimes described as ‘sharewashing’, commercial activities that have never before been regarded as sharing are now re-branded under this trendy new meme. For example, most people would agree that renting is not the same as sharing and neither is giving people a lift in your car in exchange for cash. Room sharing and car sharing enterprises might offer excellent and rewarding services in their own right, but they may have little to do with the principle of sharing in relation to human rights and concerns for equity, democracy, justice and sustainability, especially when the main beneficiaries are company shareholders and not customers or employees. It is already well recognised that many so-called sharing enterprises adopt business models and ethics that do not allow wealth, income or decision-making to be shared with their employees or customers to any significant extent.

Above all, we must guard against sharing-oriented initiatives from being co-opted by the corporate sector. Rampant commercialisation is at the heart of the social and environmental problems we face, so those involved in the sharing economy movement should be cautious about supporting large corporations whose wider business models and practices fail to embody the principle of sharing in any real sense. This sort of co-optation is a well-documented phenomenon in relation to social and environmental issues, with the ‘greenwashing’ of oil companies that supposedly pursue an ecological agenda, and the ‘whitewashing’ of unethical corporations through Corporate Social Responsibility programs.

If sharing is not to be co-opted by venture capital and the corporate sector, perhaps there should be a minimum criteria for any company that professes to be part of the sharing economy. At the very least, sharing economy businesses should be set up as not-for-profits or cooperatives, or else they should adopt business models that promote the triple bottom line of people, planet and profit. They must also pay their fair share of taxes, as this is a key part of the established and most important system of sharing that we have (yet) created.

Sharing is already a common cause for the global justice movement

Many supporters of sharing economy initiatives think that sharing is fashionable and trendy – a lifestyle choice – and that by sharing they are doing their bit to promote egalitarian or environmentally conscious ethics and values. But if the sharing movement is to play a role in shifting society away from the dominant economic paradigm and help to resolve global crises, it will have to get political. This means recognising that sharing economy advocates are part of a much larger body of people calling for more transformative forms of economic sharing in relation to pressing social and environmental concerns.

Millions of people across the world are already campaigning for economic and political reforms that embody the principle of sharing, although they don’t always use the term ‘sharing’ in their advocacy and activities. The sharing of wealth, power or resources is central to what progressives have long been calling for, and supporting these demands for social justice, peace and ecological sustainability is fundamental to affecting structural change on the scale that is now necessary. This means being more aware of the issues that environmentalists and activists campaign on, and explicitly aligning local sharing activities with their broader justice-based vision of economic and ecological sharing.

For example, as mentioned above, strengthening systems of progressive taxation and public services is essential at the national level – and this means opposing economic austerity measures and supporting nationwide systems of sharing. Campaigners are also calling for new mechanisms for sharing the global commons (including the atmosphere – a key issue in international climate change negotiations) as this is the only way to create a more sustainable and peaceful world. If we support the sharing economy in its broadest sense as outlined here, we need to support these and other sharing-related campaigns in their many and diverse forms.

The sharing economy is best promoted by appealing to intrinsic values

It is not hard to imagine how a process of sharing could theoretically play a key role in addressing multiple global crises, as genuine forms of economic sharing should result in a fairer distribution of resources for all people within planetary limits. However, there is a great deal of evidence to suggest that promoting the sharing economy as another way to supplement our income is likely to promote extrinsic values that will undermine efforts to create a more equitable and sustainable world. According to detailed studies, promoting intrinsic values that go beyond concerns about oneself are far more likely to encourage sustainable lifestyles than a focus on extrinsic values, such as personal financial gain. In other words, those who share because they are told it can help them make some spare cash are less likely to engage in other environmentally beneficial activities, compared to those who share out of purely environmental concerns.

Of course, there is nothing wrong with making some extra money or being motivated by extrinsic values. However, if our goal is to help address the world’s interconnected and intractable crises, the evidence suggests that our campaigning activities must remain firmly aligned to intrinsic values. This has huge implications for all those involved in promoting the sharing economy at a time when so much of the public discourse on sharing highlights the growth and success of certain businesses in predominantly monetary terms.

To conclude, there is little doubt that through the time-honoured act of sharing we can strengthen communities, reduce consumption and facilitate the non-monetary distribution of goods and services – and this can potentially help rebalance an economic system that is increasingly dependent on greed and hyper-consumerism for its continued success. But interpersonal sharing is not enough at a time when humanity is facing what can only be described as a global emergency that includes massive poverty and rising levels of inequality, climate change and the wider ecological crisis, as well as ongoing conflicts over the world’s dwindling natural resources.

The process of sharing can only play a transformative role in addressing these crises if we move beyond our egocentric understanding of the sharing economy, and embrace national and global forms of sharing that are facilitated by government bodies in response to urgent social and environmental needs. By being vigilant about how we promote and participate in the sharing economy, we can also guard against the pervasive influence of commerce as it seeks to expand into new markets in a last ditch attempt to preserve the status quo. And by working more closely with the many millions of campaigners and organisations across the world who recognise the transformative potential of economic sharing – whether this is explicitly or implicitly expressed – we can significantly strengthen our chances of establishing an ecologically viable and socially just future for all.

Photo credit: cogdogblog, flickr creative commons

• Lenore Taylor, political editor
• theguardian.com, Sunday 22 June 2014 07.04 AEST
• Jump to comments (234)

Australians overwhelmingly want the renewable energy target to be retained or even increased, as the Abbott government considers abolishing the incentive for new renewable projects.

Polling for the Climate Institute shows 72% of Australians want to keep or expand the renewable energy target (RET), which requires that 20% of energy is sourced from renewables by 2020.

This is slightly higher than the 69% who said they wanted the RET maintained or increased when the same questions were posed in last year’s poll, despite a strong campaign over the past year by industry groups and Coalition backbenchers arguing that the RET was increasing power prices.

Respondents were then told “opponents of the scheme say the RET is a subsidy that drives up electricity bills, while supporters say it has helped create jobs and has tripled Australia’s wind and solar energy since 2009”. 71% still thought it should remain at its current level, 20%, or be increased, even after hearing the arguments. Support was especially high among women, with only 7% wanting the RET decreased or abolished.

But government sources said the Abbott government is likely to “grandfather” the scheme after it receives the final report from its review of the program, led by businessman and self-professed climate sceptic Dick Warburton. This would see it deliver only about one third of the renewable power that was originally legislated – with bipartisan support.

The sources said the challenge now was to work out how this could be achieved in practice.

The Coalition went to the election promising to keep the RET, which underpins investment in energy sources such as wind and solar, but saying it would review the fact that the policy was exceeding its original goal of delivering 20% renewable energy by 2020 because of falling electricity demand.

As yet unreleased modelling for business groups including the Business Council of Australia, the Minerals Council of Australia and the Australian Chamber of Commerce and Industry has considered four options: leaving the RET as it is, reducing it to a “real” 20%, “grandfathering” it to allow only existing investments to continue, and abolishing it altogether.

In its submission, the Institute of Public Affairs think tank, which favours abolition of the RET, says the government has three options, abolition, “grandfathering” or reducing it to a real “20%”.

The RET is currently required to deliver 41,000 gigawatt hours of renewables by 2020 (which was 20% of what it was incorrectly estimated that the market would be). To deliver 20% of the current market this would have to be reduced to 33,000GWh. Grandfathering would deliver only 15,000GWh.

The poll also found that 76% of people think state governments should do more to provide incentives to renewable energy. Again the strongest support came from women (82%).

The poll was conducted for the Climate Institute by JWS research from May 16-20. The sample size was 1,145 and the margin of error is 2.9%.

Warburton, a veteran industrialist and the chairman of the Westfield Retail Trust, described his views on climate science in a 2011 interview on ABC in this way: “Well, I am a sceptic. I’ve never moved away from that. I’ve always believed sceptical,’’ he said. “But a sceptic is a different person than a denier. I say the science is not settled. I’m not saying it’s wrong. I’ve never said it’s wrong, but I don’t believe it’s settled.”

Arctic Sea Ice – Methane Release – Planetary Emergency

ANNOUNCEMENT: Governments must put two and two together, and pull out all stops to save the Arctic sea ice or we will starve.

Arctic sea ice

Next week, the White House will hear evidence from Australian scientist, Carlos Duarte, that the Arctic sea ice is on such a downward spiral that we may see a dramatic decline of sea ice over the next two years [1].  Evidence was given to the UK government last year from British scientists, Peter Wadhams and John Nissen, that we could see minimal sea ice by September 2015, simply extrapolating the sea ice volume trend [2].  Evidence from recent satellite images suggests that a record melt is in progress this year.  The plight of the Arctic was highlighted to MPs and the Met Office in a recent showing of the film “Chasing Ice” at the House of Commons, London [3].  The Arctic has recently become an issue in the European Parliament [4].

Weather extremes and food security

Research from US scientist, Jennifer Francis, suggests that the retreat of sea ice is causing a disruption of jet stream behaviour, producing weather extremes [5].  Evidence was given to the UK government last year that the weather extremes being experienced in the UK and elsewhere could be due to this disruption of weather systems as the Arctic warms relative to the tropics.  This evidence was reported by Robin McKie in the Observer, on 7th April in an article entitled: “Why our turbulent weather is getting harder to predict” [6].  The weather extremes from last year are causing real problems for farmers, not only in the UK, but in US and many grain-producing countries.  World food production can be expected to decline, with mass starvation inevitable.  The price of food will rise inexorably, producing global unrest and making food security even more of an issue [7].

Action required

Putting these two strands of evidence together, it is obvious that we face an ever worsening food crisis unless something dramatic is done straightaway to cool the Arctic and save the Arctic sea ice.  This sounds impossible, but can be done.  Our best chance of success in cooling the Arctic quickly involves cloud cooling techniques, such as being developed by engineers Stephen Salter in the UK and Aaron Franklin in New Zealand.  Franklin’s technique could be deployed almost immediately.
Rapid collaborative action is common-sense logic and therefore the morally and legally correct thing to do in protecting citizens, see UNFCCC, Article 3 [8].   It also presents a golden opportunity for reconciliation between all peoples and all communities through working together towards a common purpose: to save our planet for enjoyment by future generations.   There is no time to lose.

References

[1] http://au.news.yahoo.com/thewest/a/-/wa/16886947/professor-joins-fight-to-save-arctic/

[2] http://www.publications.parliament.uk/pa/cm201012/cmselect/cmenvaud/c1739-ii/c173901.htm

[3] http://channel.nationalgeographic.com/channel/a-night-of-exploration/episodes/chasing-ice/

[4] http://www.theparliament.com/latest-news/article/newsarticle/arctic-ocean-predicted-to-be-ice-free-by-2015/#.UXaQU0qINQJ

[5] http://e360.yale.edu/feature/linking_weird_weather_to_rapid_warming_of_the_arctic/2501/

[6] http://www.guardian.co.uk/uk/2013/apr/07/science-behind-britain-coldest-easter?INTCMP=SRCH

[7] http://www.financialsense.com/contributors/joseph-dancy/record-food-prices-will-likely-disrupt-energy-markets

[8] http://unfccc.int/essential_background/convention/background/items/1355.php

Ocean current

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The ocean currents.

 

Distinctive white lines trace the flow of surface currents around the world.

 

Animation of circulation around ice shelves of Antarctica.

An ocean current is a continuous, directed movement of seawater generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences, with tides caused by the gravitational pull of the Moon and the Sun. Depth contours, shoreline configurations and interaction with other currents influence a current’s direction and strength. A deep current is any ocean current at a depth of greater than 100m.^[1] A part of oceanography is the science studying ocean currents.

Ocean currents can flow for great distances, and together they create the great flow of the global conveyor belt which plays a dominant part in determining the climate of many of the Earth’s regions. Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude. Another example is Lima, Peru where the climate is cooler (sub-tropical) than the tropical latitudes in which the area is located, due to the effect of the Humboldt Current.

Function

Major ocean surface currents, (Source: NOAA)

A recording current meter

Surface ocean currents are generally wind driven and develop their typical clockwise spirals in the northern hemisphere and counter clockwise rotation in the southern hemisphere because of the imposed wind stresses. In wind driven current, the Ekman spiral effect results in the currents flowing at an angle to the driving winds. The areas of surface ocean currents move somewhat with the seasons; this is most notable in equatorial currents.

Ocean basins generally have a non-symmetric surface current, in that the eastern equatorward-flowing branch is broad and diffuse whereas the western poleward flowing branch is very narrow. These western boundary currents (of which the Gulf Stream is an example) are a consequence of basic fluid dynamics.

Deep ocean currents are driven by density and temperature gradients. Thermohaline circulation, also known as the ocean’s conveyor belt which refers to the deep ocean density driven ocean basin currents. These currents, that flow under the surface of the ocean and are thus hidden from immediate detection, are called submarine rivers. These are currently being researched using a fleet of underwater robots called Argo. Upwelling and downwelling areas in the oceans are areas where significant vertical movement of ocean water is observed.

The South Equatorial Currents of the Atlantic and Pacific straddle the equator. Though the Coriolis effect is weak near the equator (and absent at the equator), water moving in the currents on either side of the equator is deflected slightly poleward and replaced by deeper water. Thus, equatorial upwelling occurs in these westward flowing equatorial surface currents. Upwelling is an important process because this water from within and below the pycnocline is often rich in the nutrients needed by marine organisms for growth. By contrast, generally poor conditions for growth prevail in most of the open tropical ocean, because strong layering isolates deep, nutrient rich water from the sunlit ocean surface.

Surface currents make up about 8% of all the water in the ocean. Surface currents are generally restricted to the upper 400 m (1,300 ft) of the ocean. The movement of deep water in the ocean basins is by density driven forces and gravity. The density difference is a function of different temperatures and salinity. Deep waters sink into the deep ocean basins at high latitudes where the temperatures are cold enough to cause the density to increase.

Ocean currents are measured in sverdrup (sv), where 1 sv is equivalent to a volume flow rate of 1,000,000 m³ (35,000,000 cu ft) per second.

Surface currents

About 10% of the water in the world ocean is involved in surface currents, which are water flowing horizontally in the uppermost 400 meters (1,300 feet) of the ocean surface, driven mainly by wind friction. Winds drive currents that are at or near the ocean’s surface. These currents are generally measured in meters per second or in knots (1 knot = 1.85 kilometers per hour or 1.15 miles per hour).^[2] surface currents move water above the pycnocline, the zone of rapid density change with depth. The primary force responsible for surface currents is wind. Most of Earth’s surface wind energy is concentrated in each hemisphere’s trade winds (easterlies) and westerlies. Waves on the sea surface transfer some of the energy from the moving air to the water by friction. This tug of wind on the ocean surface begins a mass flow of water. The water flowing beneath the wind forms a surface current. The moving water “piles up” in the direction the wind is blowing. Water pressure is higher on the “piled up” side, and the force of gravity pulls the water down the slope – against the pressure gradient- in the direction from which it came. But the Coriolis effect intervenes. Northern Hemisphere surface currents flow to the right of the wind direction, because of the Coriolis effect. Southern Hemisphere currents flow to the left. Continents and basin topography often block continuous flow and help deflect the moving water into a circular pattern. This flow around the periphery of an ocean basin is called a gyre.

Seawater flows in six great surface circuits

Gyres in balance between the pressure gradient and the Coriolis effect are called geostrophic gyres, and their currents are called geostrophic currents. The geostrophic gyres are largely independent of one another in each hemisphere, because of the patterns of driving winds and the present positions of continents. There are six great current circuits in the world ocean: two in the Northern Hemisphere and four in the Southern Hemisphere. Five are geostrophic gyres: the North Atlantic gyre, the South Atlantic gyre, the North Pacific gyre, the South Pacific gyre, and the Indian Ocean gyre. Though it is a closed circuit, the sixth and largest current, known as the West Wind Drift (or Antarctic Circumpolar Current), is technically not a gyre since it does not flow around the periphery of an ocean basin. The West Wind Drift flows endlessly eastward (i.e., never deflected by a continent) around Antarctica, driven by powerful, nearly ceaseless westerly winds. While it might be assumed that the two gyres in the North and South Pacific (and the two gyres in the North and South Atlantic) converge exactly at the geographical equator, instead the junction of equatorial currents (referred to as the meteorological equator) lies a few degrees north of the geographical equator. The meteorological equator and the Intertropical Convergence Zone (the band at which the trade winds converge) are displaced 5º to 8º northward primarily because of the heat accumulated in the Northern Hemisphere’s greater tropical land surface area. Ocean circulation like atmospheric circulation, is balanced around the meteorological equator.

Classification for geostrophic currents

Boundary currents have different characteristics. Because of the different factors that drive and shape them, the currents that form geostrophic gyres have different characteristics. Geostrophic currents may be classified by their position within the gyre as western boundary currents, eastern boundary currents, or transverse currents.

Western boundary currents

The western boundary currents are the fastest, deepest, and narrowest of all geostrophic currents, and they transport an extraordinary volume of water. They are found at the western boundaries of ocean basins (that is, off the east coast of continents). These currents move warm water poleward in each of the gyres. There are five large western boundary currents: the Gulf Stream (in the North Atlantic), the Japan or Kuroshio Current (in the North Pacific), the Brazil Current (in the South Atlantic), the Agulhas Current (in the Indian Ocean), and the East Australian Current (in the South Pacific). The Gulf Stream is the largest of the western boundary currents. The western boundary of the Gulf Stream is usually distinct, marked by abrupt changes in water temperature, speed, and direction. They can move for surprisingly long distances within well-defined boundaries, almost as if it were a river. However, long, straight edges are an exception, not a necessary property of western boundary currents. The western edge of these currents is often clearly visible. That is to say, the water within the current is usually warm, clear, and blue often depleted of nutrients and incapable of supporting a variety of ocean life. By contrast, water over the continental slope adjacent to the current, is often cold, green, and teeming with life. Western boundary currents meander as they flow poleward. The looping meanders sometimes connect to form turbulent rings, or eddies, that trap cold or warm water in their centers and then separate from the main flow. For example, cold-core eddies form in the Gulf Stream, meandering eastward upon leaving the coast of North America off Cape Hatteras. Warm-core eddies can form north of the Gulf Stream when the warm current loops into the cold water lying to the north. When the loops are cut off, they become freestanding spinning masses of water. Warm-core eddies rotate clockwise, whereas cold-core eddies rotate counterclockwise. The slowly rotating eddies move away from the current and are distributed across the North Atlantic. Some may be 1,000 kilometers (620 miles) in diameter and retain their identity for more than three years. In mid-latitudes, as much as one-fourth of the surface of the North Atlantic may consist of old, slow-moving, cold-core eddy remnants. Nutrients may be brought toward the surface by turbulence in eddies, which can stimulate the growth of tiny marine plantlike organisms. Recent research suggests that eddies may also influence the seafloor by slowly moving abyssal storms, which can be inferred from ripple marks that have been observed in deep sediments.

Eastern boundary currents

Eastern boundary currents have properties that are nearly opposite of their western boundary counterparts. Eastern boundary currents carry cold water towards the equator; they are shallow and broad, sometimes more than 1,000 kilometers (620 miles) across; their boundaries are not well defined; and eddies tend not to form. Their total flow is less than that of their western counterparts. The current is so shallow and broad that sailors may not even notice it. There are five eastern boundary currents, each of which are at the eastern edge of ocean basins (that is, off the west coast of continents): the Canary Current (in the North Atlantic), the Benguela Current (in the South Atlantic), the California Current (in the North Pacific), the West Australian Current (in the Indian Ocean), and the Peru or Humboldt Current (in the South Pacific).

Transverse currents

Transverse currents are currents that flow from east to west and west to east, linking the eastern and western boundary currents. They are derived from the trade winds at the fringes of the tropics and from the mid-latitude westerlies. The trade wind-driven North Equatorial Current and South Equatorial Current in the Atlantic and Pacific each transport ~30 sv westward, and are moderately shallow and broad. Since the Pacific has a greater expanse of water at the equator and stronger trade winds than the Atlantic, the Pacific develops more powerful westward flowing equatorial currents, which causes the height differential between the western and eastern Pacific to be as much as 1 meter (3.3 feet). Also, as a consequence of transverse currents, Atlantic water across the isthmus of Panama is usually 20 centimeters (8 inches) higher, on average, than water across the isthmus of Panama in the Pacific.

Countercurrents and undercurrents

Equatorial currents are typically accompanied by countercurrents, which flow on the surface in a direction opposite to that of the main current. At the meteorological equator, there is a continuous rising of air and a lack of presence of persistent trade winds across the boundary to drive water to the west. As a consequence, there is usually a backward (eastward) flow of water (referred to as a countercurrent) exactly at the meteorological equator, or a bit north or south of the meteorological equator. Countercurrents can sometimes be undercurrents, which are countercurrents that exist beneath the water surface. Undercurrents have been found under most major currents. The Pacific Equatorial Undercurrent, also known as the Cromwell Current, flows eastward beneath the North Equatorial Current with an average velocity of 5 kilometers (3 miles) per hour at a depth of 100–200 meters (330–660 feet). It is about 300 kilometers (190 miles) wide and carries a volume equivalent to about half the Gulf Stream. It has been traced for more than 14,000 kilometers (8,700 miles), from New Guinea to Ecuador. The first undercurrent was discovered in 1951 in the central Pacific by Townsend Cromwell, a researcher employed by the U.S. Fish and Wildlife Service.

Wind-induced vertical circulation

The wind-driven horizontal movement of water can sometimes induce the vertical movement of water from the deep, cold, nutrient-laden water toward the surface (a process known as upwelling). Equatorial upwelling occurs in these westward-flowing equatorial surface currents. Upwelling is an important process because water from within and below the pycnocline is often rich in the nutrients needed by marine organisms for growth. By contrast, generally poor conditions for growth prevail in most of the open tropical ocean, because strong layering isolates deep, nutrient rich water from the sunlit ocean surface. The South Equatorial Currents of the Atlantic and Pacific straddle the geographic equator. Though the Coriolis effect is weak near the equator (and absent at the equator), water moving in the currents on either side of the equator is deflected slightly poleward. Water north of the equator veers to the right (northward), and water to the south veers to the left (southward). Surface water therefore diverges, allowing deep water to replace surface water. Most of the upwelled water comes from the area above the equatorial undercurrent, at depths of 100 meters or less.

Langmuir circulation

Winds that blow steadily across the ocean, and the small waves that such winds generate, can induce long sets of counter-rotating vortices (or cells) in the surface water, referred to as Langmuir circulation. These slowly twisting vortices align in the direction of the wind. It usually takes about an hour for a particle in a vortex to complete one revolution. Streaks of foam (or seaweed or debris), called windrows, collect in areas where adjacent vortices converge, while regions of divergence remain relatively clear. Langmuir circulation rarely disturbs the ocean below a depth of about 20 meters (66 feet). Langmuir circulation occurs within the surface layer, which is above the pycnocline, and thus does not cause upwelling.

Thermohaline circulation

Coupling data collected by NASA/JPL by several different satellite-borne sensors, researchers have been able to “break through” the ocean’s surface to detect “Meddies” — super-salty warm-water eddies that originate in the Mediterranean Sea and then sink more than a half-mile underwater in the Atlantic Ocean. The Meddies are shown in red in this scientific figure.

Horizontal and vertical currents also exist below the pycnocline in the ocean’s deeper waters. The movement of water due to differences in density as a function of water temperature and salinity is called thermohaline circulation. The whole ocean is involved in slow thermohaline circulation. Ripple marks in sediments, scour lines, and the erosion of rocky outcrops on deep-ocean floors are evidence that relatively strong, localized bottom currents exist. Some of these currents may move as rapidly as 60 centimeters (24 inches) per second.

These currents are strongly influenced by bottom topography, since dense, bottom water must forcefully flow around seafloor projections. Thus, they are sometimes called contour currents. Bottom currents generally move equator-ward at or near the western boundaries of ocean basins (below the western boundary surface currents). The deep-water masses are not capable of moving water at speeds comparable to that of wind-driven surface currents. Water in some of these currents may move only 1 to 2 meters per day. Even at that slow speed, the Coriolis effect modifies their pattern of flow.

Downwelling of deep water in polar regions

Antarctic Bottom Water is the most distinctive of the deep-water masses. It is characterized by a salinity of 34.65‰, a temperature of -0.5°C (30°F), and a density of 1.0279 grams per cubic centimeter. This water is noted for its extreme density (the densest in the world ocean), for the great amount of it produced near Antarctic coasts, and for its ability to migrate north along the seafloor. Most Antarctic Bottom Water forms near the Antarctic coast south of South America during winter. Salt is concentrated in pockets between crystals of pure water and then squeezed out of the freezing mass to form a frigid brine. Between 20 million and 50 million cubic meters of this brine form every second. The water’s great density causes it to sink toward the continental shelf, where it mixes with nearly equal parts of water from the southern Antarctic Circumpolar Current. The mixture settles along the edge of Antarctica’s continental shelf, descends along the slope, and spreads along the deep-sea bed, creeping north in slow sheets. Antarctic Bottom Water flows many times as slowly as the water in surface currents: in the Pacific it may take a thousand years to reach the equator. Antarctic Bottom Water also flows into the Atlantic Ocean basin, where it flows north at a faster rate than in the Pacific. Antarctic Bottom Water has been identified as high as 40º N on the Atlantic floor.

A small amount of dense bottom water also forms in the northern polar ocean. Although, the topography of the Arctic Ocean basin prevents most of the bottom water from escaping, with the exception of deep channels formed in the submarine ridges between Scotland, Iceland, and Greenland. These channels allow the cold, dense water formed in the Arctic to flow into the North Atlantic to form North Atlantic Deep Water. North Atlantic Deep Water forms when the relatively warm and salty North Atlantic Ocean cools as cold winds from northern Canada sweep over it. Exposed to the chilled air, water at the latitude of Iceland releases heat, cools from 10°C to 2°C, and sinks. Gulf Stream water that sinks in the north is replaced by warm water flowing clockwise along the U.S. east coast in the North Atlantic gyre.

Importance

A 1943 map of the world’s ocean currents.

Knowledge of surface ocean currents is essential in reducing costs of shipping, since traveling with them reduces fuel costs. In the sail-ship era knowledge was even more essential. A good example of this is the Agulhas Current, which long prevented Portuguese sailors from reaching India. Even today, the round-the-world sailing competitors employ surface currents to their benefit. Ocean currents are also very important in the dispersal of many life forms. An example is the life-cycle of the European Eel.

Ocean currents are important in the study of marine debris, and vice versa. These currents also affect temperatures throughout the world. For example, the current that brings warm water up the north Atlantic to northwest Europe stops ice from forming by the shores, which would block ships from entering and exiting ports, the currents have a decisive role in influencing the climate of the regions they flow through. The cold currents that flow from the polar and sub-polar regions, bring in a lot of plankton. Since this is the food of the fish you can find a lot of fish where these currents pass through.

OSCAR: Near-realtime global ocean surface current data set

The ‘OSCAR near-realtime global ocean circulation data set’ is based on NOAA and NASA satellite data (sea level altimetry, surface vector winds, and SST). The data set extends from 1993–present and is available at 1-degree and 1/3-degree resolution. The OSCAR data are continuously updated on an interactive website from which users can create customized graphics and download the data. A section of the website provides validation studies in the form of graphics comparing OSCAR data with moored buoys and global drifters.

OSCAR data are used extensively in climate studies. Monthly maps and anomalies have been published in the monthly Climate Diagnostic Bulletin since 2001, and are used routinely to monitor ENSO and to test prediction models. OSCAR currents are routinely used to evaluate the surface currents in Global Circulation Models (GCMs), for example in NCEP Global Ocean Data Assimilation System (GODAS) and European Centre for Medium-Range Weather Forecasts (ECMWF).^[3]

See also

Underwater diving portal

• Deep ocean water
• Thermohaline circulation
• Fish migration
• List of ocean circulation models
• Oceanic gyres
• Physical oceanography
• Marine current power
• Latitude of the Gulf Stream and the Gulf Stream north wall index

References

1. Essentials of Geology, 3rd ed., Stephen Marshak
2. “noaa ocean current service education”. Retrieved 12/5/2013.
3. OSCAR website

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