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Published: 8 January 2013

Antarctic ice core project to reveal detail of past climate change


The federal government environment minister, Tony Burke, has announced a major new Australian-led project in Antarctica to advance the search for the scientific ‘holy grail’ of the million-year ice core, a frozen record of how our planet has evolved and changed and a guide to what might be in store.

An Antarctic ice core.
Credit: Joel Pedro

The Aurora Basin North project will drill a 400 metre deep ice core 600 kilometres inland from Casey station next summer to retrieve a 2000 year-long ice core from deep in the heart of east Antarctica.

This project will allow us to gain access to the most detailed record yet of past climate in this vast region.

Aurora Basin is the ideal site for the research as it has sufficient snowfall, 11 centimetres of ice per year, to provide the first record of year-to-year changes over the past 2000 years in this region of the continent.

Aurora Basin also harbours some of the deepest ice in Antarctica, over 3 km thick, and this project will provide new information that will guide the search for the oldest ice in Antarctica, thought to be over a million years old.

Mr Burke who this week visited Antarctica said the knowledge gained from doing science in Antarctica is critically important to understanding how the climate has naturally varied in the past and helping predict future responses to global climate change.

‘Ice cores provide the written history of our atmosphere and our water,’ Mr Burke said.

‘Seeking ice cores from this new area where there is much higher snow fall than other inland sites provides a massive increase in the level of detail which lives within the ice.

When it comes to the level of information we are able to obtain, shifting to this location should move us from a billboard to an encyclopaedia.

‘We have had information that is 2000 years old before, but we have never had access to this sort of detail which we believe lies deep within this part of the ice.

‘In my brief visit to the continent I had the privilege of seeing the vast Antarctic ice sheet first-hand. It is quite simply an unsurpassed scientific treasure chest of information ready to be unlocked.

‘The Aurora Basin project will draw on the data trapped in the ice sheet to fill a large gap in Antarctic climate records.

‘It will not only improve our understanding of regional and hemispheric climate links, but also help us when modelling changes to the global system into the future.

‘Australia is cooperating with other nations and contributing to this search. This involves groundwork like the Aurora Basin drilling, airborne surveys and computer modelling of the ice. It is expected that this will lead to actual drilling for a one million year old core by various international consortia in the coming years.

‘The Aurora Basin ice core data will go some way to address that by capturing aspects of climate variation with higher chronological precision than at any other inland Antarctic site.’

The international collaboration will involve about 20 scientists from Australia, Denmark, USA, and France.

A French team will traverse to the site in December next year, while the remaining scientists fly to the camp in January and February for the eight-week drilling project.

Source: AAD







Published: 17 January 2013

Crunch time for metals recycling?

Alex Serpo

With the world facing a rare-earth metals crisis, a paper published in the leading journal Science last year examined how far we are from cradle-to-cradle metal recycling, and identified future constraints and opportunities.

End-of-life recycling rates for commonly used metals such as iron, copper, zinc and lead are above 50 per cent. However, rare earths and other lesser known metals are seldom, if ever, recycled.
End-of-life recycling rates for commonly used metals such as iron, copper, zinc and lead are above 50 per cent. However, rare earths and other lesser known metals are seldom, if ever, recycled.
Credit: © rihardzz/istockphoto

In the paper, ‘Challenges in metal recycling’ written by US researcher, Barbara Reck, the author identifies a modern paradigm shift in metals use – today, humans exploit virtually every stable element in the periodic table.

In other words, we are now capitalising on every element’s unique physical and chemical properties, whereas for most of human history, we utilised only a handful of metals.

Another modern shift is that of recycling, a ubiquitous aspect of modern life. ‘The generation between 20 and 30 are now the first generation to have grown up with recycling bins as part of normal life,’ writes Reck from Yale University's Center for Industrial Ecology.

Reck adds, however, that the extent of modern metals recycling is well below potential.

'Metals are infinitely recyclable in principle. But in practice, recycling is often inefficient or essentially nonexistent because of limits imposed by social behaviour, product design, recycling technologies, and the thermodynamics of separation.'

She identifies two metrics that provide the most accurate measures of the rate of metals recycling – 'recycled content' and 'end-of-life recycling rate'.

Recycled content describes the share of scrap in metal production, which is important to get a sense of the magnitude of secondary supply. End-of-life recycling rate, on the other hand, is defined as the fraction of metal in discarded products that is reused in such a way as to retain its functional properties.

The paper makes reference to a United Nations’ panel that recently defined and quantified recycling rates for 60 elements. Two key trends are clear from this research.

The first is that end-of-life recycling rates for the commonly used base metals such as iron, copper, zinc and lead are above 50 per cent.

The second trend is that many trace elements are seldom, if ever, recycled. Most of these trace elements are increasingly used in small amounts for very precise technological purposes, such as red phosphors, high-strength magnets, thin-film solar cells, and computer chips.

In those applications, often involving highly comingled 'specialty metals', recovery can be so technologically and economically challenging that the attempt to recycle is seldom made.

'After millennia of products made almost entirely of a handful of metals, modern technology is today using almost every possible metal, but often only once. Few approaches could be more unsustainable,’ comments Reck.

Greater opportunities for collecting used metals have improved recycling rates over recent decades.
Greater opportunities for collecting used metals have improved recycling rates over recent decades.
Credit: Bidgee under CC-BY-SA-3.0 via Wikimedia Commons

In her paper, Recki identifies lead as a notable exception : '...80 per cent of today’s lead use is for batteries in automobiles and for backup power supplies, and collection and pre-processing rates from these uses are estimated to be within 90–95 per cent as a result of stringent regulation worldwide. The result is a nearly closed-loop system for lead use in batteries.'

While improved product design and enhanced deployment of modern recycling methodology will both improve recycling rates, Reck identifies one activity that stands out as the key to increasing recovery.

'It seems mundane at first telling, but the activity with the greatest potential to improve metal recycling is collection,' she writes. 'Much improvement is possible, but limitations of many kinds – not all of them technological – will preclude complete closure of the materials cycle.'

Reck also identifies a perverse incentive when it comes to product design for recycling: the more advanced and highly engineered the product, the more difficult it is to recycle. This is particularly true for electronics products, but also applies to other goods like cars, aeroplanes and whitegoods.

Collectively, today’s high-tech products make use of almost every metal, in contrast to earlier products that used only a handful of the more common metals.
Collectively, today’s high-tech products make use of almost every metal, in contrast to earlier products that used only a handful of the more common metals.
Credit: © Yutaka Tsutano under CC BY 2.0 licence via flickr

The paper identifies another paradox of modern materials recovery. 'It is not much of an exaggeration to say that we manufacture modern products with the best possible technologies we can devise, but generally recycle them with relatively basic approaches.

'It is unfortunate from a materials perspective that, for reasons of scale and economics, often only the more basic technologies (shredding, crushing, magnetic sorting) are routinely applied, whereas more advanced technologies (such as laser, near-infrared, or x-ray sorting) are limited to selected recyclate streams.'

The paper dismisses the common notions of infinite recyclability for bulk recycling of common metals.

'Markov chain modelling shows that a unit of the common metals iron, copper, or nickel is only reused two or three times before being lost, gainsaying the notion of metals being repeatedly recyclable.'

Reck’s concluding comments identify how materials substitution could help improve the sustainability of metals supplies.

'Sometimes, scarce metals can be replaced by more common metals with only modest loss of product performance. Examples are aluminum-doped zinc oxides substituting for indium tin oxides in liquid crystal.’

This is a lightly edited version of an article that first appeared in Business Environment Network (BEN) and is reproduced with permission.






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