News - UNSW - Science

Air pollution may be driving expansion of tropics

Thu, 17 May 2012 00:00:00 -1000

Black carbon aerosols and ozone, both man-made pollutants emitted predominantly in the Northern Hemisphere’s low- to mid-latitudes, are most likely pushing the boundary of the tropics further poleward in that hemisphere, new research by a team of scientists shows.

While depletion of the ozone layer high up in the stratosphere has already been shown to be the primary driver of the expansion of the tropics in the Southern Hemisphere, the researchers are the first to report that black carbon and ozone pollution nearer the Earth’s surface are probably doing likewise in the Northern Hemisphere.

The study results appear in the May 17 issue of the journal Nature. Climatologist Robert J. Allen, at the University of California, Riverside, led the team. It included Professor Steven Sherwood, co-director of the UNSW Climate Change Research Centre.

The observed tropical belt expansion by 0.7 degrees latitude per decade has been greater than climate models predicted, but this study considered newer estimates of regional trends in air pollution. When this data was included, the models more closely agreed with the observations.

The researchers note that an unabated tropical belt expansion would have an impact on large-scale atmospheric circulation, especially in the subtropics and mid-latitudes.

“Both black carbon and tropospheric ozone warm the tropics by absorbing solar radiation,” Allen says. “Because they are short-lived pollutants, with lifetimes of one to two weeks, their concentrations remain highest near the sources: the Northern Hemisphere low- to mid-latitudes. It’s the heating of the mid-latitudes that pushes the boundaries of the tropics poleward.

“If the tropics are moving poleward, then the subtropics will become even drier. If a poleward displacement of the mid-latitude storm tracks also occurs, this will shift mid-latitude precipitation poleward, impacting regional agriculture, economy, and society.”

Climate scientists have observed that the tropics have widened by 0.7 degrees latitude per decade in recent times, with warming from greenhouse gases also contributing to the expansion in both hemispheres.

“This has typically been blamed on global warming, although in the Southern Hemisphere some studies have suggested the ozone hole may be playing a lead role,” says Sherwood.

“We have confirmed the finding that ozone loss has been the main driver in the Southern Hemisphere, but also that air pollution trends - mainly increases in China and to some extent India - appear to have been the dominant counterpart driver in the Northern Hemisphere. Both are beating out global warming driven by greenhouse gas increases.

“The ability of air pollutants to cause such an expansion derives from the geographic pattern of the changes, with increased emissions from Asia and decreased emissions from Europe, rather than any trend in the worldwide amount of pollution.”

Media contacts:

UCR - Iqbal Pittalwala (951) 827-6050, (951) 827-6397 iqbal@ucr.edu

UNSW – Steve Sherwood s.sherwood@unsw.edu.au

UNSW media liaison Bob Beale (+61) 411 705 435 bbeale@unsw.edu.au

Triple whammy: ocean warming, La Niña, and cyclone produced Queensland floods

Wed, 16 May 2012 00:00:00 -1000

A record La Niña event coupled with tropical cyclone Tasha generated most of the record deluge of rain that devastated much of Queensland in December 2010, but a new study has found that another big culprit was also in play - record high sea-surface temperatures off northern Australia.

It was thought that the twin impacts of the La Niña and the cyclone alone could explain why Queensland’s December rainfall was an all-time high at 154% above normal.

But the new calculations by climate researchers have revealed that evaporation from the warmer seas to the north and north-west of Australia probably contributed about a quarter of the total.

Sea-surface temperatures off northern Australia in the Indian Ocean, Arafura Sea and Coral Sea were unusually warm at the time, in places as much as 2 degrees C, the study notes: analysing 30 years of historic measurements, the study identified a general warming trend there of at least 0.2 degrees C per decade.

“If the observed warming trend in the sea-surface temperatures continues, this result suggests that future La Niña events are more likely to produce extreme precipitation and flooding than is present in the historical record,” says Dr Jason Evans, of the UNSW Climate Change Research Centre. Dr Evans led the study, to be published in the journal Geophysical Research Letters, with a French co-author, Dr Irène Boyer-Souchet.

“If the sea-surface temperature increases can be attributed to global warming, then the probability of La Niña events producing extreme precipitation responses similar to December 2010 will increase in the future.”

The researchers caution, however, that this was the strongest La Niña event during the satellite record and that equally extreme events may have occurred before the satellite record began.

The extreme December rains – coming after a wet spring - produced nine floods that affected almost 1,300,000 square kilometres of land, caused billions of dollars in damage, led to the evacuation of thousands of people, and resulted in 35 deaths.

La Niña conditions in the Pacific Ocean are well known to enhance Queensland’s rainfall. The heaviest falls occurred between December 23 and 28, 2010, when a moist easterly airflow covered most of Queensland and Cyclone Tasha made landfall south of Cairns. Large parts of eastern Queensland received more than 100 mm of rain and several stations set all-time daily records, with some receiving around 300 mm in one day.

Modelling reconstructions showed that on December 14, a low-pressure centre formed off the north-west coast of Australia and moisture-laden air was carried east to New Guinea then south into Queensland, contributing directly to heavy rain between December 23 and 26.

Media contacts:
Jason Evans – 02 9385 7066 jason.evans@unsw.edu.au
UNSW Faculty of Science media liaison - Bob Beale 0411 705 435 bbeale@unsw.edu.au

Secret soil cracks linger underground

Tue, 15 May 2012 00:00:00 -1000

Deep cracks in soil that appear during long dry spells can remain open underground even after they have visibly sealed on the surface, a new study has found.

The results could have important implications for agricultural management around the timing and intensity of water and pesticide applications.

“These soils are very fertile and provide the most productive agricultural land in Australia,” said lead author Dr Anna-Katrin Greve, a postdoctoral fellow with UNSW’s Connected Waters Initiative.

“Lower water application intensity will give soil cracks time to close and more frequent irrigations could prevent the soil cracks from reforming.”

These cracks, which form during extended dry periods, provide “preferential pathways” allowing water to flow much faster than it would through non-cracked soil.

This means nutrients and pesticides are rapidly transported beyond the crops’ root-zone, said Greve, and if the plants can't access the water it has effectively been wasted.

By sending an electrical current through the ground at different angles, the UNSW researchers can measure directional differences in current conduction, which offers clues about how water is moving through the soil.

This innovative technique means they can, for the first time, detect the exact time when preferential sub-surface pathways close. This is important for irrigators, as water flow through non-cracked soil is far more predictable.

Their findings, which have been accepted for publication in the journal Geoderma, reveal that surface appearances can be deceiving.

“We showed that soil cracks that developed in dry periods remain open as preferential flow paths, even after the cracks are visually closed,” said Greve.

Researchers measured the flow of electrical current through a soil profile that was set-up over several years. The soil was contained in a fiberglass barrel, which had a small drain at the base.

Two irrigation events were carried out approximately 14 days apart. Each event used water from different sources, meaning the two samples had different stable isotope signatures, allowing researchers to distinguish between them.

At the time of the first irrigation event there were visible cracks upwards of three centimetres wide in the soil. By the time of the second irrigation, these cracks had visibly closed.

Despite this surface closure, the water from the second irrigation actually drained faster. It bypassed the sections of the soil where water from the first event was presumably stored and drained with signs of limited mixing, researchers said, meaning preferential flow paths must have remained open.

Greve’s study was awarded best paper at a geoscience conference in Europe in 2011 and she recently presented her findings at a conference in Arizona.

Media Contacts:
Dr Anna-Katrin Greve | 02 8071 9879 | a.greve@wrl.unsw.edu.au
Myles Gough, UNSW Media Office | 0420 652 825 | myles.gough@unsw.edu.au

Veena Sahajwalla appointed to Climate Commission

Tue, 15 May 2012 00:00:00 -1000

Scientia Professor Veena Sahajwalla, of the UNSW School of Materials Science and Engineering, has been appointed as a commissioner on the Australian Government's Climate Commission.

Announcing the apppointment yesterday, the Minister for Climate Change and Energy Efficiency, Mr Greg Combet, said: "Professor Sahajwalla has conducted world-leading research in collaboration with major resources companies in Australia.

"Professor Sahajwalla’s understanding of Australian industries together with her expertise in science communication will be valuable additions to the Climate Commission.”

She is an award-winning scientist and engineer, whose achievements include inventing a process of recycling plastics and rubber tyres in steelmaking. The benefits of this technology for Australian steelmaking include reduced energy use, which means lower
greenhouse gas emissions.

She replaces Dr Susannah Eliott, who has stepped down from her role as a Climate Commissioner due to an increase in her other professional commitments with the Australian Science Media Centre.

Professor Sahajwalla is Associate Dean (Strategic Industry Relations) of the UNSW Faculty of Science and Director of the Centre for Sustainable Materials Research and Technology.

Professor Sahajwalla has substantial research and development expertise in the fields of energy efficiency, sustainable materials and recycling. She invented a process of recycling plastics and rubber tyres in steelmaking.

Professor Sahajwalla received the 2011 National Nokia Business Innovation Award at the Telstra Business Women's Awards. She has been a judge on the ABC TV program The New Inventors and was an invited speaker at TEDxSydney 2011.

She will become one of six members of the Climate Commission, which was established in early 2011 to provide information and expert advice to the government and the Australian public.

The independent Commission is led by Professor Tim Flannery, one of Australia's leading writers on climate change and an internationally recognised scientist and conservationist. The Commissioners have met with many business and industry leaders and with communities around the country through public forums.

Media contacts:
Minister's office - Mark Davis, Gia Hayne 02 6277 7920
UNSW Faculty of Science - Bob Beale 0411 705 435 bbeale@unsw.edu.au

COMMENT: Bisexual dolphins? No: just stay-at-homes

Mon, 14 May 2012 00:00:00 -1000

Media reports on recent research into social alliances among male dolphins took a strange and unexpected turn. Professor Rob Brooks* explains:

A few weeks ago a big story about dolphins beset the net. Not just dolphins; rather "bisexual dolphins", "gay dolphins" and "gang rapist dolphins". With just the right juxtaposition of sexual taboo and a charismatic animal, the story got the kind of global media coverage that whets a PR consultant's dreams.

But Richard Connor and his collaborators whose work the story described weren't cracking open the champagne. They had reported an uncontroversial (but important) finding that bottlenose dolphin societies are "open" -- lacking rigidly defined boundaries between group territories. They also found that both males and females were likely to settle as adults quite near to where they were born and raised.

At the time, I wrote a column (and my colleague Stephen Hamblin wrote a better blog post) about how this international breaking story wasn't really a story at all.

As Hamblin put it:

If the 'writers' of these articles had read the paper, they would have noticed that it contains nothing about the sexual behaviour of the dolphins they studied, bisexual or otherwise, aside from brief mentions of the possible consequences of social networks on reproductive success. It certainly didn't mention anything about bisexual behaviour, homosexual behaviour, or rape.

The whole circus arose from a misconstrual of a simple phrase in the paper: "bisexual philopatry."

As my UNSW colleague and one of the study's authors, Professor Bill Sherwin, told me at the time, "'bisexual philopatry' ... when translated out of jargon means "males stay near where they were born, AND females stay near where they were born" -- nothing more or less than that.

But the word 'bisexual' was too good to pass up. It reminded journalists of all the unconventional sexual shennaniganizing for which male dolphins have long earned infamy. Male dolphins have been known for over half a century to copulate with one another, as well as to self-stimulate against all manner of objects.

Richard Connor and other colleagues showed, almost 20 years ago that male dolphins work in alliances to cut a female off from the pod and coerce her into mating. It's a behaviour that forever associated male dolphins with the human idea of 'gang rape.'

Some news outlets focused mainly on this disturbing aspect of dolphin behaviour. Britain's Daily Telegraph, for example, led with the punchy headline "Dolphins 'resort to rape.'"

Others ran headlines inspired by the presence of the word "bisexuality":

• News.com.au: "Male dolphins are bisexual, U.S. scientists claim."

• And according to India's ZEENEWS, "Male dolphins engage in extensive bisexuality."

In the Huffington Post, a short report on the story focused mainly on dolphin homosexuality and bisexuality, followed by a penguin-heavy slide show of other "gay" animals.

Browsing the comments from this and other reports at the time I was struck by the extent to which some readers extrapolated from dolphins to humans. 'If it's natural enough for dolphins,' went one of the more pro-diversity trains of thought, 'then it ought to be good enough for human beings.'

This kind of extrapolation has become rather common of late, including among scientists. The influential ecologist Joan Roughgardenwrote an entire book, Evolution's Rainbow, drawing attention to the diversity of sex roles and gender relations in the animal kingdom.

Roughgarden's perspective was, I can only imagine, shaped by her own transgendered experience. She, and many people in the LGBT community have had to put up with lifetimes of half-baked arguments about their own gender identity or sexuality being 'unnatural.'

But pointing to the diversity of behaviors in the animal world can only take a cause so far.

Certainly there are many animals, including our bonobo cousins, in which homosexual and bisexual intercourse runs perfectly natural riot. And these examples certainly demolish the simplistic claim that homosexuality and bisexuality are completely unnatural.

But one thing evolutionary biologists learn time and again is not to extrapolate narrowly from the way things are to the way they ought to be. The case for tolerance of diversity in sexuality, gender and other aspects of our lives should not depend on whether animals do similar things.

For example, it might be just as easy for homophobes to make an adaptive argument that their homophobia is every bit as natural as the homosexuality they so despise in others (and possibly in themselves).

The other side of the dolphin story illustrates my point. Dolphin bulls behave like gang rapists, harassing solitary females until, exhausted, the female copulates with one or all of the males.

Perhaps the similarities with the most repellent coalitional behavior among men are merely superficial. Perhaps they run deeper than that. That makes a fascinating question to be researched. Sensitively. But no matter what the findings, what dolphin males do in Shark Bay doesn't make that kind of behavior any more acceptable in men.

We can come to understand ourselves and our human motives by observing animals and by studying the evolution of our own species. But the fact that something happens in nature doesn't make it right.

Knowing that some dolphins, penguins and flamingos copulate with members of the same-sex can be a useful fact to turn back on those who decry homosexuality as a crime against nature.

But we also owe one another the dignity of recognizing same-sex human love, lust, jealousy and other emotions on their own, uniquely human terms.

*Rob Brooks is a professor in the UNSW School of Biological, Earth and Environmental Sciences and Director of the UNSW Evolution and Ecology Research Centre

Rob Brooks on Twitter: www.twitter.com/@Brooks_Rob

This article appeared originally in The Huffington Post.

You can’t play nano-billiards on a bumpy table

Mon, 14 May 2012 00:00:00 -1000

There’s nothing worse than a shonky pool table with an unseen groove or bump that sends your shot off course: a new study has found that the same goes at the nano-scale, where the “billiard balls” are tiny electrons moving across a “table” made of the semiconductor gallium arsenide.

These tiny billiard tables are of interest towards the development of future computing technologies. In a research paper titled “The Impact of Small-Angle Scattering on Ballistic Transport in Quantum Dots”, an international team of physicists has shown that in this game of “semiconductor billiards”, small bumps have an unexpectedly large effect on the paths that electrons follow.

Better still, the team has come up with a major redesign that allows these bumps to be ironed out. The study, led by researchers from the UNSW School of Physics, is published in the journal Physical Review Letters.

The team included colleagues, from the University of Oregon (US), Niels Bohr Institute (Denmark) and Cambridge University (UK).

“Scaled down a million-fold from the local bar variety, these microscopic pool tables are cooled to just above absolute zero to study fundamental science, for example, how classical chaos theory works in the quantum mechanical limit, as well as questions with useful application, such as how the wave-like nature of the electron affects how transistors work,” says team member Associate Professor Adam Micolich. “In doing this, impurities and defects in the semiconductor present a serious challenge.”

Ultra-clean materials are used to eliminate impurities causing backscattering (akin to leaving a glass on the billiard table) but until now has been no way to avoid the ionized silicon atoms that supply the electrons.

“Their electrostatic effect is more subtle, essentially warping the table’s surface.” explains Micolich.

Earlier studies assumed this warping was negligible, with the electron paths determined only by the billiard table’s shape (e.g. square, circular, stadium-shaped).

“We found that we can ‘reconfigure’ the warping by warming the table up and cooling it down again, with the electron paths changing radically in response,” says Professor Richard Taylor from the University of Oregon. “This shows that the warping is much more important than expected.”

Using a new billiard design developed during PhD work at UNSW by lead author Dr Andrew See, the silicon dopants are removed, eliminating the associated warping, and enabling the electron paths to stay the same each time they cool the device down for study.

“These undoped billiard devices pinpoint the silicon dopants as the cause of the warping. The level of improvement obtained by removing the silicon was unexpected, earlier work on much larger devices suggested that we wouldn’t see this level of improvement.

But at the nanoscale, the dopant atoms really do make a really big difference”, says Micolich, “Ultimately, our work provides important insight into how to make better nanoscale electronic devices, ones where the properties are both more predictable, and more consistent each time we use them.”

Media contacts:
Adam Micolich – 02 9385 6132, 0408 479 432 adam.micolich@gmail.com
Bob Beale (UNSW Faculty of Science media liaison) 0411 705 435 bbeale@unsw.edu.au

Funding: Australian Research Council; Office of Naval Research; US Air Force; National Science Foundation, Research Corporation, and the UK Engineering and Physical Sciences Research Council.

Herds of large marsupials in the treetops

Thu, 03 May 2012 00:00:00 -1000

Sheep-sized ancient relatives of modern-day wombats lived in Australia’s treetops 15 million years ago, according to new research led by Dr Karen Black from the University of New South Wales.

The 70 kg marsupials – known as Nimbadon - were strikingly similar to koalas, says Dr Black, winner of the Australian Academy of Science’s 2012 Dorothy Hill Award for female researchers in the Earth sciences. Dr Black will discuss her preliminary findings as part of her presentation today at the Academy’s annual Science at the Shine Dome event.

“Nimbadon was a highly capable, habitual climber and its specialised anatomy suggests it may have adopted a trunk-hugging method of climbing similar to the living koala,” says Dr Black, whose collaborators are Dr Aaron Camens (Flinders University) and Professor Mike Archer and Associate Professor Sue Hand (both of UNSW).

The team’s research is still incomplete and has not yet been published, but Dr Black says it is already clear that Nimbadon's climbing ability would have allowed it to access multiple layers of the rainforest canopy.

“This ability would have reduced the competition it faced for food resources with other herbivores, such as kangaroos, and also to escape predators, such as marsupial lions.

“It may have also opportunistically fed on rainforest fruits and so played a role as a large seed disperser in Australia's ancient forests.”

The team’s research focuses on a 15-million-year old fossil cave at Riversleigh, in north-western Queensland. The cave is packed with even older animal bones and has revealed almost the entire life cycle of the Nimbadon, from suckling young in the pouch still cutting their milk teeth to elderly adults.

“The Nimbadon fossil material is an incredibly rare and significant resource, not only because it is so exceptionally well-preserved, but because it represents individuals from a range of ages,” says Dr Black. “The Nimbadon material has allowed the first detailed study of skull development in a fossil marsupial as well as brain development and behaviour.”

Their study is also providing a time perspective on the nature and rate of environmental change affecting Australia's past ecosystems, which will help anticipate the impacts of future climate change on Australian biodiversity.

See: http://science.org.au/events/sats/sats2012/documents/SATS2012-program.pdf

Media contacts:
Academy of Science - Mona Akbari 0447 679 612 mona.akbari@science.org.au
UNSW Faculty of Science – Bob Beale 0411 705 435 bbeale@unsw.edu.au

Related stories:

Bigger and brainier: did dingoes kill thylacines?

Thu, 03 May 2012 00:00:00 -1000

Direct attacks by introduced dingoes may have led to the extinction on the Australian mainland of the iconic marsupial predator, the thylacine, a new study suggests.

A comparison of museum specimens has found that thylacines on mainland Australia were smaller than those that persisted into modern times in Tasmania, and significantly smaller than dingoes. The last known Tasmanian thylacine died in 1936.

Measurements of the head size and thickness of limb bones of the semi-fossilised remains of thylacines and dingoes from caves in Western Australia have revealed that, on average, dingoes were larger than thylacines.

“In particular, dingoes were almost twice as large as female thylacines, which were not much bigger than a fox,” says ecologist Dr Mike Letnic, an ARC Future Fellow in the UNSW School of Biological, Earth and Environmental Sciences, who led the study with colleagues at the University of Sydney. The findings are published in the journal PLoS One.

There has long been debate as to what caused the extinction of the thylacine from mainland Australia, Dr Letnic notes. Because Tasmanian thylacines were much larger than dingoes, direct confrontation between the two species was discarded as a hypothesis for the thylacine decline.

Another hypothesis is that competition between the two species may have been the cause: however, competition is not thought to be a strong driver of extinction. More recently, some authors have suggested that people caused the extinction of the thylacine through direct hunting or suppression of prey.

“We were aware of old reports that mainland thylacines were smaller than Tasmanian ones,” says Letnic. “Modern ecological studies show that larger predators frequently kill smaller predators, so we decided to test the hunch that dingoes were actually larger than thylacines and caused their extinction by killing them in direct confrontations.

“We also measured the brain size of both species and found that dingoes also had much bigger brains than thylacines, so they may have outwitted them, too.”

Dingoes appear to have had a dramatic impact on the ecology of Australia when they first arrived between 3,500-5,000 years ago, probably introduced by human seafarers, and likely also caused the extinction of the Tasmanian devil from mainland Australia (devils are still found in Tasmania, which does not have dingoes).

“However, recent studies suggest that dingoes now play an integral role in maintaining healthy balanced ecosystems by limiting the populations of herbivores and smaller predators, a role that was once filled by the thylacine,” says Dr Letnic.

Media contacts:
Mike Letnic – 02 9385 2079 m.letnic@unsw.edu.au
Faculty of Science media liaison - Bob Beale 0411 705 435 bbeale@unsw.edu.au

The research paper can be found here:
http://dx.plos.org/10.1371/journal.pone.0034877

OPINION: the mining boom Australia will miss - asteroids

Wed, 02 May 2012 00:00:00 -1000

OPINION: There will be a future mining boom, as heralded in recent media stories. But this mining will take place in a location even more hostile than the Australian Outback – space.

More specifically, the ore bodies that comprise the myriad asteroids we now know are whizzing by our planet with alarming frequency.

The publicity blitz was provoked by the formation of a new US-based company, named Planetary Resources.

The company is backed by film director James Cameron and a host of well-known billionaires who made their fortunes in the aerospace and internet industries.

Planetary Resources has a seemingly unlikely aim, yet one that has been obvious to space scientists for at least 20 years: to mine near-Earth asteroids, which are composed of a wide variety of useful minerals.

One thing perhaps not made clear in the media furore, is the point of this mining. It’s not to divert the asteroids and bring them down to the surface of our planet, but rather to make use of their valuable constituents for utilisation in space.

When humankind starts its move off the earth we’ll need to start manufacturing various products in space, including high-quality alloys and electronics. On the larger scale we’ll also need to construct large, permanently inhabited off-planet islands and it will be near-Earth asteroids from which we derive the needed raw materials.

The reason for this is not a shortage of minerals and other necessary supplies down here on Earth, but rather the expense of getting them into space.

To get a rocket off Earth’s surface and into orbit we need to accelerate it to a speed of over 7.5km per second (or 27,000km/h). That is expensive, although launch costs have dropped in recent years to about US$10,000 per kilogram.

A cubic metre of water may cost you a few dollars from your bathroom tap, but the same volume would cost US$10 million to put into orbit. In fact, the cost would be even higher than that, due to the weight of the container needed to hold the water.

To send payloads further away, escaping Earth’s gravity and going into independent orbit around the sun, requires more energy still (and therefore more money).

Space researchers quantify the needed energy, and therefore the rocket sizes required, in terms of the Delta-V (∆V): the overall change in velocity (or speed) needed to rendezvous with some celestial target.

Imagine you’ve sent a rocket on its way to the moon. To execute a soft landing on the lunar surface and then blast-off again, as in the Apollo Program, requires a Delta-V of at least 6km/s.

That’s a lot. Remember, it was not much more (7.5km/s) to get off Earth and into orbit in the first place. To get to (say) Mars, land on its surface and then launch again and return to Earth, would necessitate a far higher Delta-V.

On the other hand, we now know of asteroids that pass close by Earth with relative speeds (and therefore required Delta-V for rendezvous) of only 2km/s. This means they are the most accessible objects in space.

Don’t be fooled by the fact that they spend most of their time far away from us: in space it’s not distance that counts, but the necessary Delta-V.

The next cosmic objects on to which we will place astronaut footprints will undoubtedly be the asteroids. This has been foreshadowed in the rhetoric of NASA and indeed by President Obama himself.

Forget the Moon and forget Mars: the asteroids are our next stop.

It’s in this context that Planetary Resources' mining plans should be considered. The backers know these are to be the major targets of future manned missions. They also know the same asteroids are made of the metals, rock and other materials we will need to develop a permanent presence off our planetary home.

For instance, we know that water is present out there in abundance, and astronauts will need water for drinking, for growing food and for splitting into its constituent atoms to get oxygen to breathe.

Once upon a time Australia was well-placed to be involved in this future boom. In 1989 I began the first southern-hemisphere search for near-Earth asteroids. Indeed it was the first search outside the USA.

In 1996 the federal government cut all funding, despite protests from all around the globe, including from some prominent people such as the late Edward Teller, a Hungarian-American particle physicist.

NASA was so aghast at these funding cuts (because related NASA projects were dependent on our observing capabilities) that funding was delivered from NASA to the University of Arizona to the Australian National University to pay the two main observers on my project – Rob McNaught and Gordon Garradd – to keep searching.

But as the great New Zealand physicist Lord Ernest Rutherford once said, science is either physics or stamp collecting and merely spotting new objects is definitely the latter.

Because of this Australia lost its pre-eminent position in near-Earth asteroid research.

The view of the Australian government was clear. In response to another wave of letters from around the world in 2002, urging a resumption of scientific research on these objects, the then Science Minister, Peter McGauran, went on Channel 9’s 60 Minutes to describe searching for near-Earth asteroids as being “a fruitless, unnecessary, self-indulgent exercise”.

And now NASA’s funding to Australia for near-Earth asteroid research has stopped forever, while other nations forge ahead.

If science really is Australia’s future (as CSIRO says it is), the country doesn’t have a hope, at least in this field.

Instead, we’ll watch on as the rest of the world, including Planetary Resources, take the next step in space exploration.

*Dr Duncan Steel is a Visiting Researcher at the Australian Centre for Astrobiology at UNSW.

This article first appeared in The Conversation

OPINION: "I can change your mind": look elsewhere for experts

Fri, 27 Apr 2012 00:00:00 -1000

Last night the ABC premiered the fascinating documentary “I can change your mind about climate”, in which Nick Minchin, the recently retired Liberal senator, and Anna Rose, the co-founder of the Australian Youth Climate Coalition, attempted to change each other’s minds about the reality of human-induced climate change.

As you might imagine, Minchin is sceptical of any human impact on the climate. He demands a high standard of proof before embarking on any radical changes that might require government intervention. Rose, while acknowledging some uncertainties, is convinced that we have enough information to act, and we must do so urgently to avoid a global catastrophe.

Climate scientists – I’m talking about the 97% or so that agree that humans have a considerable influence on the climate – are very uneasy with the false balance that a program such as this engenders. From the moment a climate scientist steps onto the stage with a climate denier, the audience’s default assumption will be that there is a 50:50 contest going on. It is going to be difficult or impossible for the scientist to win the argument at the 97:3 level that characterises the debate amongst experts, let alone the 99.99:0.01 level as it exists, roughly, in the scientific literature.

Anna Rose was very aware of this issue and, as she writes in her book Madlands, thought long and hard before agreeing to participate in the documentary. But with the producers going to proceed with Rose or with someone else, she bravely stepped up to the plate.

The documentary performed an intriguing experiment by plucking Minchin and Rose out of their comfort zones and thrusting them together for a month of filming on the road. Each was able to choose seven experts, from anywhere in the world, to help argue their cases. Will Nick convince Anna? will Anna convince Nick? And how will the viewers react?

For me, the most surprising part of the documentary was Minchin’s choice of experts: they were all duds who would only influence the gullible or those blinded by ideology. Although, to be fair to Minchin, there aren’t any non-dud experts on his side to choose from.

For example, blogger David Evans from Perth showed Rose an aerial photo of a meteorological station near an airport, declaring that half of the world’s “official” thermometers were like this and that they were measuring warming from jet aircraft engines more than anything else.

Rose’s response was “surely you don’t think climate scientists are that stupid?”

And of course Rose is right. Climate scientists aren’t stupid – global warming is clearly measured when only the highest quality rural meteorological stations are used.

Minchin’s other “experts” included blogger Joanne Codling (akaJo Nova), who blew all credibility when she stated that CO₂ has an immeasurably small impact on temperature, and contrarian Professor Richard Lindzen who has spent over 20 years trying, and repeatedly failing, to find any errors in the theory of human-induced climate change.

Lindzen only appears briefly in the documentary, and you will have to read Rose’s book for the full story of their encounter.

A more interesting choice from Minchin was Danish author Bjorn Lomborg. Over the years he has gone from denying that global warming exists, to saying it exists but it is much better to spend money on combating malaria, to saying that it exists and it is a critical problem. His solution now is to spend $100 billion a year in research and development for a magic technological fix, while keeping on burning fossil fuels.

This is like saying “let’s jump out of this airplane without a parachute, and we will research and develop ways of landing safely on the way down”.

The problem with Lomborg’s solution is that with climate we are up against very fundamental issues of physics that can’t be magicked away. Once a CO₂ molecule has been put into the atmosphere by burning fossil fuels, it is not easy to get it back out again. And once the Arctic is ice-free in summer, $100 billion or even $100 trillion isn’t going to turn the sea water back into ice.

It is interesting that the one constant in Lomborg’s changing position over the years has been “let’s keep burning fossil fuels”.

By far the worst of Minchin’s champions was Marc Morano, who runs the notorious cess-pit of climate denial climatedepot.com. Morano is a master of the Gish Gallop, spewing out a rapid-fire string of arguments – sea level is dropping, polar bear populations are increasing, temperatures are going down – which are impossible to refute on the spot in a television debate. Morano’s arguments were all wrong of course, as has been nicely explained by Graham Readfearn, but by the time you have researched this and are ready to respond, the camera has moved on.

Rose simply refused to engage with Morano, which is the only appropriate course of action.

In all, five of Minchin’s seven experts appeared in the documentary, but only three of Rose’s. While this might sound unfair to Rose, I think that Minchin’s experts did more harm to his cause than good.

That said, I was concerned to read Minchin being quoted in The Sydney Morning Herald yesterday as saying that the documentary was a “terrific opportunity to convey to an ABC audience that there remains a significant debate”. If Minchin had any insight he would realise that the documentary simply exposes his gullibility.

*Michael Ashley is a Professor of Astrophysics in the UNSW School of Physics.

This article was originally published at The Conversation here