Tag Archives: carbon dioxide

Mangroves’ message from the grave

Mangroves help fight climate change but they’re at serious risk from its effects. That’s one of the findings from a study of a massive mangrove dieback that occurred in late 2015.

Local fishermen reported mangroves were dying along hundreds of kilometres along the Gulf of Carpentaria coastline, an area known for its barramundi fishing and high value commercial fisheries.

This caught the attention of Dr Damien Maher of Southern Cross University, who is interested in the chemistry of mangroves—how they store carbon in their soils, remove planet-warming nitrous oxides from the atmosphere, and neutralise ocean acidification by releasing alkaline chemicals into nearby waters.

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Fresh Science 2010

Each year we identify early-career scientists with a discovery and bring them to Melbourne for a communication boot camp. Here are some of their stories.

More at www.freshscience.org.au

Print your own lasers, lights and TV screens

Print your own lasers, lights and TV screens
Jacek Jasieniak sprinkling quantum dots. Credit: Jacek Jasieniak

Imagine printing your own room lighting, lasers, or solar cells from inks you buy at the local newsagent. Jacek Jasieniak and colleagues at CSIRO, the University of Melbourne and the University of Padua in Italy, have developed liquid inks based on quantum dots that can be used to print such devices and in the first demonstration of their technology have produced tiny lasers. Quantum dots are made of semiconductor material grown as nanometre-sized crystals, around a millionth of a millimetre in diameter. The laser colour they produce can be selectively tuned by varying their size.

Cling wrap captures CO2
Colin Scholes operates a test rig for his carbon capture membrane. Credit: CO2 CRC

Cling wrap captures CO2

High tech cling wraps that ‘sieve out’ carbon dioxide from waste gases can help save the world, says Melbourne University chemical engineer, Colin Scholes who developed the technology. The membranes can be fitted to existing chimneys where they capture CO2 for removal and storage. Not only are the new membranes efficient, they are also relatively cheap to produce. They are already being tested on brown coal power stations in Victoria’s La Trobe Valley, Colin says. “We are hoping these membranes will cut emissions from power stations by up to 90 per cent.”

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Cementing a greener future

Making cement is the third largest source of carbon emissions in the world after the burning of fossil fuels and deforestation—but the Australian roads of the future could be paved with cement that is made in a process that generates less than half the carbon emissions of traditional methods.

Green cement is now becoming part of Victoria’s roads. Credit: Australian Synchrotron.
Green cement is now becoming part of Victoria’s roads. Credit: Australian Synchrotron.

Each year, the world produces about 12 billion tonnes of concrete and about 1.6 billion tonnes of its key ingredient, Portland cement, which is generated by breaking calcium carbonate into carbon dioxide and calcium oxide.

This produces some 2 billion tons of carbon dioxide—so the Geopolymer and Mineral Processing Group (GMPG) at the University of Melbourne, now led by Dr John Provis, went looking for a lower carbon way of making cement.

They have now developed binders and concretes based on a low-CO2 aluminosilicate compounds called geopolymers.

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Mopping up gases

Deanna D’Alessandro

University of Sydney

A sponge that filters hot air and captures carbon dioxide

Deanna D’Alessandro, The University of Sydney (credit: L’Oréal Australia/sdpmedia.com.au)
Deanna D’Alessandro, The University of Sydney (credit: L’Oréal Australia/sdpmedia.com.au)

We need better ways of capturing carbon dioxide emissions from power stations and industry. And we won’t be using hydrogen cars until we’ve developed practical ways of carrying enough hydrogen gas in the fuel tank. Deanna D’Alessandro’s understanding of basic chemistry has led her to create new, incredibly absorbent chemicals that could do both these jobs and much more.

It’s all to do with surface area. Working in California and in Sydney she has constructed crystals that are full of minute holes. One teaspoon of the most effective of her chemicals has the surface area of a rugby field. What’s more, the size and shape of the pores can be customised using light. So she believes she can create molecular sponges that will mop up carbon dioxide, hydrogen, or in theory almost any gas – and then release it on cue. Continue reading Mopping up gases

Ocean acidification threatens marine ecosystems

Ocean acidification, caused by increasing amounts of atmospheric carbon dioxide dissolving in the ocean, poses a serious threat to marine ecosystems.

Increasing acidity affects the ability of some planktonic organisms to form shells, and is expected to change the species composition of plankton, with flow-on effects to higher levels of the food web.

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Managing tropical fires for greenhouse gas abatement

Tiwi Ranger Leon Puruntatameri lighting experimental fires as part of the Tiwi Carbon Study. Credit: CSIRO Darwin
Tiwi Ranger Leon Puruntatameri lighting experimental fires as part of the Tiwi Carbon Study. Credit: CSIRO Darwin

The economic potential of carbon is the focus of a new fire project on the Tiwi Islands, 80 kilometres north of Darwin in the Northern Territory and home to 2,000 Aboriginal Australians. Nearly half of the Tiwi Islands are burnt every year, resulting in significant greenhouse gas emissions. Reducing the extent of fire may provide substantial financial benefits under the emerging carbon economy.

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Are forests really the carbon sink we need?

Ivett_300x180Evidence is building to suggest that our forests may not be the climate change ‘get out jail free’ card we all want.

Australian Rivers Institute’s Assoc. Prof. Peter Pollard has researched rainforest lakes and rivers to test a provocative theory. The respiration of bacteria living and ‘breathing’ in these freshwater ecosystems is a major pathway for the return of rainforest carbon back to the atmosphere as the greenhouse gas carbon dioxide.

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