How an Aussie invention could soon cut 5% of the world’s greenhouse gas emissions



Australian-designed technology will soon be responsible for 50% of all solar energy produced globally.
Glenn Hunt/AAP

Andrew Blakers, Australian National University

In the 1980s, a global race was underway: to find a more efficient way of converting energy from the sun into electricity.

Some 30 years ago, our research team at the University of New South Wales (UNSW) came up with a breakthrough, called the PERC silicon solar cell. The cells have become the most widely deployed electricity generation technology in terms of capacity added globally each year – comfortably exceeding wind, coal, gas, hydro and others.




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PERC stands for Passivated Emitter and Rear Cell. By the end of this year, PERC technology will be mitigating about 1% of global greenhouse gas emissions by displacing coal burning. Assuming that its rapid growth continues, it should be reducing greenhouse gas emissions by 5% by the mid-2020s and possibly much more in later years.

The terrible bushfires in Australia this summer, enhanced by the hottest and driest year on record in 2019, underline the need for urgent reductions in greenhouse gas emissions. By far the most effective way is driving coal out of electricity systems through very rapid deployment of solar and wind.

Soon, our Aussie invention will be generating half the world’s solar power. It is a pertinent reminder of Australia’s capacity for finding transformative technical solutions to address climate change. But we need the right government support.

A solar farm near Canberra.
Lukas Coch/AAP

An Aussie invention

Solar cells convert sunlight directly into electricity without moving parts. More efficient solar cells generally produce cheaper electricity because fewer solar cells, glass covers, transport, land and support structures are needed for a given solar power output.

By the early 1980s, the best laboratory cells around the world had reached 17% efficiency. This means that 17% of the sunlight was converted to electricity, and the rest (83%) of the solar energy was lost (as heat).

During the 1980s, our research team at UNSW led by Martin Green and myself created a series of world-record-efficient silicon solar cells. We reported 18% efficiency in 1984, 19% efficiency also in 1984, and the important milestone of 20% efficiency in 1986.




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In 1989 our group reported a new solar cell design called “PERC”, with a record efficiency of 22-23%.

This new, more efficient cell was better than the old ones because we eliminated some defects in the silicon crystal surface, which led to lower electronic losses. The PERC design also enabled us to capture the sunlight more effectively.

In the 1990s, further improvements to laboratory PERC cells were made at UNSW, leading to cells in the 24-25% efficiency range. The global silicon solar cell efficiency record remained at UNSW until recently.

There was a 25-year gap between development of the PERC cell and its rapid commercial adoption, which began in 2013. During this time, many people worked to adapt the PERC design to commercial production.

PERC cells are more efficient than previous commercial cells. Strong incentives for more efficient cells have recently arisen due to the continually falling share of cell costs as a proportion of total solar power system costs (including transport, land and mounting systems).

The big benefits of solar

Currently, solar power constitutes more than 40% of net new electricity generation capacity additions, with fossil, nuclear, wind, hydro and other renewables making up the balance.

Solar is growing faster than the other electricity generation technologies. Over time, as fossil-fuelled power stations are retired, solar (and wind) will dominate electricity production, with consequent large reductions in greenhouse gas emissions.

Solar power has experienced sustained rapid exponential growth over decades, while other generation technologies are currently experiencing static, falling or negligible sales.
https://www.irena.org/publications/2019/Mar/Renewable-Capacity-Statistics-2019

This year, enough PERC solar modules will be sold to generate 60-70 gigawatts of power. According to projections, PERC will reach three quarters of annual solar module sales in the mid-2020s, enough to match the generation capacity additions from all other technologies combined.

About A$50 billion worth of PERC modules have been sold to date. This is expected to reach several hundred billion Australian dollars later this decade.

Just imagine

Australian emissions (excluding those from bushfires) are falling because we are installing solar and wind four times faster per capita than the EU, US, Japan and China.

Our position as a global leader in renewables installation is uncertain because the Renewable Energy Target, which was achieved in 2019, has not been extended.




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With supportive policy, such as facilitating more transmission to bring solar and wind power to the cities, Australia could greatly increase the speed at which wind and solar are deployed, yielding rapid and deep cuts at about zero-net cost.

Such policy would entail stronger and sustained government support for renewables deployment, and research and development of new technologies.

Renewables must replace polluting coal-fired power if the world is to tackle climate change.
SASCHA STEINBACH/EPA

Looking ahead

Solar energy is vast, ubiquitous and indefinitely sustainable. Simple calculations show that less than 1% of the world’s land area would be required to provide all of the world’s energy from solar power – much of it on building roofs, in deserts and floating on water bodies.

Solar systems use only very common materials (we could never run out), have minimal need for mining (about 1% of that needed for equivalent fossil or nuclear fuels), have minimal security and military risks (we will never go to war over solar access), cannot have significant accidents (unlike nuclear), and have minimal environmental impact over unlimited time scales.

Australia is making major contributions to mitigating climate change both through rapid deployment of wind and solar and technology development such as our PERC cells. But with better government support, much more can be done – quickly and at low cost.The Conversation

Andrew Blakers, Professor of Engineering, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate explained: which countries are likely to meet their Paris Agreement targets



To keep temperatures from rising above 1.5℃ requires reducing fossil fuel burning by half by 2032.
from http://www.shutterstock.com

Robert McLachlan, Massey University


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

Which countries in the world have met or bettered their Paris Agreement targets?

The 2015 Paris Agreement is much more than a one-off climate change deal. Its main aim to limit global warming to well below 2℃, ideally 1.5℃, was a breakthrough.

A follow-up report shows that keeping warming below 1.5℃ will require reducing fossil fuel burning by half by 2032. The 1.5℃ target has been written into New Zealand’s Zero Carbon Act.

But the ongoing process is also notable. Each country has registered a pledge (Nationally Determined Contribution, or NDC) to indicate how it plans to meet the agreement’s terms.

Without climate action, we are heading for 4.5℃ of warming by 2100. Current pledges, if fully realised, take us to 2.8℃.




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Countries have complete freedom regarding their target and how to achieve it. The NDCs will be revised every five years, first in 2020, and are required to be increasingly ambitious over time. The idea is that the international community can check the targets against performance and global goals. Best practice can be shared, and poor performance exposed.

This flexibility made it possible to get the agreement through, but it can be confusing. Targets have been set for different dates, from different baselines and for different types of emissions.

Countries may have good reasons for setting weaker targets – they may be starting from a low base, like India. Or they may have unusual emissions, like New Zealand’s large proportion of agricultural methane.




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So for each country we can ask:

  1. Does the target really reflect its highest level of ambition, as agreed in Paris?
  2. Is it consistent with 2℃ or 1.5℃ of global warming?
  3. Is it on track to meet its target?
  4. Will it ratchet up its ambition in 2020?

Let’s look at two large emitters, the EU and US, together responsible for 47% of historic, and 24% of current, emissions.

EU 2030 target: 40% reduction from 1990 levels

The European Union is on track for a 48% reduction, partly due to a collapse of heavy industry in Eastern Europe in the 1990s and more recently from a phase-out of coal. Despite this, because of lack of action on transport and buildings, and an increasing reliance on natural gas, the EU has been rated insufficient by Climate Action Tracker, an independent research unit founded in 2009 and partly funded by the German Ministry for Environment.

Last week, the new president of the European Commission, Ursula von der Leyen, announced plans for the EU to increase the target up to a 55% reduction, along with sweeping implementation plans. Some European countries are moving faster: Denmark, already down 32% on 1990 levels, has this month legislated a 70% reduction by 2030.

US 2025 target: 26% reduction from 2005 levels

So far the US is down 11%. The Obama-era climate plan would have achieved the 2025 target, but is now being rolled back, and the US will leave the Paris Agreement on November 4 next year, the day after the elections.

On the other hand, city and state-level actions and the continued decline of coal mean some further reductions in emissions are likely.

Now let’s consider two rapidly growing emitters, China and India, responsible for 16% of historic and 33% of current emissions.

China target: peak emissions by 2030

China is well on track to achieve this. Emissions actually levelled off for five years before rising again in 2018. China is the world’s largest installer of renewable energy, but also the world’s largest consumer of coal. It also funds a lot of coal power stations in other countries. China has announced it will greatly strengthen its target next year.

India’s 2030 target: reduce emissions intensity relative to GDP to 33% below 2005 levels

India is well on track to meet this, having rapidly moved into solar energy. Its target involves an increase in total emissions, but should be seen in light of India’s very low emissions of only two tonnes of carbon dioxide per capita. This is compatible with the 2℃ target.

Australia 2030 target: 26% below 2005 levels

Australia is presently only on track for a 7% reduction. But a decrease in forest clearance has masked the fact that emissions from fossil fuel burning have increased and are projected to increase further, to 8% above 2005 levels by 2030.

Australia has become the world’s third-largest exporter of fossil fuels, behind Russia and Saudi Arabia. On the other hand, many state governments have set ambitious targets and made either aspirational or legal commitments toward zero emissions.

New Zealand 2030 target: 30% below 2005 levels

New Zealand is projected to reduce by 15% under current policies, with the difference to be made up by purchasing carbon units from overseas. This may set up a clash with the Zero Carbon Act, which requires that “emissions budgets must be met, as far as possible, through domestic emissions reductions and domestic removals.” However, these figures mask the fact New Zealand is, most unusually, using “gross-net” accounting. The 2030 target is for net emissions (that is, including the carbon sink of forests), but is measured against their 2005 gross emissions. The target allows net emissions to grow by up to 24% and is woefully unambitious.

Using a different methodology, taking into account each country’s situation, performance, and plans, the Climate Change Performance Index found that the top three countries are Sweden, Denmark and Morocco, and the bottom three are Taiwan, Saudi Arabia and the US. New Zealand is ranked 34th and Australia 53rd of the 58 countries assessed.The Conversation

Robert McLachlan, Professor in Applied Mathematics, Massey University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Global emissions to hit 36.8 billion tonnes, beating last year’s record high


Pep Canadell, CSIRO; Corinne Le Quéré, University of East Anglia; Glen Peters, Center for International Climate and Environment Research – Oslo; Pierre Friedlingstein, University of Exeter; Robbie Andrew, Center for International Climate and Environment Research – Oslo; Rob Jackson, Stanford University, and Vanessa Haverd, CSIRO

Global emissions for 2019 are predicted to hit 36.8 billion tonnes of carbon dioxide (CO₂), setting yet another all-time record. This disturbing result means emissions have grown by 62% since international climate negotiations began in 1990 to address the problem.

The figures are contained in the Global Carbon Project, which today released its 14th Global Carbon Budget.




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Digging into the numbers, however, reveals a silver lining. While overall carbon emissions continue to rise, the rate of growth is about two-thirds lower than in the previous two years.

Driving this slower growth is an extraordinary decline in coal emissions, particularly in the United States and Europe, and growth in renewable energy globally.

A less positive component of this emissions slowdown, however, is that a lower global economic growth has contributed to it. Most concerning yet is the very robust and stable upward trends in emissions from oil and natural gas.

Coal is king, but losing steam

The burning of coal continues to dominate CO₂ emissions and was responsible for 40% of all fossil fuel emissions in 2018, followed by oil (34%) and natural gas (20%). However, coal emissions reached their highest levels in 2012 and have remained slightly lower since then. Emissions have been declining at an annual average of 0.5% over the past five years to 2018.

Coal emissions hit a peak in 2012 and have been declining ever since.
Global Carbon Project 2019

In 2019, we project a further decline in global coal CO₂ emissions of around 0.9%. This decline is due to large falls of 10% in both the US and the European Union, and weak growth in China (0.8%) and India (2%).

The US has announced the closure of more than 500 coal-fired power plants over the past decade, while the UK’s electricity sector has gone from 40% coal-based power in 2012 to 5% in 2018.

Whether coal emissions reached a true peak in 2012 or will creep back up will depend largely on the trajectory of coal use in China and India. Despite this uncertainty, the strong upward trend from the past has been broken and is unlikely to return.

Oil and natural gas grow unabated

CO₂ emissions from oil and natural gas in particular have grown robustly for decades and show no signs of slowing down. In fact, while emissions growth from oil has been fairly steady over the past decade at 1.4% a year, emissions from natural gas have grown almost twice as fast at 2.4% a year, and are estimated to further accelerate to 2.6% in 2019. Natural gas is the single largest contributor to this year’s increase in global CO₂ emissions.

This uptick in natural gas consumption is driven by a range of factors. New, “unconventional” methods of extracting natural gas in the US have increased production. This boom is in part replacing coal for electricity generation.




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In Japan, natural gas is filling the void left by nuclear power after the Fukushima disaster. In most of the rest of the world, new natural gas capacity is primarily filling new energy demand.

Oil emissions, on the other hand, are largely being driven by the rapidly growing transport sector. This is increasing across land, sea and air, but is dominated by road transport.

Australia’s emissions have also seen significant reductions from coal sources over the past decade, while emissions from oil and natural gas have grown rapidly and are driving the country’s overall growth in fossil CO₂ emissions.

CO₂ emissions from fossil fuels in Australia (in million tonnes).
Data Source: UNFCCC, CDIAC, BP, USGS

Emissions from deforestation

Preliminary estimates for 2019 show that global emissions from deforestation, fires and other land-use changes reached 6 billion tonnes of CO₂ – about 0.8 billion tonnes above 2018 levels. The additional emissions largely come from elevated fire and deforestation activity in the Amazon and Southeast Asia.

The accelerated loss of forests in 2019 not only leads to higher emissions, but reduces the capacity of vegetation to act as a “sink” removing CO₂ from the atmosphere. This is deeply concerning, as the world’s oceans and plants absorb about half of all CO₂ emissions from human activities. They are one of our most effective buffers against even higher CO₂ concentrations in the atmosphere, and must be safeguarded.

Fires and deforestation in the Amazon and Southeast Asia drove a new record high in land-related emissions.
Global Carbon Project 2019

Not all sinks can be managed by people – the open ocean sink being an example – but land-based sinks can be actively protected by preventing deforestation and degradation, and further enhanced by ecosystem restoration and reforestation.




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For every year in which global emissions grow, the goals of the Paris Agreement are one step further removed from being achievable. We know many ways to decarbonise economies that are good for people and the environment. Some countries are showing it is possible. It is time for the rest of the world to join them.The Conversation

Pep Canadell, Chief research scientist, CSIRO Oceans and Atmosphere; and Executive Director, Global Carbon Project, CSIRO; Corinne Le Quéré, Royal Society Research Professor, University of East Anglia, University of East Anglia; Glen Peters, Research Director, Center for International Climate and Environment Research – Oslo; Pierre Friedlingstein, Chair, Mathematical Modelling of Climate, University of Exeter; Robbie Andrew, Senior Researcher, Center for International Climate and Environment Research – Oslo; Rob Jackson, Chair, Department of Earth System Science, and Chair of the Global Carbon Project, globalcarbonproject.org, Stanford University, and Vanessa Haverd, Senior research scientist, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Making every building count in meeting Australia’s emission targets



While many Australian households have solar power, our very large houses and wasteful use of building space are factors in our very high emissions.
Jen Watson/Shutterstock

Timothy O’Leary, University of Melbourne

Buildings in Australia account for over 50% of electricity use and almost a quarter of our carbon emissions but the failures, frailties and fragmentation of the construction sector have created a major obstacle to long-term reductions. Reducing our carbon footprint plays second fiddle to the multibillion-dollar work of replacing flammable cladding, asbestos and other non-compliant materials and ensuring buildings are structurally sound and can be safely occupied.

Buildings – whether residential, commercial or institutional – do not score well under the nation’s main emissions reduction program, the A$3.5 billion Climate Solutions Package. This is intended to help meet Australia’s 2030 Paris Agreement commitment to cut emissions by 26–28% from 2005 levels.

This climate fund has very successfully generated offsets under the vegetation and waste methods – these projects account for 97% of Australian carbon credit units issued. But built environment abatements have been very disappointing.




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Australians have very high emissions per person. That’s partly due to how we use our buildings.

Our states and territories control building regulations. This year the Council of Australian Governments (COAG) set ambitious energy-reduction trajectories for buildings out to 2022 and beyond. This was to be achieved through amendments to national codes and implementing energy-efficiency programs.

Making the best use of our buildings

Last month, the Green Building Council and Property Council launched a policy toolkit, called Making Every Building Count. The councils urged governments to adopt practical plans to reduce emissions in the building sector.

The toolkit contains no fewer than 75 recommendations for all tiers of government. These are the result of work done through industry and university research partnerships in places like the Low Carbon Living Collaborative Research Centre – now disbanded after its seven-year funding ended.




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Most energy-efficiency studies and programs focus solely on the operational aspect of buildings, such as the energy used to heat and cool them. However, various studies have proved that the energy and emissions required to manufacture building products, even energy-saving products such as insulation, can be just as significant.

A more holistic approach is to look at the embodied energy already in our building stock, which then poses a serious question about our consumption. So, besides aspirational codes for net zero-energy buildings, we should be asking: can we meet our needs with fewer new buildings?




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In Melbourne, for example, an estimated 60,000 homes are sitting unused. Commercial property has very high vacancy rates – up to one in six premises are unoccupied in parts of the city. This points to a less-than-effective market in valuing our embodied carbon emissions in property.

If we are to get serious about reducing emissions, we need to tackle inefficient space use.

Empowering people to cut emissions

In occupied commercial buildings, some evidence suggests most building managers are grappling with complexity and challenging tenant behaviours. They also don’t get the clear information they need to continually improve their building’s performance beyond a selected benchmark.

In residential property, home energy performance is very much in our own hands. So we need to consider the means, motivations and opportunities of households, which I did in my doctoral study. A major barrier is that most of us don’t even know what we are getting when we buy or rent an ageing stock of more than 9 million homes.

Europe and the United States moved to mandatory residential energy disclosure at point of sale and lease well over a decade ago. If you rent or buy a home in these countries you get an energy performance certificate. It identifies emissions intensity and gives advice on how to operate the home more efficiently and hence with lower emissions.

In Australia, we have just sat on a commitment made by COAG back in 2009 to introduce a nationwide scheme.

Size matters, too. Residential space per person is high by international standards. Although McMansions are on the wane, our apartments are getting a bit bigger. The average size of freestanding houses built in 2018-19 shrank by 1.3% from 2017-18 to a 17-year low of 228.8 square metres.

And we are putting more solar on our roofs as a carbon offset. As of September 30 2019, Australia had more than 2.2 million solar photovoltaic (PV) installations. Their combined capacity was over 13.9 gigawatts.

However, the trend towards high-rise living is not helpful for emissions. Solar for strata apartments is tricky.

I recently worked with colleagues in Australia and overseas in a study of the user experience of PV. We found residents face a range of issues that limit emission reductions. These issues include:

  • initial sizing and commissioning with component failures such as faulty inverters
  • lack of knowledge about solar and expected generation performance
  • regulatory barriers that limit the opportunity to upgrade system size.

Looking to improve regulations and codes and billion-dollar funds may be sensible ways to meet emission targets, but human empowerment is the secret weapon in improving energy performance and lowering emissions. Good low-carbon citizens will help create good low-carbon cities.




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A set of clear guides on how to use a building is a good starting point. The low-carbon living knowledge hub provides these.

What will make every building count in lowering emissions is the behaviour of occupants, the commitment of owners to make their buildings low-carbon and building managers’ ability to become more adept at reducing building-related emissions.The Conversation

Timothy O’Leary, Lecturer in Construction and Property, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Green cement a step closer to being a game-changer for construction emissions



If the cement industry were a country, it would be the third-largest emitter of CO₂ in the world.
Joe Mabel/Wikimedia, CC BY-SA

Yixia (Sarah) Zhang, Western Sydney University; Khin Soe, Western Sydney University, and Yingying Guo, UNSW

Concrete is the most widely used man-made material, commonly used in buildings, roads, bridges and industrial plants. But producing the Portland cement needed to make concrete accounts for 5-8% of all global greenhouse emissions. There is a more environmentally friendly cement known as MOC (magnesium oxychloride cement), but its poor water resistance has limited its use – until now. We have developed a water-resistant MOC, a “green” cement that could go a long way to cutting the construction industry’s emissions and making it more sustainable.

Producing a tonne of conventional cement in Australia emits about 0.82 tonnes of carbon dioxide (CO₂). Because most of the CO₂ is released as a result of the chemical reaction that produces cement, emissions aren’t easily reduced. In contrast, MOC is a different form of cement that is carbon-neutral.

Global CO₂ emissions from rising cement production over the past century (with 95% confidence interval).
Source: Global CO2 emissions from cement production, Andrew R. (2018), CC BY



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What exactly is MOC?

MOC is produced by mixing two main ingredients, magnesium oxide (MgO) powder and a concentrated solution of magnesium chloride (MgCl₂). These are byproducts from magnesium mining.

Magnesium oxide (MgO) powder (left) and a solution of magnesium chloride (MgCl₂) are mixed to produce magnesium oxychloride cement (MOC).
Author provided

Many countries, including China and Australia, have plenty of magnesite resources, as well as seawater, from which both MgO and MgCl₂ could be obtained.

Furthermore, MgO can absorb CO₂ from the atmosphere. This makes MOC a truly green, carbon-neutral cement.




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MOC also has many superior material properties compared to conventional cement.

Compressive strength (capacity to resist compression) is the most important material property for cementitious construction materials such as cement. MOC has a much higher compressive strength than conventional cement and this impressive strength can be achieved very fast. The fast setting of MOC and early strength gain are very advantageous for construction.

Although MOC has plenty of merits, it has until now had poor water resistance. Prolonged contact with water or moisture severely degrades its strength. This critical weakness has restricted its use to indoor applications such as floor tiles, decoration panels, sound and thermal insulation boards.

How was water-resistance developed?

A team of researchers, led by Yixia (Sarah) Zhang, has been working to develop a water-resistant MOC since 2017 (when she was at UNSW Canberra).

Adding industrial byproducts fly ash (above) and silica fume (below) improves the water resistance of MOC.
Author provided

To improve water resistance, the team added industrial byproducts such as fly ash and silica fume to the MOC, as well as chemical additives.

Fly ash is a byproduct from the coal industry – there’s plenty of it in Australia. Adding fly ash significantly improved the water resistance of MOC. Flexural strength (capacity to resist bending) was fully retained after soaking in water for 28 days.

To further retain the compressive strength under water attack, the team added silica fume. Silica fume is a byproduct from producing silicon metal or ferrosilicon alloys. When fly ash and silica fume were combined with MOC paste (15% of each additive), full compressive strength was retained in water for 28 days.

Both the fly ash and silica fume have a similar effect of filling the pore structure in MOC, making the cement denser. The reactions with the MOC matrix form a gel-like phase, which contributes to water repellence. The extremely fine particles, large surface area and high reactive silica (SiO₂) content of silica fume make it an effective binding substance known as a pozzolan. This helps give the concrete high strength and durability.

Scanning electron microscope images of MOC showing the needle-like phases of the binding mechanism.
Author provided



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Although the MOC developed so far had excellent resistance to water at room temperature, it weakened fast when soaked in warm water. The team worked to overcome this by using inorganic and organic chemical additives. Adding phosphoric acid and soluble phosphates greatly improved warm water resistance.

Examples of building products made using MOC.
Author provided

Over three years, the team has made a breakthrough in developing MOC as a green cement. The strength of concrete is rated using megapascals (MPa). The MOC achieved a compressive strength of 110 MPa and flexural strength of 17 MPa. These values are a few times greater than those of conventional cement.

The MOC can fully retain these strengths after being soaked in water for 28 days at room temperatures. Even in hot water (60˚C), the MOC can retain up to 90% of its compressive and flexural strength after 28 days. The values remain as high as 100 MPa and 15 MPa respectively – still much greater than for conventional cement.

Will MOC replace conventional cement?

So could MOC replace conventional cement some day? It seems very promising. More research is needed to demonstrate the practicability of uses of this green and high-performance cement in, for example, concrete.

When concrete is the main structural component, steel reinforcement has to be used. Corrosion of steel in MOC is a critical issue and a big hurdle to jump. The research team has already started to work on this issue.

If this problem can be solved, MOC can be a game-changer for the construction industry.




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The problem with reinforced concrete


The Conversation


Yixia (Sarah) Zhang, Associate Professor of Engineering, Western Sydney University; Khin Soe, Research Associate, School of Computing, Engineering and Mathematics, Western Sydney University, and Yingying Guo, PhD Candidate, School of Engineering and Information Technology, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Our shameful legacy: just 15 years’ worth of emissions will raise sea level in 2300



Indonesian residents wade through flood water near the Ciliwung river in Jakarta in February 2018. Our emissions in the near future will lock in sea level rise over centuries.

Bill Hare, Potsdam Institute for Climate Impact Research

Greenhouse gas emissions released over the first 15 years of the Paris Agreement would alone lock in 20cm of sea-level rise in centuries to come, according to new research published today.

The paper shows that what the world pumps into the atmosphere today has grave long-term consequences. It underscores the need for governments to dramatically scale up their emission reduction ambition – including Australia, where climate action efforts have been paltry.

The report is the first to quantify the sea-level rise contribution of human-caused greenhouse gas emissions that countries would release if they met their current Paris pledges.

The 20cm sea-level rise is equal to that observed over the entire 20th century. It would comprise one-fifth of the 1m sea level rise projected for 2300.

A satellite image showing meltwater ponding in northwest Greenland near the ice sheet’s edge.
EPA/NASA EARTH OBSERVATORY

The picture is bleak

The study was led by researchers at Climate Analytics and the Potsdam Institute for Climate Impact Research, and was published today by the Proceedings of the National Academy of Sciences. It estimated the sea level rise to be locked in by 2300 due to greenhouse gas emissions between 2016 and 2030 – the first pledge period on the Paris treaty.

During those 15 years, emissions would cause sea levels to rise by 20cm by 2300. Even if the world cut all emissions to zero in 2030, sea levels would still rise in 2300. These estimates do not take into account the irreversible melting of parts of the Antarctic ice sheet.




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The researchers found that just over half of the sea level rise can be attributed to the top five polluters: China, the US, the European Union, India and Russia.

The emissions of these jurisdictions under will cause seas to rise by 12cm by 2300, the study shows.

The important takeaway message is that what the world does now will take years to play out – it is a stark warning of the long-term consequences of our actions.

Severe storms at Collaroy on Sydney’s northern beaches caused major damage to beachfront homes.
UNSW WATER RESEARCH

It’s worse than we thought

Last week a separate paper in Nature Communications showed sea-level rise could affect many more people than previously thought. The authors produced a new digital elevation model that showed many of the world’s coastlines are far lower than estimated with standard methods.

In low-lying parts of coastal Australia, for example, the previous data has
overestimated elevation by an average of 2.5m.

Their projections for the millions of people to be affected by sea-level rise are frightening. Within three decades, rising sea levels could push chronic floods higher than land currently home to 300 million people. By 2100, areas home to 200 million people could be permanently below the high tide line.

But what of Australia, girt by sea?

Australia is a coastal nation: the vast majority of our population lives within 50km of the sea, and will be heavily impacted by sea-level rise. Already, we’re seeing severe coastal erosion and inundation during king tides – and that’s without factoring in the impact of storm surges.

Clearly the world needs strong climate action to reduce greenhouse gas emissions as fast as possible. The Intergovernmental Panel on Climate Change has said emissions must be lowered to 45% below 2010 levels by 2030 and to zero by mid-century.

We also know that unless the world achieves this, we will not just lose parts of our coasts but also iconic ecosystems such as the Great Barrier Reef.



Australia’s emissions comprise a relatively small proportion of the global total – 1.4% or around 5% if we count coal and liquified natural gas exports. However, we have a much bigger diplomatic and political influence on the international stage.




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Australia’s hidden opportunity to cut carbon emissions, and make money in the process


Australia should use its position to push for urgent action internationally. But the federal government’s appalling record on emissions reduction – despite its efforts to claim otherwise – puts us in a very weak position on the global stage. We cannot point fingers at other nations while our emissions rise and we sell as much coal as possible to the rest of the world, while also burning as much as we can.



All the while, Australia is becoming the poster child for extreme sea-level events, more frequent and severe bushfires and other devastating climate impacts.

Governments, including Australia’s, must put forward much stronger 2030 emission reduction pledges by 2020. There should seek to decarbonise at a pace in line with the Paris Agreement’s 1.5°C temperature goal.

Otherwise, our emissions today will cause seas to rise far into the future. This process cannot be reversed – it will be our legacy to future generations.


Climate Analytics researcher Alexander Nauels was lead author of the study.The Conversation

Bill Hare, Director, Climate Analytics, Adjunct Professor, Murdoch University (Perth), Visiting scientist, Potsdam Institute for Climate Impact Research

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s hidden opportunity to cut carbon emissions, and make money in the process



A seagrass meadow. For the first time, researchers have counted the greenhouse gases stored by and emitted from such ecosystems.
NOAA/Heather Dine

Oscar Serrano, Edith Cowan University; Carlos Duarte, King Abdullah University of Science and Technology; Catherine Lovelock, The University of Queensland; Paul Lavery, Edith Cowan University, and Trisha B Atwood, Utah State University

It’s no secret that cutting down trees is a main driver of climate change. But a forgotten group of plants is critically important to fixing our climate — and they are being destroyed at an alarming rate.

Mangroves, tidal marshes and seagrasses along Australia’s coasts store huge amounts of greenhouse gases, known as blue carbon.

Our research, published in Nature Communications, shows that in Australia these ecosystems absorb 20 million tonnes of carbon dioxide each year. That’s about the same as 4 million cars.




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Worryingly, the research shows that between 2 million and 3 million tonnes of carbon dioxide is released each year by the same ecosystems, due to damage from human activity, severe weather and climate change.

This research represents the world’s most comprehensive audit of any nation’s blue carbon. Around 10% of such ecosystems are located in Australia — so preserving and restoring them could go a long way to meeting our Paris climate goals.

A pile of washed-up seaweed and beach erosion at Collaroy Beach on Sydney’s northern beaches. Storms can damage blue carbon ecosystems.
Megan Young/AAP

Super-charged carbon dioxide capture

Blue carbon ecosystems are vital in curbing greenhouse gas emissions. They account for 50% of carbon dioxide sequestered by oceans — despite covering just 0.2% of the world’s total ocean area — and absorb carbon dioxide up to 40 times faster than forests on land.

They do this by trapping particles from water and storing them in the soil. This means tidal marsh, mangrove and seagrass ecosystems bury organic carbon at an exceptionally high rate.

Globally, blue carbon ecosystems are being lost twice as fast as tropical rainforests despite covering a fraction of the area.

Since European settlement, about 25,000km² of tidal marsh and mangroves and 32,000km² of seagrass have been destroyed – up to half the original extent. Coastal development in Australia is causing further losses each year.

When these ecosystems are damaged — through storms, heatwaves, dredging or other human development — the carbon stored in biomass and soils can make its way back into the environment as carbon dioxide, contributing to climate change.

In Western Australia in the summer of 2010-11, about 1,000km² of seagrass meadows at Shark Bay were lost due to a marine heatwave. Similarly, two cyclones and several other impacts devastated a 400km stretch of mangroves in the Gulf of Carpentaria in recent years.

The beach and Cape Kimberley hinterland at the mouth of the Daintree River in Queensland.
Brian Cassey/AAP

Such losses likely increase carbon dioxide emissions from land-use change in Australia by 12–21% per year.

Aside from the emissions reduction benefits, conserving and restoring blue carbon ecosystems would also increase the resilience of coasts to rising sea level and storm surge associated with climate change, and preserve habitats and nurseries for marine life.

How we measured blue carbon – and why

The project was part of a collaboration with CSIRO and included 44 researchers from 33 research institutions around the world.

To accurately quantify Australia’s blue carbon stocks, we divided Australia into five different climate zones. Variations in temperature, rainfall, tides, sediments and nutrients mean plant productivity and biomass varies across regions. So ecosystems in a tropical climate such as North Queensland store carbon dioxide at a different rate to those in temperate climates such as southeastern Australia.




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We estimated carbon dioxide stored in the vegetation above ground and soils below for each climate area. We measured the size and distribution of vegetation and took soil core samples to create the most accurate measurements possible.

Blue carbon must be assessed on a national scale before policies to preserve them can be developed. These policies might involve replanting seagrass meadows, reintroducing tidal flow to restore mangroves or preventing potential losses caused by coastal development.

Seagrass at Queensland’s Gladstone Harbour.
James Cook University

There’s a dollar to be made

Based on a carbon price of A$14 per tonne – the most recent price under the federal government’s Emissions Reduction Fund – blue carbon projects could be worth tens of millions of dollars per year in carbon credits. Our comprehensive measurements provide greater certainty of expected returns for financiers looking at investing in such projects.

Restoring just 10% of blue carbon ecosystems lost in Australia since European settlement could generate more than US$11 million per year in carbon credits. Conserving such ecosystems under threat could be worth between US$22 million and US$31 million per year.




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Blue carbon projects cannot currently be counted towards Australia’s Paris targets, but federal environment authorities are developing a methodology for their inclusion. The reintroduction of tidal flow to restore mangrove and tidal marsh ecosystems has been identified as the most promising potential activity.

Other activities being explored include planning for sea level rise to allow mangrove and tidal marsh to migrate inland, and avoiding the clearing of seagrass and mangroves.

There are still questions to be answered about exactly how blue carbon can be used to mitigate climate change. But our research shows the massive potential in Australia, and allows other countries to use the work for their own blue carbon assessments.The Conversation

Oscar Serrano, ARC DECRA Fellow, Edith Cowan University; Carlos Duarte, Adjunct professor, King Abdullah University of Science and Technology; Catherine Lovelock, Professor of Biology, The University of Queensland; Paul Lavery, Professor of Marine Ecology, Edith Cowan University, and Trisha B Atwood, Assistant Professor of aquatic ecology, Utah State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.