What’s the net cost of using renewables to hit Australia’s climate target? Nothing

 Managed in the right way, wind farms can actually 
help stabilise the grid, rather than disrupting it. AAP Image/Lukas Coch

Australia can meet its 2030 greenhouse emissions target at zero net cost, according to our analysis of a range of options for the National Electricity Market.

Our modelling shows that renewable energy can help hit Australia’s emissions reduction target of 26-28% below 2005 levels by 2030 effectively for free. This is because the cost of electricity from new-build wind and solar will be cheaper than replacing old fossil fuel generators with new ones.


Read moreWant energy storage? Here are 22,000 sites for pumped hydro across Australia


Currently, Australia is installing about 3 gigawatts (GW) per year of wind and solar photovoltaics (PV). This is fast enough to exceed 50% renewables in the electricity grid by 2030. It’s also fast enough to meet Australia’s entire carbon reduction target, as agreed at the 2015 Paris climate summit.

Encouragingly, the rapidly declining cost of wind and solar PV electricity means that the net cost of meeting the Paris target is roughly zero. This is because electricity from new-build wind and PV will be cheaper than from new-build coal generators; cheaper than existing gas generators; and indeed cheaper than the average wholesale price in the entire National Electricity Market, which is currently A$70-100 per megawatt-hour.

Cheapest option

Electricity from new-build wind in Australia currently costs around A$60 per MWh, while PV power costs about A$70 per MWh.

During the 2020s these prices are likely to fall still further – to below A$50 per MWh, judging by the lower-priced contracts being signed around the world, such as in Abu DhabiMexicoIndia and Chile.

In our research, published today, we modelled the all-in cost of electricity under three different scenarios:

  • Renewables: replacement of enough old coal generators by renewables to meet Australia’s Paris climate target
  • Gas: premature retirement of most existing coal plant and replacement by new gas generators to meet the Paris target. Note that gas is uncompetitive at current prices, and this scenario would require a large increase in gas use, pushing up prices still further.
  • Status quo: replacement of retiring coal generators with supercritical coal. Note that this scenario fails to meet the Paris target by a wide margin, despite having a similar cost to the renewables scenario described above, even though our modelling uses a low coal power station price.

The chart below shows the all-in cost of electricity in the 2020s under each of the three scenarios, and for three different gas prices: lower, higher, or the same as the current A$8 per gigajoule. As you can see, electricity would cost roughly the same under the renewables scenario as it would under the status quo, regardless of what happens to gas prices.

Graphs of the Levelised cost of electricity (A$ per MWh) for three scenarios and a range of gas prices.
Levelised cost of electricity (A$ per MWh) for three scenarios and a range of gas prices. Blakers et al.

Balancing a renewable energy grid

The cost of renewables includes both the cost of energy and the cost of balancing the grid to maintain reliability. This balancing act involves using energy storage, stronger interstate high-voltage power lines, and the cost of renewable energy “spillage” on windy, sunny days when the energy stores are full.

The current cost of hourly balancing of the National Electricity Market (NEM) is low because the renewable energy fraction is small. It remains low (less than A$7 per MWh) until the renewable energy fraction rises above three-quarters.

The renewable energy fraction in 2020 will be about one-quarter, which leaves plenty of room for growth before balancing costs become significant.

Graph of the Cost of hourly balancing of the NEM (A$ per MWh) as a function of renewable energy fraction.
Cost of hourly balancing of the NEM (A$ per MWh) as a function of renewable energy fraction.

The proposed Snowy 2.0 pumped hydro project would have a power generation capacity of 2GW and energy storage of 350GWh. This could provide half of the new storage capacity required to balance the NEM up to a renewable energy fraction of two-thirds.

The new storage needed over and above Snowy 2.0 is 2GW of power with 12GWh of storage (enough to provide six hours of demand). This could come from a mix of pumped hydro, batteries and demand management.

Stability and reliability

Most of Australia’s fossil fuel generators will reach the end of their technical lifetimes within 20 years. In our “renewables” scenario detailed above, five coal-fired power stations would be retired early, by an average of five years. In contrast, meeting the Paris targets by substituting gas for coal requires 10 coal stations to close early, by an average of 11 years.

Under the renewables scenario, the grid will still be highly reliable. That’s because it will have a diverse mix of generators: PV (26GW), wind (24GW), coal (9GW), gas (5GW), pumped hydro storage (5GW) and existing hydro and bioenergy (8GW). Many of these assets can be used in ways that help to deliver other services that are vital for grid stability, such as spinning reserve and voltage management.

Because a renewable electricity system comprises thousands of small generators spread over a million square kilometres, sudden shocks to the electricity system from generator failure, such as occur regularly with ageing large coal generators, are unlikely.

Neither does cloudy or calm weather cause shocks, because weather is predictable and a given weather system can take several days to move over the Australian continent. Strengthened interstate interconnections (part of the cost of balancing) reduce the impact of transmission failure, which was the prime cause of the 2016 South Australian blackout.

Since 2015, Australia has tripled the annual deployment rate of new wind and PV generation capacity. Continuing at this rate until 2030 will let us meet our entire Paris carbon target in the electricity sector, all while replacing retiring coal generators, maintaining high grid stability, and stabilising electricity prices.


This article was co-authored by:
Image of Andrew Blakers Andrew Blakers – [Professor of Engineering, Australian National University];
 
Image of Bin LuBin Lu – [PhD Candidate, Australian National University]
and
Image of Matthew StocksMatthew Stocks – [Research Fellow, ANU College of Engineering and Computer Science, Australian National University]

 

 

 

 

 

This article is part of a syndicated news program via

New research suggests common herbicides are linked to antibiotic resistance

 New Zealand researchers have found that the 
active ingredients in commonly-used weed killers like Round-up and Kamba 
can cause bacteria to become less susceptible to antibiotics.

Antibiotics are losing their ability to kill bacteria.

One of the main reasons for the rise in antibiotic resistance is the improper use of antibiotics, but our latest research shows that the ingredients in commonly-used weed killers like Round-up and Kamba can also cause bacteria to become less susceptible to antibiotics.

Herbicides induce gene activity

Already, about 700,000 deaths are attributable each year to infections by drug-resistant bacteria. A recent report projected that by 2050, 10 million people a year will die from previously treatable bacterial infections, with a cumulative cost to the world economy of $US100 trillion.

The bacteria we study are potential human pathogens. Seventy years ago pathogens were uniformly susceptible to antibiotics used in medicine and agriculture. That has changed. Now some are resistant to all but one or two remaining antibiotics. Some strains are resistant to all.

When bacteria were exposed to commercial herbicide formulations based on 2,4-D, dicamba or glyphosate, the lethal concentration of various antibiotics changed. Often it took more antibiotic to kill them, but sometimes it took less. We showed that one effect of the herbicides was to induce certain genes that they all carry, but don’t always use.

These genes are part of the so-called “adaptive response”. The main elements of this response are proteins that “pump” toxins out of the cell, keeping intracellular concentrations sublethal. We knew this because the addition of a chemical inhibitor of the pumps eliminated the protective effect of the herbicide.

In our latest work, we tested this by using gene “knockout” bacteria, which had been engineered to lose just one pump gene. We found that most of the effect of the herbicide was explained by these pumps.

Reduced antibiotic use may not fix the problem

For decades we have put our faith in inventing new antibiotics above the wisdom of preserving the effectiveness of existing ones. We have applied the same invention incentives to the commercialisation of antibiotics as those used with mobile phones. Those incentives maximise the rate of product sales. They have saturated the market with phones, and they saturate the earth with antibiotic resistant bacteria.

Improper use of antibiotics is a powerful driver of the widespread resistance. Knowing this naturally leads to the hypothesis that proper and lower use will make the world right again. Unfortunately, the science is not fully on the side of that hypothesis.

Studies following rates of resistance do generally find a decrease in resistance to specific drugs when their use is banned or decreased. However, the effect is not a restoration of a pre-antibiotic susceptibility, characterised by multi-year effectiveness of the antibiotic. Instead, resistance returns rapidly when the drug is used again.

This tells us that once resistance has stablised in populations of bacteria, suspended use may change the ratio of resistant to susceptible but it does not eliminate resistant types. Very small numbers of resistant bacteria can undermine the antibiotic when it is used again.

Herbicides and other pollutants mimic antibiotics

What keeps these resistant minorities around? Recall that bacteria are very small, but there are lots of them; you carry 100 trillion of them. They are also found deep underground to high up in the atmosphere.

Because antibiotics are so powerful, they eliminate bacteria that are susceptible and leave the few resistant ones to repopulate. Having done so, we now have lots of bacteria, and lots of resistance genes, to get rid of, and that takes a lot of time.

As our work suggests, the story is even more complicated. We are inclined to think of antibiotics as medicine and agrichemicals, hand soaps, bug sprays and preservatives as different. Bacteria don’t do this. To them, they are all toxic.

Some are really toxic (antibiotics) and some not so much (herbicides). Bacteria are among the longest lived organisms on earth. Nearly four billion years of survival has taught them how to deal with toxins.

Pesticides as antibiotic vaccines

Our hypothesis is that herbicides immunise the bacteria from more toxic toxins like antibiotics. Since all bacteria have these protections, the use of widely used products to which they are exposed is particularly problematic. So these products, among others, might keep bacteria ready for antibiotics whether or not we are using them.

We found that both the purified active ingredients and potential inert ingredients in weed killers caused a change in antibiotic response. Those inert ingredients are also found in processed foods and common household products. Resistance was caused below legally allowed food concentrations.

What does this all mean? Well for starters we may have to think more carefully about how to regulate chemical commerce. With approximately eight million manufactured chemicals in commerce, 140,000 new since 1950, and limited knowledge of their combination effects and breakdown products, this won’t be easy.

But neither is it easy to watch someone die from an infection we lost the power to cure.


This article was written by:
Image of Jack HeinemannJack Heinemann – [Professor of Molecular Biology and Genetics, University of Canterbury]

 

 

 

 

 

Australia is a global top-ten deforester – and Queensland is leading the way

 A chain used for land clearing is dragged over  
a pile of burning wood on a drought effected property near St George, 
Queensland. AP Image/Dan Peled

When you think of devastating deforestation and extinction you usually think of the Amazon, Borneo and the Congo. But eastern Australia ranks alongside these in the top 10 of the world’s major deforestation fronts – the only one in a developed nation. Most of the clearing is happening in Queensland, and it is accelerating.

Only last year a group of leading ecologists voiced their alarm at new data which showed the clearing of 296,000 hectares of forest in 2013-14. This was three times higher than in 2008-09, kicking Australia up the list as one of the world’s forest-clearing pariahs. At the 2016 Society for Conservation Biology Conference, a Scientists’ Declaration was signed by hundreds of scientists, expressing concern at these clearing rates.

But the latest snapshot, Queensland’s Department of Science report on land cover change published last month, showed a staggering 395,000ha of clearing for 2015-16: a 133% increase on 2014-15. As far as we can tell this rate of increased clearing is unmatched anywhere else on the globe.

Strong vegetation management laws enacted in Queensland – the Vegetation Management Act 1999 – achieved dramatic reductions in forest and woodland loss. But the subsequent Liberal National state government, elected in 2012, overturned these protections.

The current government, elected in 2015, has tried and failed to reinstate the protections. In response, “panic clearing” caused clearing rates to shoot up, in anticipation that the state election will deliver a government that will reintroduce the much-needed protection of forests.

The Queensland Parliament is now in caretaker mode ahead of the November 25 election. The Queensland Labor Party has pledged to reinstate laws to prevent wholesale clearing, while the LNP opposition has vowed to retain current clearing rates.

Picture of deforestation
Forest cleared by bulldozers towing massive chains. Noel Preece

Australian community and wildlife lose

Whichever way you look at it, there is not a lot of sense in continued clearing. Australia already has some of the highest extinction rates on the planet for plants and animals. With 80% of Queensland’s threatened species living in forest and woodland, more clearing will certainly increase that rate.

Clearing also kills tens of millions of animals across Australia each year, a major animal welfare concern that rarely receives attention. This jeopardises both wildlife and the A$140 million invested in threatened species recovery.

This rate of clearing neutralises our major environment programs. Just one year of clearing has removed more trees than the bulk of 20 million trees painstakingly planted, at a cost of A$50 million. Australia’s major environment programs simply can’t keep up, and since 2013 are restoring only one-tenth of the extent of land bulldozed just last year.

Restoration costs to improve the quality of waters running onto the Great Barrier Reef are estimated at around A$5 billion to A$10 billion over 10 years. Nearly 40% of the land cleared in Queensland is in reef catchments, which will reverse any water quality gains as sediment pours onto the reef.

Climate efforts nullified

Since 2014, the federal government has invested A$2.55 billion on reducing emissions in the Carbon Farming Initiative through the Emissions Reduction Fund. Currently 189 million tonnes of abatement has been delivered by the Emissions Reduction Fund. This – the central plank of the Australian government’s climate response – will be all but nullified by the end of 2018 with the current clearing rates, and will certainly be wiped out by 2020, when Australia is expected to meet its climate target of 5% below 2000 emissions.

Ironically, this target will be achieved with the help of carried-over results from the first commitment period of the Kyoto Protocol, which Australia was only able to meet because land clearing had decreased between 1990 and 1997.

Why is this happening?

Most of the clearing in Queensland since 1999 has been for pasture. Most good cropping land was cleared decades ago. Removing trees in more marginal lands can increase the carrying capacity for a short time with an immediate, and usually short-lived, financial reward. These rewards come at the expense of long-term sustainability, which future landholders and government will bear.

Large areas of the cleared lands have been subject to substantial erosion and nutrient lossfrom the newly cleared lands, and land degradation over time, and some areas have suffered massive woody weed incursions.

This is playing out today across the north where pastoralism is a marginal activity at best, with declining terms of trade of about 2% per year, with no net productivity growth, high average debts and low returns, and many enterprises facing insolvency. Clearing vegetation won’t change that.

A recent preliminary valuation of ecosystem services, on the other hand, estimated that uncleared lands are worth A$3,300-$6,100 per hectare per year to the Australian community, compared with productivity of grazing lands of A$18 per hectare.

With a clear divide between the policies Labor and the LNP are taking to the election, now is a good time to give land clearing’s social, economic and environmental impact the scrutiny it deserves.


This article was co-authored by:
Image of Noel D PreeceNoel D Preece – [Adjunct Principal Research Fellow at Charles Darwin and, James Cook University]
and
Image of Penny van OosterzeePenny van Oosterzee – [Principal Research Adjunct James Cook University and University Fellow Charles Darwin University, James Cook University]

 

 

 

 

 

This article is part of a syndicated news program via

Fossil fuel emissions hit record high after unexpected growth: Global Carbon Budget 2017

 The growth in global carbon emissions has
resumed after a three-year pause. AAP Image/Dave Hunt

Global greenhouse emissions from fossil fuels and industry are on track to grow by 2% in 2017, reaching a new record high of 37 billion tonnes of carbon dioxide, according to the 2017 Global Carbon Budget, released today.

The rise follows a remarkable three-year period during which global CO₂ emissions barely grew, despite strong global economic growth.

But this year’s figures suggest that the keenly anticipated global peak in emissions – after which greenhouse emissions would ultimately begin to decline – has yet to arrive.

The Global Carbon Budget, now in its 12th year, brings together scientists and climate data from around the world to develop the most complete picture available of global greenhouse gas emissions.

In a series of three papers, the Global Carbon Project’s 2017 report card assesses changes in Earth’s sources and sinks of CO₂, both natural and human-induced. All excess CO₂ remaining in the atmosphere leads to global warming.

We believe society is unlikely to return to the high emissions growth rates of recent decades, given continued improvements in energy efficiency and rapid growth in low-carbon energies. Nevertheless, our results are a reminder that there is no room for complacency if we are to meet the goals of the Paris Agreement, which calls for temperatures to be stabilised at “well below 2℃ above pre-industrial levels”. This requires net zero global emissions soon after 2050.

Graph of 2017 emissions
After a brief plateau, 2017’s emissions are forecast to hit a new high. Global Carbon Project, Author provided

National trends

The most significant factor in the resumption of global emissions growth is the projected 3.5% increase in China’s emissions. This is the result of higher energy demand, particularly from the industrial sector, along with a decline in hydro power use because of below-average rainfall. China’s coal consumption grew by 3%, while oil (5%) and gas (12%) continued rising. The 2017 growth may result from economic stimulus from the Chinese government, and may not continue in the years ahead.

The United States and Europe, the second and third top emitters, continued their decade-long decline in emissions, but at a reduced pace in 2017.

For the US, the slowdown comes from a decline in the use of natural gas because of higher prices, with the loss of its market share taken by renewables and to a lesser extent coal. Importantly, 2017 will be the first time in five years that US coal consumption is projected to rise slightly (by about 0.5%).

The EU has now had three years (including 2017) with little or no decline in emissions, as declines in coal consumption have been offset by growth in oil and gas.

Unexpectedly, India’s CO₂ emissions will grow only about 2% this year, compared with an average 6% per year over the past decade. This reduced growth rate is likely to be short-lived, as it was linked to reduced exports, lower consumer demand, and a temporary fall in currency circulation attributable to demonetisation late in 2016.

Graph showing -Trends for the biggest emitters, and everyone else.
Trends for the biggest emitters, and everyone else. Global Carbon Project, Author provided

Yet despite this year’s uptick, economies are now decarbonising with a momentum that was difficult to imagine just a decade ago. There are now 22 countries, for example, for which CO₂ emissions have declined over the past decade while their economies have continued to grow.

Concerns have been raised in the past about countries simply moving their emissions outside their borders. But since 2007, the total emissions outsourced by countries with emissions targets under the Kyoto Protocol (that is, developed countries, including the US) has declined.

This suggests that the downward trends in emissions of the past decade are driven by real changes to economies and energy systems, and not just to offshoring emissions.

Other countries, such as Russia, Mexico, Japan, and Australia have shown more recent signs of slowdowns, flat growth, and somewhat volatile emissions trajectories as they pursue a range of different climate and energy policies in recent years.

Still, the pressure is on. In 101 countries, representing 50% of global CO₂ emissions, emissions increased as economies grew. Many of these countries will be pursuing economic development for years to come.

Contrasting fortunes among some of the world’s biggest economies. Nigel Hawtin/Future Earth Media Lab/Global Carbon Project, Author provided

A peek into the future

During the three-year emissions “plateau” – and specifically in 2015-16 – the accumulation of CO₂ in the atmosphere grew at a record high that had not previously been observed in the half-century for which measurements exist.

It is well known that during El Niño years such as 2015-16, when global temperatures are higher, the capacity of terrestrial ecosystems to take up CO₂ (the “land sink”) diminishes, and atmospheric CO₂ growth increases as a result.

The El Niño boosted temperatures by roughly a further 0.2℃. Combined with record high levels of fossil fuel emissions, the atmospheric CO₂ concentration grew at a record rate of nearly 3 parts per million per year.

This event illustrates the sensitivity of natural systems to global warming. Although a hot El Niño might not be the same as a sustained warmer climate, it nevertheless serves as a warning of the global warming in store, and underscores the importance of continuing to monitor changes in the Earth system.

Graph showing - The effect of the strong 2015-16 El Niño on the growth of atmospheric CO₂
The effect of the strong 2015-16 El Niño on the growth of atmospheric CO₂ can clearly be seen. Nigel Hawtin/Future Earth Media Lab/Global Carbon Project, based on Peters et al., Nature Climate Change 2017, Author provided

No room for complacency

There is no doubt that progress has been made in decoupling economic activity from CO₂ emissions. A number of central and northern European countries and the US have shown how it is indeed possible to grow an economy while reducing emissions.

Other positive signs from our analysis include the 14% per year growth of global renewable energy (largely solar and wind) – albeit from a low base – and the fact that global coal consumption is still below its 2014 peak.

These trends, and the resolute commitment of many countries to make the Paris Agreement a success, suggest that CO₂ emissions may not return to the high-growth rates experienced in the 2000s. However, an actual decline in global emissions might still be beyond our immediate reach, especially given projections for stronger economic growth in 2018.

To stabilise our climate at well below 2℃ of global warming, the elusive peak in global emissions needs to be reached as soon as possible, before quickly setting into motion the great decline in emissions needed to reach zero net emissions by around 2050.


This article was co-authored by the following international team pf scientists:

 

 

 

 

 

 

This is what Australia’s growing cities need to do to avoid running dry

 The Thomson Dam, Melbourne’s largest water  
storage, dropped to only 16% of capacity in the last big drought.
Melbourne Water

The increasing thirst of Australia’s biggest cities routinely exceeds our capacity to rely on rainfall for drinking water. Australia is facing a fast-approaching “perfect storm” of growing urban populations and declining rainfall to supply storage reservoirs.

Despite these challenges, our capital cities’ rapid population growth is forecast to continue in coming decades. Sydney, for example, is expected to grow by 1.6 million people in 20 years, but is predicted to be overtaken by Melbourne as the nation’s largest city by then.

How is Australia going to ensure the swelling urban population has enough water? The last two decades provide some important clues.

The largest east coast centres (Melbourne, Canberra, Brisbane and Sydney) have all faced water supply challenges, but Perth and Adelaide have really been pushed to extreme levels. Current water storage levels in Australian capital cities range from 94.2% in Hobart and 69.7% in Melbourne through to 40.4% in Perth – the lowest of the capital cities. Only a year ago it was an alarming 28.5%.

Why are Perth’s water storages so low? Because of steep declines in rainfall and catchment runoff into the city’s dams.

The world is watching Perth and its water supply crisis. The long-term volume of water flowing into the Perth supply has plummeted from an annual average of 338 gigalitres (1911 to 1974) to less than 50 GL/year (2010-2016). During this 43-year “big dry”, the number of people served by the Perth water supply has increased steeply.

How has Perth managed to survive? Desalination and groundwater have come to the rescue. Perth relies less on catchment runoff and surface storages, and now has two giant desalination plants. It also has tapped into groundwater as a major source of domestic water.

Solutions have been costly

All water utilities across Australia struggle with increased population growth and extended periods of low rainfall. The Millennium Drought caused widespread problems for all Australian urban water supplies. The levels in major east coast storages shrivelled to the lowest levels in decades.

Melbourne’s water storages fell to a perilous low of 26% in June 2009. A large part of Adelaide’s water supply has relied on declining flows in the Murray River. The drought combined with extractions by upstream water users reduced the Murray to a trickle in 2006-07.

All of the mainland states have built huge desalination plants, but these come with huge price tags. The Melbourne plant cost about A$4 billion.

Operational costs are enormous, even if the plants sit idle. The Sydney plant’s costs are more than A$500,000 a day, although it has not supplied any water since 2012 as the city’s stored water supply remains higher than 60% of capacity.

Desalination also uses enormous quantities of electricity to extract fresh water from salt water. During his time as NSW premier, Bob Carr referred to desalination as “bottled electricity”. This is important to consider given the power crisis facing eastern Australia.

Urban growth affects water quality

The growth of the urban populations and other human activities is linked to water quality issues in urban water supplies. Melbourne’s water catchments are mostly “closed” – minimal private landholdings and human activity are permitted. In contrast, Sydney and Brisbane have more “open” catchments, which include private lands.

Three Brisbane storages (Wivenhoe, North Pine and Somerset) have water quality issues linked to agriculture and other human activity in the catchments. Sydney’s massive Warragamba Dam has a huge catchment that includes more than 110,000 people. The settlements are served by nine sewage treatment plants, most of which discharge treated sewage into drinking water catchment rivers.

Picture of a drying Warragamba Dam
New South Wales’ hydroelectric Warragamba Dam. Taras Vyshnya / Shutterstock

A recent audit of the Sydney catchments and storages reported that sewage treatment plant upgrades had improved water quality. The audit recommended that future upgrades improve sewage treatment for the growing urban population in the NSW Southern Highlands (Bowral, Mittagong and Moss Vale).

The case for water conservation and recycling

Perth and Adelaide are the two capitals under most water supply stress. They are an example for all Australian capitals to consider when planning future water supply challenges and solutions. Both Perth and Adelaide now heavily rely on recycled water and desalination.

Recycling waste water for use in urban water supplies is important for all urban centres, particularly Perth and Adelaide. The United Nations Food and Agriculture Organization points out that waste water has numerous public health risks, so risk management is essential for all recycled water schemes.

Perth and Adelaide are both using more groundwater than the other capital cities. Perth is extracting more groundwater from deep aquifers north of the city. Perth is also pumping treated waste water into shallower groundwater aquifers to replenish the supply.

No new large water supply dam has been built in Australia since the 1980s. The challenge of meeting future urban water demand is not likely to be solved by building new dams.

While desalination, groundwater and recycling are all growing in importance, our individual actions to conserve and use less water are key. For example, the consumption of water per person in Sydney has dropped from 500 litres a day in 1990 to less than 300 litres. Melbourne has a daily target of 155 litres per person.

There is plenty of room for improvement. According to United Nations data, Australia still has the second-highest daily water consumption per person. The US has the world’s highest at 575 litres a day. The UK is already exceeding Melbourne’s target with 149 litres per day. Tragically, in Mozambique, water is in such short supply that people there use a paltry four litres per day.


This article was written by:

Ian Wright– [Senior Lecturer in Environmental Science, Western Sydney University]

 

 

 

 

This article is part of a syndicated news program via

 

Buying fresh potatoes and carrots all year round is destroying Australia’s soil

 Producing fresh fruit and vegetables 
year-round has a hidden cost. 

Have you thought about what it takes to get fresh carrots onto supermarket shelves during winter?

We all want fresh carrots rather than soft, old or bendy ones. That’s why many companies – such as supermarkets that tout their “fresh food” credentials – build their brand around providing crisp, fresh veggies all year round.

Unfortunately, consumers’ expectations that certain types of produce will always be available mean that farmers must engage in unsustainable and destructive practices.

Carrots are collected using mechanised harvesters, heavy tractors and trucks. In winter, during seasonal rainfall peaks, the combination of wet earth and heavy machinery results in severe soil compaction and soil structure degradation.

Studies have shown that this degradation can last for decades. This reduces the soil’s fertility and ultimately reduces crop yields.

Soil degradation

Soil degradation has serious impacts on the sustainability and profitability of Australian farms. A 2004 Tasmanian study found that soil degradation reduced potato and poppy crop yields by up to two-thirds. Carrots and potatoes are not alone in winter soil degradation; broccoli, cabbages and peas are often harvested when soils are too wet.

The other three main issues of degradation are declining soil organic matter levels, soil loss by erosion, and nutrient imbalances.

Soil organic matter plays a fundamental role in soil’s physical, chemical and biological processes, but its decline under Australian agriculture has been well researched and widely reported.

The use of green manure cover crops (crops that aren’t harvested) and grass pastures in rotations that provide greater organic matter residues can help. But farmers may struggle to afford the ongoing investment required to improve long-term sustainability.

Whether caused by wind or water erosion, soil loss is permanent. Heavy losses occurred in Sydney, Brisbane and Canberra in 2009, and Melbourne in 1983. The fine particles and organic matter lost in dust storms are the most important for soil fertility.

As former Nebraskan governor Bob Kerrey once said:

If you run out of water, you pray for rain. If you run out of soil, you pray for forgiveness.

The third element is soil nutrients. The main factors here are soil pH, plant-available phosphorus, potassium and sulphur. A study of 1,700 intensively grazed pasture paddocks found that only 3.7% had the optimum balance for pasture production. More than 40% had too much phosphorus and potassium.

Intensive farming means increased amounts of nutrients and sediment end up polluting off-site surface water. Nutrient loss at catchment scales has been reported in southeastern Australia, with phosphorus losses of 10–12kg per hectare per year and nitrogen losses of 20–30kg per hectare per year, which are at the higher end of published values.

However, these losses may be under-reported by as much as 50%, as the sampling misses flood events. Land management is important to reduce the total nutrient and sediment delivery to rivers. But even with the best management practices, nutrients and sediments will still be delivered at higher than natural rates.

A better way

Some solutions to this problem lie in better technology and education. For example, using the right fertilisers at the right time can help with nutrient imbalances.

GPS guidance on agricultural machinery can restrict damage to soil structure to strict lines in paddocks (known as tramlines). This technology is increasingly used across a range of cropping industries, but there are significant barriers to its universal uptake in the vegetable industry.

It is important to remember that simply making information available, especially via online portals, will not necessarily result in farmers adopting sustainable practices. Farmers often need to trust those with new ideas before change happens.

But the other part of the solution is consumer demand. The pressure on our natural resources is mounting. Projected increases in global food demand over the next 50 years pose huge challenges for sustainable production.

While many shoppers want their food to be sustainably grown, we also generally expect certain produce – carrots, potatoes and broccoli – to show up, gleaming fresh, in our supermarkets. Understanding the cost of off-season harvesting, and separating the “fresh food” marketing from reality, is the first step to more sustainable consumption.


This article was written by:
Image of Bill Cotching Bill Cotching – [Soil scientist, University of Tasmania]

 

 

 

 

 

This article is part of a syndicated news program via

Why hot weather records continue to tumble worldwide

 
Extreme temperatures in Cordoba, Spain in June 2017

It sometimes feels like we get a lot of “record-breaking” weather. Whether it’s a heatwave in Europe or the “Angry Summer” in Australia, the past few years have seen temperature records tumble.

This is the case both locally – Sydney had its hottest year on record in 2016 – and globally, with the world’s hottest year in 2016 beating the record set only the year before.

Some of 2016’s heat was due to the strong El Niño. But much of it can be linked to climate change too.

We’re seeing more heat records and fewer cold records. In Australia there have been 12 times as many hot records as cold ones in the first 15 years of this century.

If we were living in a world without climate change, we would expect temperature records to be broken less often as the observational record grows longer. After all, if you only have five previous observations for annual temperatures then a record year isn’t too surprising, but after 100 years a new record is more notable.

In contrast, what we are seeing in the real world is more hot temperature records over time, rather than less. So if you think we’re seeing more record-breaking weather than we should, you’re right.

Why it’s happening

In my new open-access study published in the journal Earth’s Future, I outline a method for evaluating changes in the rate at which temperature records are being broken. I also use it to quantify the role of the human influence in this change.

To do it, I used climate models that represent the past and current climate with both human influences (greenhouse gas and aerosol emissions) and natural influences (solar and volcanic effects). I then compared these with models containing natural influences only.

Lots of hot records, fewer cold ones

Taking the example of global annual temperature records, we see far more record hot years in the models that include the human influences on the climate than in the ones without.

Crucially, only the models that include human influences can recreate the pattern of hot temperature records that were observed in reality over the past century or so.

Observed and model-simulated numbers of hot and cold global annual temperature records for 1861-2005. Observed numbers of record occurrences are shown as black circles with the model-simulated record numbers under human and natural influences (red box and whiskers) and natural influences only (orange box and whiskers) also shown. The central lines in the boxes represent the median; the boxes represent interquartile range. Author provided

In contrast, when we look at cold records we don’t see the same difference. This is mainly because cold records were more likely to be broken early in the temperature series when there were fewer previous data. The earliest weather data comes from the late 19th century, when there was only a weak human effect on the climate relative to today. This means that there is less difference between my two groups of models.

In the models that include human influences on the climate, we see an increase in the number of global record hot years from the late 20th century onwards, whereas this increase isn’t seen in the model simulations without human influences. Major volcanic eruptions reduce the likelihood of record hot years globally in both groups of model simulations.

Projecting forward to 2100 under continued high greenhouse gas emissions, we see the chance of new global records continuing to rise, so that one in every two years, on average, would be a record-breaker.

Chance of record hot global annual temperatures in climate models with human and natural influences (red) and natural influences only (orange). Grey curve shows the statistical likelihood of a new hot record each year (100% in the first year, 50% in the second year, 33% in the third year, and so on). Grey vertical bars show the timing of major volcanic eruptions through the late-19th and 20th centuries. Author provided

I also looked at specific events and how much climate change has increased the likelihood of a record being broken.

I used the examples of the record hot years of 2016 globally and 2014 in Central England. Both records were preceded by well over a century of temperature observations, so in a non-changing climate we would expect the chance of a record-breaking year to be less than 1%.

Instead, I found that the chance of setting a new record was increased by at least a factor of 30 relative to a stationary climate, for each of these records. This increased likelihood of record-breaking can be attributed to the human influence on the climate.

More records to come?

The fact that we’re setting so many new hot records, despite our lengthening observation record, is an indicator of climate change and it should be a concern to all of us.

The increased rate at which we are getting record hot temperatures is controlled by the speed of global warming, among other factors. To meet the Paris target of keeping global warming below 2℃ we will have to reduce our greenhouse gas emissions drastically. Besides keeping average global temperatures under control, this would also reduce the chance of temperature records continuing to tumble, both globally and locally.


This article was written by:
Image of Andrew King

 

 

 

 

 

Drop, bears: chronic stress and habitat loss are flooring koalas

 Koalas are stressed out by a range of  
pressures, from habitat loss to dog attacks. Edward Narayan

Koalas are under a lot of stress. Heatwavesland clearing and even noise pollution are all taking a toll.

Each year, hundreds of koalas are taken to veterinary clinics after being rescued from roadsides or beneath trees, and the incidences increase during the summer months.

Chronic and ongoing pressures such as habitat destruction are overwhelming koalas’ ability to cope with stress. Koalas are nationally listed as vulnerable, so it’s important to understand how they are affected by threats that can reduce life expectancy and their ability to cope with problems.

What is stress?

The term “stress” was coined in 1936 by Hans Sayle after experiments on rats. Sayle demonstrated that the adrenal glands, which sit on top of the kidney and produce the stress hormones adrenaline and cortisol, can swell in response to any noxious stimulus or due to pathological state. In addition, there are changes in the tissues and glands involved in the basic functioning of the immune system, reproduction and growth.

The short-term stress response is not necessarily bad, because it prepares the body to cope with external challenges. For example, tadpoles that are exposed to dragonfly nymphs grow larger and have bigger tail fins than other tadpoles.

However, chronic stress over a long time can seriously affect an animal’s health (humans included) and survival rates.

How do koalas respond to stress?

Koalas release the stress hormone cortisol in response to any unpleasant stimulus like being handled by humans (oddly, males are much more stressed by handling than females, unless the females are lactating).

Koalas have biological feedback mechanisms that can regulate the amount of cortisol they produce, so they can carry on with their day-to-day routine. However, if koalas are continuously stressed by something large and permanent, such as land clearing of their territory, it’s difficult for them to relax from a stressed state.

When this happens, the body undergoes a barrage of sub-lethal chemical changes. The resulting chronic stress can negatively affect the animals’ reproductive hormones and immune system function.

Koalas, like all animals that call Australia home, have basic physiological and behavioural adaptations needed for life in Australia’s often extreme environment. But human-induced threats such as land clearing continue to create ecological imbalances, and chronic stress makes it very difficult for koalas to cope with environmental change.

How much stress can a koala bear?

As my review of the research shows, the most common sources of stress for koalas are heat stress, car impacts and dog attacks. Foetal development of koalas could also be impacted by maternal stress due to lack of adequate food from gum trees in drought periods.

Urban and fringe zones (areas between rural and urban zones) are particularly stressful for koalas, with added pressures like noise pollution and a higher chance of land clearing.

All of these factors create a continual strain on koala physiology. The sight of a koala dead by the road is the distressing culmination of multiple, complex and dynamic environmental influences.

Clinical research has shown that wild koalas are suffering from chronic stress. Koalas are often rescued with signs of trauma, caused by car accidents, burns or dog attacks, which is very difficult to handle in veterinary clinics.

Koalas are a living treasure, the only extant representative of the family Phascolarctidae. They live exclusively on Australia’s east coast, but are considered rare in New South Wales and South Australia.

There are now numerous local dedicated koala conservation centres aimed at safeguarding their habitat and educating the public. Koalas also help increase public awareness of conservation among both young people and adults.

But more research is needed in studying how they respond to the stresses of life in a human-dominated landscape. Techniques such as non-invasive hormone monitoring technology can be used to provide a rapid and reliable index of how our koalas are being affected by stress.

Simply put, if land clearing is not reduced now we will continue to add invisible stress on koalas. Our children may one day be more likely to see a koala dead on the road than one happily cuddling their gum tree.


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Victoria’s plastic bag ban: a good start, but we can do more

 The Victorian government has  
a new proposal to ban plastic bags. What is it missing? suvajit/pixabay

The Victorian government is proposing to ban single-use lightweight plastic shopping bags.

First of all, for plastic bag devotees, don’t panic – there are alternatives such as paper, cloth and a range of other reusable bags (you can even use the cardboard cartons from the shop). For those who have been advocating for a ban, don’t relax – there is still more to be done.

While the details of the plan are still being discussed, it is good to see that the government has committed to consultation with businesses and the community. We can be assured that the government will not swap one issue for another – such as reducing the amount of plastic bags used for waste, only to increase the use of bin liners. We need to ensure that the alternatives proposed actually reduce environmental impact.

In fact, this is prime time for the government to take a step further. We can do much more than ban single-use plastic bags. We should expand the ban to cover more categories of plastic and actively move to manage waste and reduce plastic pollution.

Should the ban proceed, it will have one significant outcome. The three most common contaminants of the household recycling bin (representing 10-15% of the recycling stream, according to my own audits of kerbside recycling bins) will be banned:

  • plastic bags with recyclables
  • plastic bags with general waste
  • empty plastic bags.

But simply looking at the perceived issues associated with plastic bag disposal is not enough. We must also understand why people actually use plastic bags. What are their shopping habits? When do they shop? Have we considered tourists who buy groceries?

Plastics ban is not enough

Instead of just banning bags, we need to look at the issue of plastic in its broadest sense. On a recent trip to the supermarket, I estimated that almost 40% of the vegetables are wrapped in plastic packaging. Even if you wanted an alternative, sometimes there isn’t one. The packaging comes with the produce.

Picture of cucumbers wrapped in clear plastic
Excessive plastic packaging around groceries. Is it necessary? Anna Gregory/flickr

The Victorian government has claimed that it would be impractical to ban the packaging of fruit and vegetables. But why is it acceptable to focus only on the plastic in bags and not in other vessels? Packaging is another source of excess plastic that consumes resources and contributes significantly to landfill waste. Given that many foods (such as strawberries or tomatoes) are pre-packaged, shoppers will often buy more than they need and end up wasting food.

We have the perfect opportunity to address two significant issues at the same time. The question is: will we?

The Victoria government has acknowledged that thicker, more durable plastic bags have a greater environmental impact. Yet according to the proposed policy, the banning of these bags may be optional. This is why any consultation process must encompass all types of plastic.

Picture of rows of fruit all wrapped in plastic
Is all this plastic really necessary? Anna Gregroy/flick

We have the opportunity to get it right and lead the way, and it is important that all views are heard. If you would like to have your say, the Victorian government has a survey where comments can be provided.

What we can learn from other programs

When looking at programs that successfully changed our behaviour, such as “slip slop slap”, using seatbelts and reducing the road toll, promoting HIV awareness, and even litter prevention, we can identify several features that seem to be crucial to their success. They are:

  • the program advised us exactly what to do and why
  • there were multiple different advertisements – but each focused on the same issue
  • different demographics were targeted, but with the same focus
  • the advertisements were provided in multiple formats at many locations.

It will be important that any action undertaken includes an education program. It should inform consumers why this ban is happening and advise them what actions they can take.

Other policies that we can undertake include container deposit legislation. My audits of SA’s landfill rates, compared with those of other states without container deposit schemes, shows that these schemes significantly reduce the disposal of plastic waste to landfill.

Picture of Victorian Environment Minister Lily D'Ambrosio
Victorian Environment Minister Lily D’Ambrosio outlines the proposed plastic bag ban. Joe Castro/AAP

These changes should be incorporated into the proposed ban of the plastic bags. We must learn from past policies to ensure we make a smooth transition away from disposable plastics. The government should be aware of the different shopping habits of our society to find a cost-effective yet sustainable solution to plastic packaging.

There are a lot of changes that we can make. It is not just limited to banning single-use plastic bags. We need to consider the bigger picture of plastic packaging so we can truly put a dent in retail waste.


This article was written by:
Trevor Thornton – [Lecturer, School of Life and Environmental Sciences, Deakin University]

 

 

 

 

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Bees in the city: Designing green roofs for pollinators

 Bees living in cities often have to seek  
out green space like parks, ravines and gardens. Green roofs could offer 
them some habitat. 

Declining bee populations have been widely covered in the news. It is a pressing issue worldwide as one in three bites of food that we eat relies on bee pollination.

A key factor that affects bees is increasing urban development as people flock to cities. As cities develop, they sprawl into their surroundings, fragmenting animal habitats and replacing vegetation with hard surfaces such as concrete and asphalt. Insects, including a multitude of native bees, rely on soil and plants for foraging and nesting.

Bee habitat and foraging opportunities become smaller and more distant from each other. These segments of green space have become known as “habitat patches,” disconnected pieces of habitat that animals can move between to achieve the effect of a larger ecosystem.

These patches occur in cities and can take the form of ravines, parks, gardens and so on.

Despite the fact that pollinators such as birds, bees and butterflies are better at moving between patches than less mobile species, a continuous habitat is always preferable. Green roofs are seen as a way to make up for ecological habitat fragmentation. But studies and guidelines about where and how to best construct green roofs for pollinators are just emerging.

Picture of A wild, non-native bee forages for pollen on the green roof of the University of Toronto’s GRIT Lab. 
A wild, non-native bee forages for pollen on the green roof of the University of Toronto’s GRIT Lab.  

Though domesticated bee species such as the well known European honey bee (Apis mellifera) tend to receive greater attention when it comes to declining population, wild bee species are often found to be even more threatened. Wild bee species are most commonly “solitary” as opposed to “social” and nest in the ground or in existing cavities, not hives.

Of the 20,000 or so known bee species, 85 per cent or more are solitary. Rapid urbanization, through paving extensive areas of our environment and loss of vegetative cover, is having a widespread harmful impact on their habitat.

Cities are beginning to recognize the importance of creating and enhancing healthy habitats for pollinator populations that support resilient ecosystems and contribute to a rich urban biodiversity.

The City of Toronto is in the process of developing a Pollinator Protection Strategyintended to raise awareness, develop new education and training, evaluate and investment in green spaces, as well as reexamine city maintenance practices.

Green roofs are mentioned in the Protection Strategy as one way cities can compensate for the loss of ecological habitat and provide valuable foraging opportunities for urban wildlife.

Native or non-native?

Research on the topic of green roofs as pollinator habitats has been fairly limited, but with cities like Toronto adopting bylaws that mandate green roof implementation, there’s an opportunity to study what design decisions are most critical to their success.

Green roof planting choices have been shown to play a part in attracting specific bee species. Sedum species, which are drought-tolerant succulent plants, have always been the most popular choice for green roofs due to their hardiness under extreme conditions, long flowering period and low maintenance requirements.

In fact, in Toronto, a great majority of green roofs are planted with sedum.

Research by University of Toronto Prof. Scott MacIvor and colleagues at the Green Roof Innovation Testing Lab (GRIT Lab) shows that when individual native bees visited sedum, their pollen loads contained other herbaceous flower sources, whereas non-native bees had more full pollen loads of sedum more often.

These findings suggest that if the majority of green roofs are planted strictly with non-native sedum varieties, it could result in a lost opportunity to bolster precious habitat for native pollinators.

It’s important to note that roughly 92 per cent of Toronto’s bee species are native. So, favouring non-native plants can provide habitat for non-native bees over native bees, and could consequently lead to increased competition for those native bees.

Site matters

Despite many green roofs being opportune places for bees to inhabit, research has shown that the location of the green roof matters. The higher the roof, the fewer bees were found there. Green roofs implemented above the eighth storey would not benefit from any additional nesting resources or attract bees.

This doesn’t mean that green roofs atop skyscrapers are useless, but that they should focus on other benefits such as rainwater retention, air quality improvement and thermal cooling.

In large cities like Toronto, many new high-rise buildings are being built with a “tower and podium” configuration, whereby the first few floors of the building have a wide floor area, often covering most of the block (podium), and the tower is set back from the edge of the building.

The roof of the podium is often used as communal space for the building’s occupants and presents a good spot for a biodiverse green roof that could serve bees’ needs. The study further shows that a decline in green space area within a 600-metre radius around each rooftop results in decreasing species richness (diversity) and abundance.

Toronto’s Old City Hall is seen from the green roof planted on the podium of the new City Hall. (Shutterstock)

Therefore, those designing pollinator habitats on green roofs should consider green space in the surrounding landscape and other features outlined in the City of Toronto Guidelines for Biodiverse Green Roofs.

Considerations and recommendations

Though the appeal of planting green roofs with sedum is evident, limiting the plant palette solely to sedum species could be a lost opportunity to promote native plant and pollinator species in urban environments.

At its worst, this practice could cause non-native bee species to have a leg up on natives as both groups compete for pollen.

It’s important to not only consider plant communities on green roofs, but also the building height and its proximity to other habitat patches to provide as much foraging habitat as possible for bees.

We still need new research into nesting opportunities for ground-nesting bees in the green roof growing medium, as well as the connectivity between ground level landscapes and green roofs, to better understand the ecological value of green roofs in sprawling urban regions.


This article was co-authored by:
Image of Catherine HowellCatherine Howell – [Research Assistant, GRIT Lab, University of Toronto];
 
Image of Jennifer DrakeJennifer Drake – [Assistant Professor of Civil Engineering, University of Toronto]
and
Image of Liat Margolis Liat Margolis – [Associate Professor of Landscape Architecture , University of Toronto]

 

 

 

 

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