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MEGAFAUNA EXTINCTION: Sabre-toothed cats, one-tonne bears and sloths the size of elephants all happily coexisted with humans for up to 3000 years, but were extinct within 300 years after the climate of South America rapidly warmed.

On the shorelines of the Yellow Sea, eight million shorebirds are probing the sediment for food, but their bellies are empty. Could their epic migration end here on this barren mudflat?

Rhino poachers in Mozambique target anti-poaching guards.

Research has found that despite having excellent quality water, 40 per cent of Sydneysiders don't drink water straight from the tap.

Ocean experts call for international action to generate the kinds of maps of global seabeds that space missions have already returned for the Moon and Mars.

A horde of giant spider crabs has amassed in waters near Melbourne. Australian aquatic scientist Sheree Marris filmed this incredible footage.

From soaring temperatures in Alaska and India to Arctic sea ice melting and CO2 concentrations rising, this year is smashing records around the world

1) Arctic sea ice is melting at a rate that by September could see it beat the record low set in 2012. The maximum extent of sea ice in winter was at a record low, and the extent in May was the lowest for that month ever, by more than 500,000 sq km.

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Unprecedented temperature levels mean more heatwaves, flooding, wildfires and hurricanes as experts say global warming is here and affecting us now

May was the 13th month in a row to break temperature records according to figures published this week that are the latest in 2016’s string of incredible climate records which scientists have described as a bombshell and an emergency.

Related: Seven climate records set so far in 2016

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The week’s top environment news stories and green events. If you are not already receiving this roundup, sign up here to get the briefing delivered to your inbox

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Arctic sea-ice may have hit a record low in May but that does not mean September will set a new minimum mark, say polar experts at Reading University, UK.

A crater on Mars is named Langtang, in tribute to one of the worst-hit villages during the 2015 Nepal earthquake.

Newly sequenced genomes of soil bacteria have led to questions about how differing land management affects the organisms' behaviour, on agriculture and emissions.

Its 170,000 pieces of aluminium are a hive-like structure of latticework, controlled by the vibrations of honeybees in a hive at Kew that is connected to the sculpture

“My approach to a sculpture seeks to frame nature so one can experience it more intimately,” says British artist Wolfgang Buttress, whose 17-metre high Hive installation opens at the Royal Botanical Gardens at Kew, in London on Saturday. “I want visitors to feel enveloped, wrapped-up and involved in the experience, rather than adopting the position of an external observer.”

Related: How much do you know about bees? - quiz

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Wildfires caused by high summer temperatures rage in Arizona, California and New Mexico. Communities have been evacuated with more on standby should the fires spread. Firefighting aircraft are leading the battle against the flames, dropping water over burning forest areas

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With limited fanfare, Basslink resumed operation this week for the first time in almost 6 months. Basslink is Tasmania’s proverbial umbilical cord - a 500 megawatt submarine HVDC cable that connects to the mainland providing both electrical power and data exchange. Its failure back in December last year resulted in an unprecedented energy crisis in the Apple Isle.

To help avert the crisis 200 diesel gensets were installed at a cost of around $44 million. The moth-balled, gas-fired Tamar Valley Power Station was bought back online, and deals were brokered with large industrials to cut back on their energy consumption. Some analysts have estimated the total cost of the crisis at around $400-500 million (see also).

So with Basslink’s resumption the process of repairing the damage begins.

Notwithstanding the immense flood damage, drenching rains in May followed by torrential rains in early June have helped stymie the energy crisis. With HydroTasmania’s smaller catchments now overflowing, many of its run-of-river power stations are operating at more-or-less full capacity. In a matter of a few short weeks Tasmania has gone from acute energy shortage to excess.

Basslink flows for the 4 days period June 13th - 17th. Re-connection occurred on June 13th, around midday. Flows are in megawatts and are positive northwards. Basslink failed on December 20th 2015. Data from AEMO 5-minute dispatch tables.

Meanwhile, the larger hydro catchments such as Gordon have received much needed replenishment. Total storage has doubled over the last six weeks to 27%, increasing at a near record rate of about 2% per week. Storages are now back to levels comparable to mid June in 2014 and 2015.

Tasmanian hydro storage as percentage of total capacity. Data from HydroTasmania. Yellow diamonds show mid-June levels for each year since 2008.

Because of the recent rains and the excess power production, Basslink has this week been flowing northwards into Victoria at an average of about 140 megawatts and, at times, as much as 350 megawatts. That represents about 10% of total Tasmanian dispatch, none of which is being contributed by the emergency 200 diesel generators that were bought in to deal with the crisis, and only a tiny bit from Tamar Valley and Bell Bay gas units.

Meanwhile, elsewhere on the NEM

With mainland wholesale prices now averaging around $90 per megawatt hour, HydroTasmania will be relishing Basslink’s resumption. Now that the rains have come, their prayers will be for those prices to remain high. Such is the crazy brave new world of energy supply, HydroTasmania’s exports are now worth around $2 million a week.

Map of power flows across the 5 state regions in the National electricity map including interchanges for the period 14th-17th June. Note the prices for this period have averaged close to $100 per megawatt hour in volume-weighted terms. Negative values for NETINTERCHANGE imply imports, positive values exports. Data from AEMO’s 5-minute dispatch tables.

However, with mainland prices currently way above what they were even in the Carbon-tax years, questions will be asked. Why they have risen so much? If we factor out the contribution of the carbon tax, prices in New South Wales and Victoria are almost three times what they were in the comparable period two years ago.

Map of power flows across the 5 state regions in the National electricity map including interchanges for the period 16th-19th June, 2014, for comparison with the image above. Note that with the exception of QLD, prices for this period have averaged close to $50 per megawatt hour in volume-weighted terms, about half what they have been in the comparable week, 2016. Note also the 2014 prices include the carbon tax, so in equivalent terms, prices were even lower. Data from AEMO’s 5-minute dispatch tables

Some pundits will no doubt point to recent changes in the South Australian market, following the closure of the Northern Power Station in Port Augusta. However with the national electricity flows mostly converging on New South Wales, the drivers for price setting their would appear much more important.

NSW volume weighted wholesale prices for the 6-week period early May to mid June, 2008 on, shown in red circles. Half hourly prices are shown in small background including the subset for the 6 week period shown in red. Black squares show the carbon tax years adjusted downwards by removing the carbon price (assumed at $20 per megawatt hour). Data from AEMO half hour price and dispatch tables.

And as indicated in the two maps shown above, there have been no obvious changes to the demand and dispatch settings in New South Wales over the last 2 years. So with no obvious reason for such a price spike, it wouldn’t surprise if the regulators were taking a keen interest, not to mention large energy consumers with market exposure.

I doubt HydroTasmania’s latest prayers will be answered in the short-term. At least not until we see some major structural transformation in mainland generation, such as the closure of one or more of the Latrobe Valley brown coal generators. With the Victorian Government this week setting ambitious targets to generate 25% of its electricity from renewable energy by 2020, and 40% by 2025, that may not be very far away. When that happens, HydroTasmania will be hoping its dams are full and Basslink is operational. And by then I hope the Apple Isle has invested more in its exceptional wind resource.

Disclosure

Mike Sandiford receives funding from the Australian Research Council for geological research.

British astronaut Tim Peake is due back to earth six months after blasting off into space.

Recent revelations about the sledgehammering to death of what seem to be Australian cattle in Vietnam provide further evidence of the government’s inability to control how exported livestock are slaughtered overseas.

An Animals Australia investigation reported by ABC’s 7.30 showed what are reportedly Australian cattle being slaughtered in three abattoirs. Australia has suspended trade to the facilities while they are investigated.

The government’s tool to try to ensure humane slaughter is known as the Export Supply Chain Assurance Scheme (ESCAS). This requires cattle to be killed in accordance with World Animal Health Organisation standards. Killing cattle by hitting with a sledgehammer, although common practice in Vietnam, is not allowed by the standards.

The other requirements of ESCAS offer little reassurance to the Australian community that welfare will be safeguarded. Under the standards, cattle must be traced. This means we should know which cattle are Australian, and be able to control and audit the supply chain.

There are problems with this model. Supply-chain control is desirable but potentially contravenes the principles of the World Trade Organisation. Auditing is only as good as the manner in which it is undertaken, and there has been much recent debate about this.

But beyond problems with Australian regulations, there are broader issues with sending live cattle overseas, and to Vietnam in particular.

What do people in Vietnam think about slaughter?

Vietnam is a relatively poor country, and has been even poorer in its recent history. There is little culture of caring for animal welfare when human welfare is the primary concern. Of even greater concern regarding the animals is the fact that Vietnam now acts as a staging post for Australian cattle that are ultimately en route to China and other Asian markets.

In 2015, Australia exported 311,523 cattle to Vietnam, up from 3,353 in 2012. That’s a hundred-fold increase in just three years. Increasingly these exports are of young “feeder” cattle, which need an additional period of feeding before they are ready for slaughter.

At the Centre for Animal Welfare and Ethics (CAWE) at the University of Queensland, we have led a World Animal Health Organisation project to run training courses in Vietnam on livestock slaughter last year. This included research into Vietnamese attitudes to livestock slaughter, in comparison with other Southeast and East Asian countries.

For a forthcoming scientific paper, we surveyed future stakeholders in the industry – veterinary and animal science students. We found that those in Vietnam are more accepting of livestock transport by ship and road than those in China, Malaysia and Thailand. They also more readily agree that exporting livestock from a developed country to developing countries is acceptable.

In another survey, we investigated attitudes of those directly involved in the livestock slaughter and transport industry in Vietnam, Malaysia, Thailand and China. Over 1,000 respondents took part, including 210 from Vietnam.

Similar to respondents from China, Vietnamese respondents were not confident that they could make improvements to the welfare of animals in their care, whereas those from Malaysia and Thailand were. Vietnamese respondents had the least agreement with the survey statement: “In the past I have tried to make improvements to the welfare of the animals in my care.”

In Malaysia, respondents identified religious beliefs as one of the motivations for improving slaughter. For Vietnamese respondents, the main factors were the law, their knowledge, the attitudes of co-workers and company approval.

Vietnamese respondents also rated having the right tools and resources as less important in welfare improvement. This suggests that lack of access to stunning machines isn’t a major factor.

While all respondents thought that welfare improvements would work best when driven by legislation and government, those in Vietnam (and China) also thought that the police played an important role.

Phasing out live export

Our surveys indicate the major differences between the attitudes of the cattle industry in Vietnam and Australia. The police play almost no role in livestock welfare improvement in Australian abattoirs, yet they are considered an important player in Vietnam. Unlike Muslim countries, there is no argument in Vietnam that exports support religious festivals.

By sending young cattle to Vietnam, the Australian agriculture industry is losing out on jobs from growing them to a mature weight and processing them before sending them overseas. There is now a state-of-the-art killing and processing facility in Darwin to achieve this; the first new cattle abattoir to be built in Australia in 50 years.

The latest revelations should act as a signal that Australia should phase out the export of livestock, not immediately, but over five to ten years. This would enable exporters to build trade relations for meat export, delivering a high-quality product to overseas markets for the benefit of Australian producers, the consumers and the Australian conscience.

Clive Phillips is a member of the Voiceless Scientific Expert Advisory Panel, is on the Board of Minding Animals and has recently received funding from Australian and New Zealand governments for provision of training and conducting research on livestock transport and slaughter in SE and E Asia.

Mayors in Queensland’s far north call for council rangers to be able to capture problem crocodiles rather than wait for state wildlife officers to take action

Rogue crocodiles are terrorising communities in Queensland’s far north and Indigenous councils are pleading for greater powers to deal with them before someone is killed.

They want the state government to give their rangers the authority to capture and relocate problem crocodiles from local waterways.

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A massive population of giant spider crabs amasses in waters off the Australian city of Melbourne.

By itself, concrete is a very durable construction material. The magnificent Pantheon in Rome, the world’s largest unreinforced concrete dome, is in excellent condition after nearly 1,900 years. And yet many concrete structures from last century – bridges, highways and buildings – are crumbling. Many concrete structures built this century will be obsolete before its end.

Given the survival of ancient structures, this may seem curious. The critical difference is the modern use of steel reinforcement, known as rebar, concealed within the concrete. Steel is made mainly of iron, and one of iron’s unalterable properties is that it rusts. This ruins the durability of concrete structures in ways that are difficult to detect and costly to repair.

While repair may be justified to preserve the architectural legacy of iconic 20th-century buildings, such as those designed by reinforced concrete users like Frank Lloyd Wright, it is questionable whether this will be affordable or desirable for the vast majority of structures. The writer Robert Courland, in his book Concrete Planet, estimates that repair and rebuilding costs of concrete infrastructure, just in the United States, will be in the trillions of dollars – to be paid by future generations.

Old bridges need new money to replace. Phil's 1stPix/Flickr.com, CC BY-NC

Steel reinforcement was a dramatic innovation of the 19th century. The steel bars add strength, allowing the creation of long, cantilevered structures and thinner, less-supported slabs. It speeds up construction times, because less concrete is required to pour such slabs.

These qualities, pushed by assertive and sometimes duplicitous promotion by the concrete industry in the early 20th century, led to its massive popularity.

Reinforced concrete competes against more durable building technologies, like steel frame or traditional bricks and mortar. Around the world, it has replaced environmentally sensitive, low-carbon options like mud brick and rammed earth – historical practices that may also be more durable.

Early 20th-century engineers thought reinforced concrete structures would last a very long time – perhaps 1,000 years. In reality, their life span is more like 50-100 years, and sometimes less. Building codes and policies generally require buildings to survive for several decades, but deterioration can begin in as little as 10 years.

Many engineers and architects point to the natural affinities between steel and concrete: they have similar thermal expansion characteristics, and concrete’s alkalinity can help to inhibit rust. But there is still a lack of knowledge about their composite qualities – for example, in regard to sun-exposure-related changes in temperature.

The many alternative materials for concrete reinforcement – such as stainless steel, aluminium bronze and fibre-polymer composites – are not yet widely used. The affordability of plain steel reinforcement is attractive to developers. But many planners and developers fail to consider the extended costs of maintenance, repair or replacement.

Cheap and effective, in the short term at least. Luigi Chiesa/Wikimedia Commons, CC BY-SA

There are technologies that can address the problem of steel corrosion, such as cathodic protection, in which the entire structure is connected to a rust-inhibiting electric current. There are also interesting new methods to monitor corrosion, by electrical or acoustic means.

Another option is to treat the concrete with a rust-inhibiting compound, although these can be toxic and inappropriate for buildings. There are several new non-toxic inhibitors, including compounds extracted from bamboo and bacterially derived “biomolecules”.

Fundamentally, however, none of these developments can resolve the inherent problem that putting steel inside concrete ruins its potentially great durability.

The environmental costs of rebuilding

This has serious repercussions for the planet. Concrete is the third-largest contributor to carbon dioxide emissions, after automobiles and coal-fuelled power plants. Cement manufacturing alone is responsible for roughly 5% of global CO₂ emissions. Concrete also makes up the largest proportion of construction and demolition waste, and represents about a third of all landfill waste.

Recycling concrete is difficult and expensive, reduces its strength and may catalyse chemical reactions that speed up decay. The world needs to reduce its concrete production, but this will not be possible without building longer-lasting structures.

Rebar reclamation: an expensive job. Anna Frodesiak/Wikimedia Commons

In a recent paper, I suggest that the widespread acceptance of reinforced concrete may be the expression of a traditional, dominant and ultimately destructive view of matter as inert. But reinforced concrete is not really inert.

Concrete is commonly perceived as a stone-like, monolithic and homogeneous material. In fact, it is a complex mix of cooked limestone, clay-like materials and a wide variety of rock or sandy aggregates. Limestone itself is a sedimentary rock composed of shells and coral, whose formation is influenced by many biological, geological and climatological factors.

This means that concrete structures, for all their stone-like superficial qualities, are actually made of the skeletons of sea creatures ground up with rock. It takes millions upon millions of years for these sea creatures to live, die and form into limestone. This timescale contrasts starkly with the life spans of contemporary buildings.

Steel is often perceived to be inert and resilient too. Terms such as “Iron Age” suggest an ancient durability, although Iron Age artefacts are comparatively rare precisely because they rust. If construction steel is visible, it can be maintained – for instance, when the Sydney Harbour Bridge is repeatedly painted and repainted.

However, when embedded in concrete, steel is hidden but secretly active. Moisture entering through thousands of tiny cracks creates an electrochemical reaction. One end of the rebar becomes an anode and the other a cathode, forming a “battery” that powers the transformation of iron into rust. Rust can expand the rebar up to four times its size, enlarging cracks and forcing the concrete to fracture apart in a process called spalling, more widely known as “concrete cancer”.

Concrete cancer: not pretty. Sarang/Wikimedia Commons

I suggest that we need to change our thinking, to recognise concrete and steel as vibrant and active materials. This is not a case of changing any facts, but rather of re-orientating how we understand and act on those facts. Avoiding waste, pollution and needless rebuilding will require thinking well beyond disciplinary conceptions of time, and this is especially true for the building and construction industries.

The collapsed civilisations of the past show us the consequences of short-term thinking. We should focus on building structures that stand the test of time – lest we end up with hulking, derelict artefacts that are no more fit for their original purpose than the statues of Easter Island.

Guy Keulemans does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.