Welcome to Australia, a land of creatures out to kill you… maybe


Ronelle Welton, University of Melbourne

Welcome to Australia, a place that is the focus of regular reports that nearly every creature is ready and waiting to pounce. If it rains, it brings warnings of venomous snakes. If the weather is dry, then giant spiders can set up house in your power box.

But as Australia prepares once again to welcome many new citizens this Australia Day, it seems appropriate to take a closer look at how deadly our creatures really are.

There is no doubt Australia harbours venomous animals and encounters that can be traumatic and need a rapid emergency response.

We must we careful not to understate the impact of any encounters with venomous animals on families and the sufferers themselves. Nor must we play down the highly specialised management, effective treatment and medical care required.

But is this reputation of a land of deadly and aggressive creatures well founded?

Detail in the data

My colleagues and I recently published a review of hospital admissions and deaths caused by venomous animals in the Internal Medical Journal.

We sourced data from 2001-2013 from national hospital admissions and national coronial information, which showed more than 42,000 hospitalisations from venomous sting or bites. Most – not all – are shown in the graph, below.

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Over the 12 years that’s an average 3,500 people admitted to hospital every year for a venom-related injury. This can be loosely averaged 0.01% of the Australian population per year, or roughly one in 10,000 Australians.

Allergy or anaphylaxis from insect stings such as bees or wasps were responsible for about one-third (33%) of hospital admissions, followed by spider bites (30%) and snake bites (15%).

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Over the 12 years, 64 people were killed by a venomous sting or bite, with more than half of these (34) caused by an allergic reaction to an insect bite that brought on anaphylactic shock.

Of these, 27 deaths were the result of a bee or wasp sting, with only one case of a beekeeper being killed. Anaphylaxis to tick and ant bites combined caused five deaths, the box jellyfish caused three deaths and two deaths were from an unidentified insect.

Given there are 140 species of land snakes in Australia, snake bite fatalities are very rare, at 27 for the study period. To put that in perspective, the World Health Organization estimates that at least 100,000 people die from snake bite globally each year.

The red belly black snake is not as nasty as it looks.
Flickr/Derek A Young, CC BY-NC

While it’s natural to be frightened of snakes, the reality is the number of deaths from snake bites in Australia is very small. In the same time frame, for example, figures from the National Coronial Information System (NCIS) show nearly 5,000 people died from drowning and 1,000 from burns in Australia.

Nevertheless, snake bites do hold the crown as the most common cause of death, with nearly twice as many deaths per hospital admission than any other venomous injury, making snakebite one of the most important issues to address.

Deadly creatures elsewhere

Understandably, living in a country with creatures that can potentially kill us is a daunting prospect. As you can see from the figures, though, they don’t kill as many people as you might think and other countries have their own potentially deadly creatures.

In the United Kingdom there are reports of deaths or injuries from bees, widow spiders, jellyfish and adder snakes.

The continent of America has a menagerie of reptilian assassins such as vipers, and its mammals also pack a punch, with reports of attacks from bears, wolves and mountain lions.

A sturdy Australian would surely quake at the thought of being faced with an offensive grizzly, with no amount of Crocodile Dundee-esk buffalo hypnotism techniques going to get us through that encounter.

Sure Australia also has sharks and crocodiles, but it’s important to note that the majority of our critters do not come after you.

Minimising the minimal risk

Our report, while giving a broad overview of envenoming trends in Australia, does raise more questions than it answers. Questions such as: who is most at risk and how can we support them? Do we need more localised guidelines? And how do we maintain knowledge for such a rare injury?

No one died from a spider bite during the 12 years of our study.
Flickr/Corrie Barklimore, CC BY

This work seeks to initiate new conversations in regard to potential gaps in knowledge in both the public and health domains, and find solutions. We’re currently seeking funding to continue this research.

From an individual or national public health perspective, we can’t make informed decisions until we have a much clearer picture of what’s going on. The big question is how can we manage this coexistence with the creatures around us, without being detrimental to people and the creatures themselves.

It comes down to understanding, appreciating and respecting the amazing diversity nature has provided us. We need to learn about prevention methods and understand correct first aid.

This, together with the ongoing research and improvements in clinical care and the accessibility, affordability, effective management and treatment of bites and stings in Australia, actually make it one of the safest places in the world, and certainly not one of the deadliest.

The Conversation

Ronelle Welton, Scientist at the Australian Venom Research Unit, University of Melbourne

This article was originally published on The Conversation. Read the original article.

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Is ‘clean coal’ power the answer to Australia’s emissions targets?


Lynette Molyneaux, The University of Queensland

As Australia’s energy debate heats up, some politicians are calling for cleaner and more efficient coal power stations to reduce greenhouse gas emissions.

Energy Minister Josh Frydenberg told ABC radio on Tuesday that “ultra-supercritical coal-fired power plants actually drive down the carbon footprint by up to 40%”.

And last week Resources Minister Matt Canavan referenced a report, as yet not released by the Department of Industry, Innovation and Science, which claims that Australia can meet its carbon emission targets by replacing existing coal generators with ultra-supercritical coal generation.

So, is this a reasonable strategy to reduce Australia’s emissions?

Cleaner coal

Australia’s coal generation fleet is ageing and needs replacing. Two-thirds of the 25 gigawatts in operation (after Victoria’s Hazelwood power station is retired this year) is more than 30 years old, according to ACIL Allen’s generator report. By 2025 a further 18% of the fleet will be more than 30 years old.

That means that in 2025 a mere 4GW of our existing coal power will still be considered adequately efficient. This is important because efficient generation affects not only how much generators are paying for fuel, but also carbon dioxide (CO₂) emissions.

Modern coal power plants feed pulverised coal into a boiler to combust. Tubes in the boiler walls then absorb the heat and the steam generated in these boiler tubes turns the steam turbine and generates electricity.

The difference between subcritical, supercritical and ultra-supercritical boilers is in the steam conditions created in the boiler. Supercritical and ultra-supercritical boilers are often referred to as high-efficiency, low-emissions technologies.

Ultra-supercritical power stations are designed to operate at higher steam temperature and pressure. This improves efficiency, and has been made possible by new materials that can cope with higher temperatures.

Ultra-supercritical coal power stations operate under steam conditions above 593-621℃ and 28.4 million pascals (a measure of pressure). You can find further detail in this report.

Using higher temperatures means greater efficiency, producing more electricity using less coal. Australia’s most efficient coal power station, Kogan Creek, is able to convert 37.5% of the gross energy, or calorific value, of coal into electricity. Hazelwood converts only 22%. The remaining energy is lost as heat.

By comparison, ultra-supercritical coal stations are able to convert up to 45% of the gross energy of coal to electricity.

Advanced ultra-supercritical coal generation is expected to convert over 50% of the gross energy of coal to electricity, but the expensive alloys required to accommodate the very high temperature requirements make the plants very expensive. Before advanced ultra-supercritical coal plants can be deployed, new design changes like this will first need to be tested and evaluated in pilot implementations.

Reducing fuel use reduces emissions. Hazelwood’s reported CO₂ emission intensity from 2014-15 was 1,400kg of greenhouse gas for every megawatt-hour of electricity it produced. Kogan Creek emitted 831kg per megawatt-hour.

The greater efficiency of ultra-supercritical generators can reduce emissions intensity to 760kg per megawatt-hour for black coal. Advanced ultra-supercritical generators can reduce emissions even further. Upgrading or replacing Victoria’s brown coal generators to ultra-supercritical would reduce emissions intensity to 928kg per megawatt-hour.

So greenhouse gas emissions can be reduced if ultra-supercritical generators replaced Australia’s old, inefficient coal generators.

But is it enough?

The problem is just how much CO₂ emissions can be reduced. Emissions from coal power are the largest contributors to Australia’s total emissions.

In 2013-4, coal generators emitted 151 million tonnes of greenhouse gas, generating 154 million kilowatt-hours of electricity. Details can be found here. This is 29% of Australia’s total emissions in 2013-14 of around 523 million tonnes. (Transport contributed around 18% to total emissions.)

Let’s assume the current fleet of power stations is operating at 80% capacity, considered to be an economic optimum for coal power. This would generate 176 gigawatt-hours of electricity and 165 million tonnes of emissions. This allows for a 14% increase in consumption of electricity by 2030, which is likely given projections of population and economic growth.

If we then replace the entire 25GW, both black and brown, with ultra-supercritical generation, according to the assumptions included in the Australian Power Generation Technology Report, emissions would total 139 million tonnes. This would represent a 16% reduction in coal emissions, but a mere 5% reduction in Australia’s total emissions in 2013-4.

And then we would have those ultra-supercritical power stations for the next 30-40 years, incapable of reducing our emissions further as global targets tighten.

If Australia were to wait until advanced ultra-supercritical coal power is tested and trialled, then we could speculate that emissions from coal generation could reduce by a further 10% to 124 million tonnes. This would be a more promising 25% reduction in coal emissions, but still only a 7.7% reduction in Australia’s total emissions.

Understanding Australia’s emission reduction target

Australia’s emission reduction target for 2030 is 26-28% below 2005 levels.

Emissions in 2005 were 594 million tonnes. Australia’s climate target would require emissions to reach around 434 million tonnes in 2030, a reduction of 160 million tonnes.

If coal power stations were to reduce emissions by 26-40 million tonnes through a shift to ultra-supercritical generators, then Australia would still be a very long way from meeting its committed targets.

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The only way shifting to ultra-supercritical coal power could meet Australia’s 26-28% climate target is if carbon capture and storage (CCS) were applied.

Ultra-supercritical coal plants are expected to generate electricity at A$80 per megawatt-hour, according to the Australian Power Generation Technology Report. This is 45% more expensive than the average wholesale cost of electricity for 2015-16. If CCS is added, then the projected cost swells to A$155 per megawatt-hour, nearly three times last year’s wholesale cost of electricity.

These costs eventually get passed on to electricity bills, and it’s unlikely that consumers will be willing to see electricity prices rise that much.

Until we see more detail underpinning the current enthusiasm for “clean coal”, we’ll have to speculate on the assumptions of the report referenced by minister Canavan.

The Conversation

Lynette Molyneaux, Researcher, Energy Economics and Management Group, Global Change Institute, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Changing climate has stalled Australian wheat yields: study


Zvi Hochman, CSIRO; David L. Gobbett, CSIRO, and Heidi Horan, CSIRO

Australia’s wheat yields more than trebled during the first 90 years of the 20th century but have stalled since 1990. In research published today in Global Change Biology, we show that rising temperatures and reduced rainfall, in line with global climate change, are responsible for the shortfall.

This is a major concern for wheat farmers, the Australian economy and global food security as the climate continues to change. The wheat industry is typically worth more than A$5 billion per year – Australia’s most valuable crop. Globally, food production needs to increase by at least 60% by 2050, and Australia is one of the world’s biggest wheat exporters.

There is some good news, though. So far, despite poorer conditions for growing wheat, farmers have managed to improve farming practices and at least stabilise yields. The question is how long they can continue to do so.

Worsening weather

While wheat yields have been largely the same over the 26 years from 1990 to 2015, potential yields have declined by 27% since 1990, from 4.4 tonnes per hectare to 3.2 tonnes per hectare.

Potential yields are the limit on what a wheat field can produce. This is determined by weather, soil type, the genetic potential of the best adapted wheat varieties and sustainable best practice. Farmers’ actual yields are further restricted by economic considerations, attitude to risk, knowledge and other socio-economic factors.

While yield potential has declined overall, the trend has not been evenly distributed. While some areas have not suffered any decline, others have declined by up to 100kg per hectare each year.

We found this decline in yield potential by investigating 50 high-quality weather stations located throughout Australia’s wheat-growing areas.

Analysis of the weather data revealed that, on average, the amount of rain falling on growing crops declined by 2.8mm per season, or 28% over 26 years, while maximum daily temperatures increased by an average of 1.05℃.

To calculate the impact of these climate trends on potential wheat yields we applied a crop simulation model, APSIM, which has been thoroughly validated against field experiments in Australia, to the 50 weather stations.

Climate variability or climate change?

There is strong evidence globally that increasing greenhouse gases are causing rises in temperature.

Recent studies have also attributed observed rainfall trends in our study region to anthropogenic climate change.

Statistically, the chance of observing the decline in yield potential over 50 weather stations and 26 years through random variability is less than one in 100 billion.

We can also separate the individual impacts of rainfall decline, temperature rise and more CO₂ in the atmosphere (all else being equal, rising atmospheric CO₂ means more plant growth).

First, we statistically removed the rising temperature trends from the daily temperature records and re-ran the simulations. This showed that lower rainfall accounted for 83% of the decline in yield potential, while temperature rise alone was responsible for 17% of the decline.

Next we re-ran our simulations with climate records, keeping CO₂ at 1990 levels. The CO₂ enrichment effect, whereby crop growth benefits from higher atmospheric CO₂ levels, prevented a further 4% decline relative to 1990 yields.

So the rising CO₂ levels provided a small benefit compared to the combined impact of rainfall and temperature trends.

Closing the yield gap

Why then have actual yields remained steady when yield potential has declined by 27%? Here it is important to understand the concept of yield gaps, the difference between potential yields and farmers’ actual yields.

An earlier study showed that between 1996 and 2010 Australia’s wheat growers achieved 49% of their yield potential – so there was a 51% “yield gap” between what the fields could potentially produce and what farmers actually harvested.

Averaged out over a number of seasons, Australia’s most productive farmers achieve about 80% of their yield potential. Globally, this is considered to be the ceiling for many crops.

Wheat farmers are closing the yield gap. From harvesting 38% of potential yields in 1990 this increased to 55% by 2015. This is why, despite the decrease in yield potential, actual yields have been stable.

Impressively, wheat growers have adopted advances in technology and adapted them to their needs. They have adopted improved varieties as well as improved practices, including reduced cultivation (or “tillage”) of their land, controlled traffic to reduce soil compaction, integrated weed management and seasonally targeted fertiliser use. This has enabled them to keep pace with an increasingly challenging climate.

What about the future?

Let’s assume that the climate trend observed over the past 26 years continues at the same rate during the next 26 years, and that farmers continue to close the yield gap so that all farmers reach 80% of yield potential.

If this happens, we calculate that the national wheat yield will fall from the recent average of 1.74 tonnes per hectare to 1.55 tonnes per hectare in 2041. Such a future would be challenging for wheat producers, especially in more marginal areas with higher rates of decline in yield potential.

While total wheat production and therefore exports under this scenario will decrease, Australia can continue to contribute to future global food security through its agricultural research and development.

The Conversation

Zvi Hochman, Senior Principal Research Scientist, Farming Systems, CSIRO; David L. Gobbett, Spatial data analyst, CSIRO, and Heidi Horan, Cropping Systems Modeller, CSIRO

This article was originally published on The Conversation. Read the original article.

Things fall apart: why do the ecosystems we depend on collapse?


David Lindenmayer, Australian National University

People collapse, buildings collapse, economies collapse and even entire human civilizations collapse. Collapse is also common in the natural world – animal populations and ecosystems collapse. These collapses have the greatest impact on us when they affect resources our industries depend on, leaving ecosystems in tatters and sometimes ruining local economies.

In a new paper, I look at two natural resource industries – fisheries and forestry – that are highly susceptible to collapse.

From the infamous 1980s collapse of the Canadian cod industry to the apparent imminent collapse of the Heyfield sawmill in southern Victoria, we can see a recurring pattern. And by getting better at predicting this pattern, we might be able to avoid collapse in the future.

The stages of collapse

In fisheries, collapse follows a familiar pathway, which has up to eight stages. In a 1993 report for the US Marine Mammal Commission on harvesting ocean resources, L.M. Talbot described these stages:

  1. fishers discover a new fishery, or a new method of harvesting an existing stock

  2. fishers develop the new resource with little or no regulation

  3. major fishing effort results in over-capitalisation of the equipment used to harvest the resource – the value of the fishery can sometimes even be less than the investment fishers made

  4. fishers develop the capacity to catch more fish than the fishery can sustain

  5. fishery becomes depleted and the number of fish caught begins to decline

  6. fishers intensify their efforts to catch fish to offset the decline in harvest

  7. intensive fishing continues as fishers attempt to recoup investments in over-capitalised equipment

  8. fishery is depleted to such levels that it is no longer economic for fishers to go fishing. At this stage the fishery is fully collapsed.

In some cases, regulators attempt to manage the fishery as fishers intensify their efforts. Examples include putting in place quotas and economic subsidies, or reducing the fishing capacity of the fleets.

However, these are often belated and ineffective. This is particularly so given uncertainty about the fishing resource, lack of information on the ecology of the target species, and the fact that an industry with vested interests will lobby hard to protect those interests.

Subsidies at these stages – such as tax breaks and/or fuel rebates – may mean that fishing becomes artificially profitable. Fishers may remain in the industry and continue to overinvest to obtain a greater share of a dwindling resource.

Many forestry industries around the world show similar stages.

Native forest harvesting in Australia is a highly capital-intensive industry. It uses heavy machinery that costs a lot to purchase, leading to high interest repayments. Such efficient harvesting may not only employ relatively few people, but also outstrip the amount of timber that can be sustainably harvested (like stage four in fisheries collapse).

Significant amounts of timber and pulpwood need to be processed continuously to pay the interest and other bills for equipment (stage seven).

Moreover, logging may continue even though it is highly uneconomic to do so (stage eight) and other industries that are damaged by logging (such as the water and tourism industries) are significantly more economically lucrative.

Why do industries overharvest?

Fisheries and forestry often allocate greater harvest limits than the ecosystem can produce without declining.

One key reason this happens is that fish or timber allocations often don’t account for losses from natural events.

For example, the mountain ash forests of Victoria rely on severe wildfires to regenerate. They are also extensively logged for paper and timber production.

Yet the organisation responsible for scheduling of logging in these forests (VicForests) does not account for losses due to fire when calculating how much timber can be harvested. Major fires in 2009 badly damaged more than 52,000 hectares of this forest. But environmental accounting analyses indicate there has been relatively little change in sustained yield allocation since these fires.

Yet, modelling suggests that, over 80 years, wildfire will damage 45% of the forest estate. This amount should therefore should not be included as timber available for logging.

Another driver of the problem of resource over-commitment can be gaming, where stock availability and direct employment are deliberately overstated. This may be to secure the status and influence of a given institution with government, or for other reasons such as leverage in negotiations over access to resources.

The autobiography of Julia Gillard, the former Australian prime minister, suggests this occurred during debates over the fate of forests in Tasmania, alleging that Forestry Tasmania overstated forest available for harvest. Forestry Tasmania denied these allegations.

What can we do?

Early intervention in fisheries and forestry industries can prevent ecosystem and industry collapse. We also need to better ways to assess resources, including accounting for losses of resources due to natural disturbances.

However, in some cases resources have been so heavily over-committed that industry collapse is virtually inevitable. For example, environmental accounting work in the wet forests of the Central Highlands of Victoria suggests very little sawlog resource is left as a result of many decades of overcutting and associated wildfire. Clearfell logging makes these forests more prone to particularly severe fires.

The collapse of the sawlog industry is highly likely, even if there is no fire. This is clear from the pleas from sawmills for access to further forest resources – even when such extra resources basically do not exist.

Now the industry needs to transition to plantations for paper production and for timber (82% of all sawn timber already comes from plantations in the state).

Alternative industries like tourism that employ far more people and contribute more to the economy must be fostered. There are many examples to draw on – New Zealand is one of many.

When governments know in advance about likely industry collapse, then it is incumbent upon them to intervene earlier and help foster transitions to new (and often more lucrative) industries. This ensures that workers can find jobs in new sectors, and the transition is less painful for the community and less costly for taxpayers. Failure to do this is unethical.

The closure of the Hazelwood power station in Victoria is a classic example of a lack of planning for industry transition. The need to close Hazelwood was discussed in formal reports by the former State Electricity Commission more than 25 years ago.

The need to transition the native forest industry to plantations is equally clear and must be done as a matter of urgency.

The Conversation

David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University

This article was originally published on The Conversation. Read the original article.

President Trump threatens to undermine key measure of climate policy success


David Hodgkinson, University of Western Australia

One of the key measures President Barack Obama used to develop climate policy could be under threat under President Donald Trump. The “social cost of carbon”, a dollar measure of how much damage is inflicted by a tonne of carbon dioxide, underpins many US and other energy-related regulations (and in the UK too, for example).

The latest estimates from William Nordhaus, one of the best-known economists dealing with climate change issues (together with Nicholas Stern), put the social cost of carbon in 2015 at a baseline of US$31.20. This rises over time as the impacts of climate change worsen.

Conversely, the social cost of carbon is also the “government’s best estimate of how much society gains over the long haul” by reducing CO₂ emissions.

Nordhaus uses an economic model known as the Dynamic Integrated Climate-Economy (or DICE) model, which he developed in the 1990s. I understand it’s one of the leading models for examining the effects of climate change on the economy. Other researchers have adapted and modified DICE to examine issues associated with the economics of climate change.

Social costs of carbon estimates have been – and remain – helpful for assessing the climate impacts of carbon dioxide emission changes, but perhaps not for the incoming Trump administration in the US.

‘More bad news than good news’

First, though, let’s consider the update to Nordhaus’ DICE model. He finds that the results strengthen earlier ones, which indicate “the high likelihood of rapid warming and major damages if policies continue along the unrestrained path” – his view of current policy settings. He revises upwards his estimate of the social cost of carbon by about 50% on the last modelling.

Further, Nordhaus argues that the 2°C “safe” limit set under the Paris Agreement seems to be “infeasible” even with reasonably accessible technologies. This is because of the inertia of the climate system, rapid projected economic growth in the near term, and revisions to the model.

His view is that a 2.5°C limit is “technically feasible” but that “extreme virtually universal global policy measures” would be required. By implication, such measures could refer to geo-engineering and, in particular, removing CO₂ from the atmosphere.

Nordhaus also notes:

Of the six largest countries or regions, only the EU has implemented national climate policies, and the policies of the EU today are very modest. Moreover, from the perspective of political economy in different countries as of December 2016, the prospects of strong policy measures appear to be dimming rather than brightening.

As a result of the DICE modelling, Nordhaus states that there is more bad news than good news and that the need for effective climate change policies is “more and not less pressing”.

His results relate to a world without climate policies, which, as he says, “is reasonably accurate for virtually the entire globe today. The results show rapidly rising accumulation of CO₂, temperatures changes, and damages.”

An end to the use of the social cost of carbon?

As well as the definition earlier of that cost, it could also be described as a government’s best estimate “of how much society gains over the long haul by cutting each tonne” of CO₂ emissions.

While the Obama administration relied on the DICE model (and others) in arriving at a social cost of carbon – such cost is already important in the formation of 79 federal regulations – it appears that the incoming Trump administration might modify or end this use.

It has been argued – by Harvard’s Cass Sunstein and the University of Chicago’s Michael Greenstone – that such action would defy law, science and economics. It is probably unlikely that use of the social cost of carbon would be done away with completely (lowering the operative number might be more likely), although Greenstone and Sunstein do contemplate it.

Sunstein and Greenstone conclude that, without it, federal regulations would have no quantifiable benefits. And that would have implications for emission reductions and assessing progress on dealing with climate change.

And Nordhaus concludes:

The future is highly uncertain for virtually all variables, particularly economic variables such as future emissions, damages, and the social cost of carbon.

That’s definitely the case for climate change policy and action in the US following the election of Donald Trump. For President Trump’s supporters, it appears that “turning back the clock is the most important thing the president-elect can do to help businesses succeed”.

And the president may well do that. He has argued for an increase in coal use and suggested that, under his administration, the US would withdraw from the Paris climate change agreement.

The Conversation

David Hodgkinson, Associate Professor, University of Western Australia

This article was originally published on The Conversation. Read the original article.

2016 crowned hottest year on record: Australia needs to get heat smart


Liz Hanna, Australian National University; Kathryn Bowen, Australian National University, and Mark Howden, Australian National University

It’s official, 2016 set another record for being the world’s hottest. Three international agencies have confirmed today that last year was the hottest on record.

NASA reported that 2016 was 0.99℃ hotter than the 20th-century average, while the US National Oceanographic and Atmospheric Administration (NOAA) called it at 0.94℃. NOAA also calculated that global land temperatures were 1.43℃ higher. The UK Met Office, using its own data, also reported that 2016 is one of the two hottest years on record.

The figures vary slightly, depending on the baseline reference period used.

Heat records don’t linger for long any more. 2016 surpassed the 2015 record, which surpassed the 2014 record. Three record hot years in a row sets yet another record in the 137-year history of modern accurate and standardised meteorological observation.

For Australia, the Bureau of Meteorology described 2016 as a “year of extreme events” and the fourth hottest at 0.87℃ above the 1961-1990 average. The warming trend is clear.

Australia is already on average 8℃ hotter than the average global land temperature, so further warming means our heat risk is far greater than for other industrialised countries.

This dangerous warming trend sends a dire warning, as average warming delivers many more extreme heat events, as we’re currently seeing in Queensland and New South Wales. These are the killers.

As Australia lurches from heatwave to heatwave, the message is clear: extreme heat is the new norm – so Australia needs to get “heat smart”.

Rising extremes

In Australia the number of days per year over 35℃ has increased and extreme temperatures have increased on average at 7% per decade.

Very warm monthly maximum temperatures used to occur around 2% of the time during the period 1951–1980. During 2001–2015, these happened more than 11% of the time.

This trajectory of increased temperature extremes raises questions of how much heat can humans tolerate and still go about their daily business of commuting, managing domestic chores, working and keeping fit.

We can’t just get used to the heat

Air-conditioning and acclimatisation are not the answer. Acclimatisation to heat has an upper limit, beyond which humans need to rest or risk overheating and potential death. And air-conditioning, if not powered by renewable electricity, increases greenhouse gas emissions, feeding into further climate changes.

We have two key tasks ahead. The first is to stop the warming by drastically reducing emissions – the 2015 Paris Agreement was a step along this path. Several studies have shown that Australia can achieve net zero emissions by 2050 and live within its recommended carbon budget, using technologies that exist today, while maintaining economic prosperity.

Our second task is to adapt to the trajectory of increasing frequency of dangerous heat events.

A heat-smart nation

We can prevent heat-related deaths and illnesses through public health mechanisms. Australia enjoys a strong international track record of world-leading public health prevention strategies, such as our campaign against smoking.

We can equally embrace the heat challenge, by adopting initiatives such as a National Climate, Health and Wellbeing Strategy, which has the support of Australia’s health sector. Its recommendations outline a pathway to becoming a heat-smart nation.

At a recent heat-health summit in Melbourne, experts declared Australia must adopt four key public health actions to reduce heatwave deaths.

These are:

• Prevent

• Prepare

• Respond

• Educate.

These fundamental public health strategies are interlinked and operate at the government, health sector, industry and community levels.

Prevention includes reducing greenhouse gas emissions, as well as reducing exposure. The Bureau of Meteorology provides superb heat warnings that allow us to prepare. Global organisations such as the Intergovernmental Panel on Climate Change (IPCC) provide reports that can underpin greater understanding.

The next challenge is for the populace broadly to act on that knowledge. This requires having options to protect ourselves and avoid hazardous heat exposures while commuting, working and at home.

The health sector must also prepare for demand surges. Tragic outcomes will become increasingly common when, for example, ambulance services cannot meet rising demand from a combination of population growth, urbanisation and forecast heat events.

The health sector will need the capacity to mobilise extra resources, and a workforce trained in identifying and managing heat illness. Such training remains limited.

Individuals and workplaces also need to prepare for heatwaves. In a heat-smart nation, we’ll need to reschedule tasks to avoid or limit exposure, including rest periods, and to ensure adequate hydration with cool fluids.

We’ll need to think about housing. Building houses without eaves or space for trees to provide shade forces residents to rely on air-conditioning. In such houses, power failures expose residents to unnecessary heat risks, and many air-con systems struggle when temperatures exceed 40℃.

Urban planners and architects have solutions. There are many options for safe housing design, and the government should consider supporting such schemes.

We’ll need to think about our own health. Active transport, such as walking and cycling, both reduces emissions and improves fitness. Promoting active transport throughout summer requires the provision of shade, rest zones with seats, and watering stations along commuting routes. High cardio-respiratory fitness also boosts heat resilience: a win-win.

Ultimately, Australia has two options: ignore the risks of increasing heat extremes and suffer the consequences, or step up to the challenge and become a heat-smart nation.


This article was co-authored by Clare de Castella Mackay, ANU.

The Conversation

Liz Hanna, Honorary Senior Fellow, Australian National University; Kathryn Bowen, Senior Research Fellow, Australian National University, and Mark Howden, Director, Climate Change Institute, Australian National University

This article was originally published on The Conversation. Read the original article.