Meet ‘Jaws’, the South American horned frog with a big bite


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The South American horned frog packs quite a bite.
Shutterstock/Norjipin Saidi

Marc Emyr Huw Jones, University of Adelaide; A Kristopher Lappin, California State Polytechnic University, Pomona, and Sean Wilcox, University of California, Riverside

South American horned frogs (Ceratophrys) can capture and swallow whole animals up to their own body size, including other frogs, lizards, snakes and rodents. This is possible because they have jaws that can produce an extremely forceful bite.

Just how powerful is the bite was part of our study, published today in Scientific Reports. We found that small horned frogs – with a head width of 45mm – can bite with a force of 30 Newtons (N). That would feel like having three litres of water balanced on the end of your fingernail.

More impressively, the largest horned frogs from Brazil – with a head width of 100mm – are calculated to bite with a force of 500N. That’s like having 51 litres of water balanced on your fingertip.

A bite like this is similar to that of reptiles and mammals with heads of similar size.

Measuring bite force

Bite force was measured using a special device called a force transducer. Unlike most frogs, horned frogs willingly open their mouths and bite objects (or fingers) as a defensive response.

An example bite force trial. Credit to A. Kristopher Lappin.

This makes it easy to place the free ends of the device into the frog’s mouth so that it bites forcefully, and the device measures the amount of applied force. The free ends of the device are covered in leather to protect the animal’s jaws and to provide a naturalistic gripping surface for the teeth.

Our study is the first to measure bite force in frogs. Bite force has been measured in a variety of other animals including sharks, alligators, turtles, lizards, tuatara, bats, hyenas, rodents and worm amphibians. (A full list can be found here.)

Our study is also unusual in that the relationship between size and bite force was measured using multiple measurements from the same individuals from different points during their growth rather than just using a sample of different-sized individuals.

An adult female horned frog (C. ornata).
A Kristopher Lappin, Author provided

Aggressive and voracious

There are other large frogs that prey on vertebrates but horned frogs are arguably the most aggressive and voracious.

In the wild they will sit patiently, partially buried and well hidden, and attempt to ambush anything unfortunate enough to wander in front of them.

If just out of reach, the horned frog may lift one or both rear legs over its head and wiggle its toes to attract the attention of the potential meal. Once the victim is in range, the frog will rapidly lunge forwards with a wide open mouth.

The extremely adhesive tongue sticks to the prey and retracts, pulling the prey into the mouth, and the huge jaws clamp shut with great force to prevent escape.

This mode of predation contrasts with the majority of the more than 6,800 living species of frog that do not hide to avoid detection by prey, have weak jaws, and rely primarily on their tongue to catch small insects.

Because of their voracious appetite and stout shape dominated by a huge mouth, horned frogs are often referred to as Pacman frogs after the popular arcade game.

This, along with their attractive colour patterns, has made them popular as pets. Wild horned frogs tend to be spotted or striped with various greens and browns – effective camouflage – but captive breeding has led to a variety of colour morphs involving bright reds and yellows, with names such as dragon wing, lipstick, leopard, and two-faced.

Anatomy of a horned frog

Associated with the impressive bite forces of horned frogs and their ambush lifestyle are several important anatomical traits. They have a heavily built skull in which many of the connections between individual skull bones fuse together as the animal grows.

Cranium of a Brazilian Horned Frog (Ceratophrys aurita) based on micro X-ray Computed Tomography. Credit to Marc Jones, Joe Groenke, and the Natural History Museum Los Angeles County.

Along the upper jaw is a battery of small but sharp and recurved teeth, and at the front of the lower jaw is a pair of large bony fang-like projections (called odontoids). The sticky tongue of the horned frogs has been compared to pressure-sensitive adhesives and some species have plates of bone within the skin of their back.

The horns in horned frogs are small pointed structures above the eyes. Their prominence varies among species, and they may help to camouflage the frogs by looking like the tips of the leaves on the forest floor where they sit in wait for prey.

Horned frogs are not currently considered endangered but some species are considered near threatened. Like many animals they are suffering a loss of natural habitat. They are also often killed by local people because of false beliefs that they are venomous, and collection for the pet trade may also be significant.

A prehistoric frog with a bigger bite

Bite forces of some ancient frogs may have been even more impressive than those of today’s South American horned frogs.

Beelzebufo ampinga is a large heavily built frog from the Late Cretaceous period of Madagascar with a skull at least 150mm wide.

Like Ceratophrys it has a robust ornamented skull and teeth with a single point (not two points like most amphibians).

Detailed comparisons with the available skeleton suggest that its closest living relatives might be the South American horned frogs. When the relationship between bite force and size in the South American horned frogs is applied to the skull width of Beelzebufo the value obtained is 2,200N. That’s a massive 224 litres of water balanced on a fingertip – more than three times the weight of an average Australian woman.

A bite of this force is comparable to estimates for mammalian predators such as wolves and female lions, and within the realm of bite forces measured for crocodiles and turtles with similar skull widths.

The ConversationFor context, the bite force of an adult human male averages only about 25% that of a large Beelzebufo. With a bite like that, Beelzebufo would have been capable of easily overcoming small or juvenile dinosaurs that shared its environment.

Marc Emyr Huw Jones, ARC Fellow and Lecturer, University of Adelaide; A Kristopher Lappin, Professor of Biological Sciences, California State Polytechnic University, Pomona, and Sean Wilcox, PhD Candidate in Evolution, Ecology, and Organismal Biology, University of California, Riverside

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

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Review of historic stock routes may put rare stretches of native plants and animals at risk


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The travelling stock routes are a precious national resource.
Author provided

Luke S. O’Loughlin, Australian National University; Damian Michael, Australian National University; David Lindenmayer, Australian National University, and Thea O’Loughlin, Charles Sturt University

Since the 19th century, Australian drovers have moved their livestock along networks of stock routes. Often following traditional Indigenous pathways, these corridors and stepping-stones of remnant vegetation cross the heavily cleared wheat and sheep belt in central New South Wales.

The publicly owned Travelling Stock Reserve network of New South Wales is now under government review, which could see the ownership of much of this crown land move into private hands.

But in a study published today in the Australian Journal of Botany we suggest that privatising stock routes may endanger vital woodlands and put vulnerable species at risk.


Read more: How ancient Aboriginal star maps have shaped Australia’s highway network


The review will establish how individual reserves are currently being used. Although originally established for graziers, the patches of bush in the network are now more likely to be used for recreation, cultural tourism, biodiversity conservation, apiary and drought-relief grazing.

This shift away from simply moving livestock has put pressure on the government to seek “value” in the network. The review will consider proposals from individuals and organisations to buy or acquire long-term leases for particular reserves.

It is likely that most proposals to purchase travelling stock reserves would come from existing agricultural operations.

A precious national resource

Travelling stock reserves across New South Wales represent some of the most intact examples of now-endangered temperate grassy woodland ecosystems.

Our research found that changing the status or use of these reserves could seriously impact these endangered woodlands. They criss-cross highly developed agricultural landscapes, which contain very limited amounts of remnant vegetation (areas where the bush is relatively untouched). Travelling stock reserves are therefore crucially important patches of habitat and resources for native plants and animals.

This isn’t the first time a change in ownership of travelling stock reserves has been flagged. Over the last century, as modern transport meant the reserves were used less and less for traditional droving, pressure to release these areas for conventional agriculture has increased.

Historic stock routes are still used for grazing cattle.
Daniel Florance, Author provided

To understand what a change in land tenure might mean to the conservation values of these woodlands, we spent five years monitoring vegetation in stock reserves in comparison to remnant woodlands on private farmland.

We found that travelling stock reserves contained a higher number of native plant species, more native shrubs, and less exotic plants than woodland remnants on private land.

The higher vegetation quality in travelling stock reserves was maintained over the five years, which included both the peak of Australia’s record-breaking Millennium Drought and the heavy rainfall that followed, referred to as the “Big Wet”.

The take-home message was that remnant woodland on public land was typically in better nick than in private hands.

Importantly, other studies have found that this high-quality vegetation is critical for many threatened and vulnerable native animals. For example, eastern yellow robins and black-chinned honeyeaters occur more frequently in places with more shrubs growing below the canopy.

The vulnerable superb parrot also uses travelling stock reserves for habitat.
Damian Michael, Author provided

The contrast we saw between woodlands in travelling stock reserves and private land reflects the different ways they’re typically managed. Travelling stock reserves have a history of periodic low-intensity grazing, mostly by cattle, with long rest periods. Woodland on active farms tend to be more intensively grazed, by sheep and cattle, often without any strategic rest periods.

The stock reserves’ future

The uncertain future of travelling stock reserves casts doubt on the state of biodiversity across New South Wales.

The current review of travelling stock reserves is considering each reserve in isolation. It flies in the face of the belief of many managers, practitioners and researchers that the true value of these reserves is in the integrity of the entire network – that the whole is greater than the sum of its parts.

Travelling stock reserves protect threatened species, allow the movement of wildlife, are seed sources for habitat restoration efforts, and support the ecosystem of adjacent agricultural land. These benefits depend on the quality of the remnant vegetation, which is determined by the grazing regime imposed by who owns and manages the land.

Of course, not all travelling stock reserves are in good condition. Some are subject to high-intensity livestock grazing (for example, under longer-term grazing leases) coupled with a lack of funding to manage and enhance natural values.

Changing the land tenure status of travelling stock reserves risks increasing grazing pressure, which our study suggests would reduce ecosystem quality and decrease their conservation value.

The travelling stock routes are important parts of our ecosystem, our national heritage, and our landscape. They can best be preserved by remaining as public land, so the entire network can be managed sustainably.

This requires adequate funding for the Local Land Services, so they can appropriately manage pest animals, weeds, erosion and illegal firewood harvesting and rubbish dumping.

The ConversationTravelling stock reserves are more than just The Long Paddock – they are important public land, whose ecological value has been maintained under public control. They should continue to be managed for the public good.

Luke S. O’Loughlin, Research fellow, Australian National University; Damian Michael, Ecologist, Australian National University; David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University, and Thea O’Loughlin, Ecologist, Adjunct Researcher, Charles Sturt University

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

Preventing Murray-Darling water theft: a space agency can help Australia manage federal resources


Andrew Dempster, UNSW

This is the first article in the series Australia’s place in space, where we’ll explore the strengths and weaknesses, along with the past, present and the future of Australia’s space presence and activities.


An independent report into allegations of water theft and corruption in the Murray-Darling Basin has recommended fundamental reforms to the system.

Solutions suggested in the report focus on the state of New South Wales, and involve metered pumps and public access to information. Others have proposed a space-based solution: wide application of “random audits” of water meters by an independent monitoring system: satellites.

But what if we went further. Forget the random audits – why not use satellites to monitor everywhere in the Murray-Darling Basin, all the time?

It’s another argument supporting Australia’s need of a space agency.


Read more: Is the Murray Darling Basin plan broken?


Australian solutions to Australian problems

Among the many arguments in favour of Australia having its own space agency, the use of satellites to collect local data to solve local problems is a vital one.

Under the Australian Space Research Program (the ASRP, which ended in 2013), my colleagues and I developed a design for a pair of Synthetic Aperture Radar satellites that would map soil moisture for all of Australia, every 3 days, to a resolution of 10 metres. We called it “Garada”. This system could readily detect overuse of water of the type noted in the Murray Ddarling Basin, as it was occurring.

Our report was delivered to the Space Policy Unit (which later became the Space Coordination Office), and then the idea stopped dead. There was no mechanism within the public sphere to advance the project: it fell into the hole where a space agency should have been.

The Garada satellites are big and expensive, not exactly the low-cost, “Space 2.0”-focused solutions where most of Australia’s opportunities lie (such as small satellites and startup companies).

However, when we did the study, we showed how the satellite system could be viable if it was considered to be infrastructure. We showed that despite a hefty price tag of A$800 million, the satellite would pay for itself if:

  • its data led to an increase of 0.35% in GDP for non irrigated agriculture, or
  • its data led to a decrease of 7% of irrigation infrastructure, or
  • it was able to save 1% of Murray-Darling water flows.

Read more: Ten reasons why Australia urgently needs a space agency


In a practical sense, the space agency, which needn’t have a big budget itself, wouldn’t have to pay for such a satellite; it just needs a seat at the infrastructure table and compare benefit-to-cost ratios with other projects such as roads and railways. In my opinion, one part of the agency’s role, should it exist, is to make sure infrastructure such as this is considered.

Another important thing to acknowledge here is that both the problem and solution here are federal, with multiple states as stakeholders. An agency that functions to solve problems of this type is not consistent with the sort of “go it alone” approach recently put forward by the ACT and South Australia.

Satellites forge ahead

Even without a space agency, recent years have started to see satellites used to solve Australia-specific problems. The NBN “Skymuster” satellites deliver broadband to remote areas where fibre and wireless solutions were impractical. But they were 100% imported – not an Australian solution.

Start-up Fleet in Adelaide has recently received first-round funding to deliver internet of things services to remote areas from a constellation of cubesats. This may have been achieved against the odds without a local ecosystem, but the company’s official stance is “Australia can no longer afford not to have a space agency”. A number of other start-ups are also starting to gain traction.

Australian universities have been successful in launching and operating cubesats in the QB50 constellation, such as our own UNSW-EC0. These are the first Australian-built satellites to be launched in 15 years. My own group has also delivered GPS receivers as payloads on Defence missions Biarri and Buccaneer.

Australia not at the space table

The world’s largest space conference, the International Astronautical Congress is to be held in Adelaide, September 25-29 2017.

When members of the global space community – NASA, the European Space Agency, the Chinese National Space Agency, the UK Space Agency, and others – meet at the congress to make decisions on missions, strategy, collaborations and other global directions in space, Australia will not be at the table, because we do not have a space agency.


Read more: The 50-year old Outer Space Treaty needs adaptation


The more general commercial and scientific implications related to this have been well outlined. What I have tried to highlight here is simply one example of a possible great many: there are local, practical implications linked to failed advancement of an infrastructure project that relies on expertise in space.

Submissions to the Federal Government’s Review of Australia’s Space Industry Capability closed in August, with many in the industry hoping that its report in March 2018 will recommend an Australian space agency.

The ConversationThe benefits can be broader than most Australians realise – we need to imagine better.

Andrew Dempster, Director, Australian Centre for Space Engineering Research; Professor, School of Electrical Engineering and Telecommunications, UNSW

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

A cleanish energy target gets us nowhere



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Alan Pears, RMIT University

It seems that the one certainty about any clean energy target set by the present government is that it will not drive sufficient progress towards a clean, affordable, reliable energy future. At best, it will provide a safety net to ensure that some cleanish energy supply capacity is built.

Future federal governments will have to expand or complement any target set by this government, which is compromised by its need to pander to its rump. So a cleanish energy target will not provide investment certainty for a carbon-emitting power station unless extraordinary guarantees are provided. These would inevitably be challenged in parliament and in the courts.


Read more: Turnbull is pursuing ‘energy certainty’ but what does that actually mean?


Even then, the unstoppable evolution of our energy system would leave an inflexible baseload power station without a market for much of the electricity it could generate. Instead, we must rely on a cluster of other strategies to do the heavy lifting of driving our energy market forward.

The path forward

It’s clear that consumers large and small are increasingly investing “behind the meter” in renewable energy technology, smart management systems, energy efficiency and energy storage. In so doing, they are buying insurance against future uncertainty, capturing financial benefits, and reducing their climate impacts. They are being helped by a wide range of emerging businesses and new business models, and existing energy businesses that want to survive as the energy revolution rolls on.

The Australian Energy Market Operator (AEMO) is providing critically important information on what’s needed to deliver energy objectives. The recently established Energy Security Board will work to make sure that what’s needed is done – in one way or another. Other recommendations from the Finkel Review are also helping to stabilise the electricity situation.

The recent AEMO/ARENA demand response project and various state-level energy efficiency retailer obligation schemes and renewable energy targets are examples of how important energy solutions can be driven outside the formal National Energy Market. They can bypass the snail-paced progress of reforming the NEM.

States will play a key role

State governments are setting their own renewable energy targets, based on the successful ACT government “contracts for difference” approach, discussed below. Victoria has even employed the architect of the ACT scheme, Simon Corbell. Local governments, groups of businesses and communities are developing consortia to invest in clean energy solutions using similar models.

Some see state-level actions as undermining the national approach and increasing uncertainty. I see them as examples of our multi-layered democratic system at work. Failure at one level provokes action at another.

State-level actions also reflect increasing energy diversity, and the increasing focus on distributed energy solutions. States recognise that they carry responsibilities for energy: indeed, the federal government often tries to blame states for energy failures.

There is increasing action at the network, retail and behind-the-meter levels, driven by business and communities. While national coordination is often desirable, mechanisms other than national government leadership can work to complement national action, to the extent it occurs.

Broader application of the ACT financing model

A key tool will be a shift away from the current RET model to the broader use of variations of the ACT’s contract for difference approach. The present RET model means that project developers depend on both the wholesale electricity price and the price of Large Generation Certificates (LGCs) for revenue. These are increasingly volatile and, over the long term, uncertain. In the past we have seen political interference and low RET targets drive “boom and bust” outcomes.

So, under the present RET model, any project developer faces significant risk, which makes financing more difficult and costly.

The ACT contract for difference approach applies a “market” approach by using a reverse auction, in which rival bidders compete to offer the desired service at lowest cost. It then locks in a stable price for the winners over an agreed period of time.

The approach reduces risk for the project developer, which cuts financing costs. It shifts cost risk (and opportunity) to whoever commits to buy the electricity or other service. The downside risk is fairly small when compared with the insurance of a long-term contract and the opportunity to capture savings if wholesale electricity prices increase.

The ACT government has benefited from this scheme as wholesale prices have risen. It also includes other requirements such as the creation of local jobs. This approach can be applied by agents other than governments, such as the consortium set up by the City of Melbourne.

For business and public sector consumers, the prospect of reasonably stable energy prices, with scope to benefit if wholesale prices rise and limited downside risk, is attractive in a time of uncertainty. For project developers, a stable long-term revenue stream improves project viability.

The approach can also potentially be applied to other aspects of energy service provision, such as demand response, grid stabilisation or energy efficiency. It can also be combined with the traditional “power purchase agreement” model, where the buyer of the energy guarantees a fixed price but the project developer carries the risk and opportunity of market price variations. It can also apply to part of a project’s output, to underpin it.

The ConversationWhile sorting out wholesale markets is important, we need to remember that this is just part of the energy bill. Energy waste, network operations, retailing and pricing structures such as high fixed charges must also be addressed. Some useful steps are being taken, but much more work is needed.

Alan Pears, Senior Industry Fellow, RMIT University

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

More than 1,200 scientists urge rethink on Australia’s marine park plans


Jessica Meeuwig, University of Western Australia

The following is a statement from the Ocean Science Council of Australia, an internationally recognised independent group of university-based Australian marine researchers, and signed by 1,286 researchers from 45 countries and jurisdictions, in response to the federal government’s draft marine parks plans.


We, the undersigned scientists, are deeply concerned about the future of the Australian Marine Parks Network and the apparent abandoning of science-based policy by the Australian government.

On July 21, 2017, the Australian government released draft management plans that recommend how the Marine Parks Network should be managed. These plans are deeply flawed from a science perspective.

Of particular concern to scientists is the government’s proposal to significantly reduce high-level or “no-take” protection (Marine National Park Zone IUCN II), replacing it with partial protection (Habitat Protection Zone IUCN IV), the benefits of which are at best modest but more generally have been shown to be inadequate.


Read more: Australia’s new marine parks plan is a case of the emperor’s new clothes.


The 2012 expansion of Australia’s Marine Parks Network was a major step forward in the conservation of marine biodiversity, providing protection to habitats and ecological processes critical to marine life. However, there were flaws in the location of the parks and their planned protection levels, with barely 3% of the continental shelf, the area subject to greatest human use, afforded high-level protection status, and most of that of residual importance to biodiversity.

The government’s 2013 Review of the Australian Marine Parks Network had the potential to address these flaws and strengthen protection. However, the draft management plans have proposed severe reductions in high-level protection of almost 400,000 square kilometres – that is, 46% of the high-level protection in the marine parks established in 2012.

Commercial fishing would be allowed in 80% of the waters within the marine parks, including activities assessed by the government’s own risk assessments as incompatible with conservation. Recreational fishing would occur in 97% of Commonwealth waters up to 100km from the coast, ignoring the evidence documenting the negative impacts of recreational fishing on biodiversity outcomes.

Under the draft plans:

  • The Coral Sea Marine Park, which links the iconic Great Barrier Reef Marine Park to the waters of New Caledonia’s Exclusive Economic Zone (also under consideration for protection), has had its Marine National Park Zones (IUCN II) reduced in area by approximately 53% (see map below)

  • Six of the largest marine parks have had the area of their Marine National Park Zones IUCN II reduced by between 42% and 73%

  • Two marine parks have been entirely stripped of any high-level protection, leaving 16 of the 44 marine parks created in 2012 without any form of Marine National Park IUCN II protection.

Proposed Coral Sea Marine Park zoning, as recommended by independent review (left) and in the new draft plan (right), showing the proposed expansion of partial protection (yellow) vs full protection (green).
From http://www.environment.gov.au/marinereservesreview/reports and https://parksaustralia.gov.au/marine/management/draft-plans/

The replacement of high-level protection with partial protection is not supported by science. The government’s own economic analyses also indicate that such a reduction in protection offers little more than marginal economic benefits to a very small number of commercial fishery licence-holders.

Retrograde step

This retrograde step by Australia’s government is a matter of both national and international significance. Australia has been a world leader in marine conservation for decades, beginning with the establishment of the Great Barrier Reef Marine Park in the 1970s and its expanded protection in 2004.

At a time when oceans are under increasing pressure from overexploitation, climate change, industrialisation, and plastics and other forms of pollution, building resilience through highly protected Marine National Park IUCN II Zones is well supported by decades of science. This research documents how high-level protection conserves biodiversity, enhances fisheries and assists ecosystem recovery, serving as essential reference areas against which areas that are subject to human activity can be compared to assess impact.

The establishment of a strong backbone of high-level protection within Marine National Park Zones throughout Australia’s Exclusive Economic Zone would be a scientifically based contribution to the protection of intact marine ecosystems globally. Such protection is consistent with the move by many countries, including Chile, France, Kiribati, New Zealand, Russia, the UK and US to establish very large no-take marine reserves. In stark contrast, the implementation of the government’s draft management plans would see Australia become the first nation to retreat on ocean protection.

Australia’s oceans are a global asset, spanning tropical, temperate and Antarctic waters. They support six of the seven known species of marine turtles and more than half of the world’s whale and dolphin species. Australia’s oceans are home to more than 20% of the world’s fish species and are a hotspot of marine endemism. By properly protecting them, Australia will be supporting the maintenance of our global ocean heritage.

The finalisation of the Marine Parks Network remains a remarkable opportunity for the Australian government to strengthen the levels of Marine National Park Zone IUCN II protection and to do so on the back of strong evidence. In contrast, implementation of the government’s retrograde draft management plans undermines ocean resilience and would allow damaging activities to proceed in the absence of proof of impact, ignoring the fact that a lack of evidence does not mean a lack of impact. These draft plans deny the science-based evidence.

We encourage the Australian government to increase the number and area of Marine National Park IUCN II Zones, building on the large body of science that supports such decision-making. This means achieving a target of at least 30% of each marine habitat in these zones, which is supported by Australian and international marine scientists and affirmed by the 2014 World Parks Congress in Sydney and the IUCN Members Assembly at the 2016 World Conservation Congress in Hawaii.


The ConversationYou can read a fully referenced version of the science statement here, and see the list of signatories here.

Jessica Meeuwig, Professor & Director, Marine Futures Lab, University of Western Australia

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

Time Off Again


I am currently being assailed by a variety of ailments and illnesses, and it is therefore necessary for me to take some time off to recuperate. I’m hoping this will only be about a week or so, and then be back at it again. There may be the odd post, but nothing much and nothing is certain. Anyhow, have a break from me and we can get back together in just over a week perhaps. Thanks.

Keeping global warming to 1.5 degrees: really hard, but not impossible



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The window for staving off the worst of climate change is wider than we thought, but still pretty narrow.
Tatiana Grozetskaya/Shutterstock.com

Dave Frame, Victoria University of Wellington and H. Damon Matthews, Concordia University

The Paris climate agreement has two aims: “holding the increase in global average temperature to well below 2℃ above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5℃”. The more ambitious of these is not yet out of reach, according to our new research.

Despite previous suggestions that this goal may be a lost cause, our calculations suggest that staying below 1.5℃ looks scientifically feasible, if extremely challenging.


Read more: What is a pre-industrial climate and why does it matter?.


Climate targets such as the 1.5℃ and 2℃ goals have been interpreted in various ways. In practice, however, these targets are probably best seen as focal points for negotiations, providing a common basis for action.

To develop policies capable of hitting these targets, we need to know the size of the “carbon budget” – the total amount of greenhouse emissions consistent with a particular temperature target. Armed with this knowledge, governments can set policies designed to reduce emissions by the corresponding amount.

In a study published in Nature Geoscience, we and our international colleagues present a new estimate of how much carbon budget is left if we want to remain below 1.5℃ of global warming relative to pre-industrial temperatures (bearing in mind that we are already at around 0.9℃ for the present decade).

We calculate that by limiting total CO₂ emissions from the beginning of 2015 to around 880 billion tonnes of CO₂ (240 billion tonnes of carbon), we would give ourselves a two-in-three chance of holding warming to less than 0.6℃ above the present decade. This may sound a lot, but to put it in context, if CO₂ emissions were to continue to increase along current trends, even this new budget would be exhausted in less than 20 years 1.5℃ (see Climate Clock). This budget is consistent with the 1.5℃ goal, given the warming that humans have already caused, and is substantially greater than the budgets previously inferred from the 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), released in 2013-14.

This does not mean that the IPCC got it wrong. Having predated the Paris Agreement, the IPCC report included very little analysis of the 1.5℃ target, which only became a political option during the Paris negotiations themselves. The IPCC did not develop a thorough estimate of carbon budgets consistent with 1.5℃, for the simple reason that nobody had asked them to.

The new study contains a far more comprehensive analysis of the factors that help to determine carbon budgets, such as model-data comparisons, the treatment of non-CO₂ gases, and the issue of the maximum rates at which emissions can feasibly be reduced.

Tough task

The emissions reductions required to stay within this budget remain extremely challenging. CO₂ emissions would need to decline by 4-6% per year for several decades. There are precedents for this, but not happy ones: these kinds of declines have historically been seen in events such as the Great Depression, the years following World War II, and during the collapse of the Soviet Union – and even these episodes were relatively brief.

Yet it would be wrong to conclude that greenhouse emissions can only plummet during times of economic collapse and human misery. Really, there is no historical analogy to show how rapidly human societies can rise to this challenge, because there is also no analogy for the matrix of problems (and opportunities) posed by climate change.

There are several optimistic signs that peak emissions may be near. From 2000 to 2013 global emissions climbed sharply, largely because of China’s rapid development. But global emissions may now have plateaued, and given the problems that China encountered with pollution it is unlikely that other nations will attempt to follow the same path. Rapid reduction in the price of solar and wind energy has also led to substantial increases in renewable energy capacity, which also offers hope for future emissions trajectories.

In fact, we do not really know how fast we can decarbonise an economy while improving human lives, because so far we haven’t tried very hard to find out. Politically, climate change is an “aggregate efforts global public good”, which basically means everyone needs to pull together to be successful.

This is hard. The problem with climate diplomacy (and the reason it took so long to broker a global agreement) is that the incentives for nations to tackle climate change are collectively strong but individually weak.


Read more: Paris climate targets aren’t enough but we can close the gap.


This is, unfortunately, the nature of the problem. But our research suggests that a 1.5℃ world, dismissed in some quarters as a pipe dream, remains physically possible.

Whether it is politically possible depends on the interplay between technology, economics, and politics. For the world to achieve its most ambitious climate aspiration, countries need to set stronger climate pledges for 2030, and then keep making deep emissions cut for decades.

The ConversationNo one is saying it will be easy. But our calculations suggest that it can be done.

Dave Frame, Professor of Climate Change, Victoria University of Wellington and H. Damon Matthews, Professor and Concordia University Research Chair in Climate Science and Sustainability, Concordia University

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