We’ve learned a lot about heatwaves, but we’re still just warming up


Sarah Perkins-Kirkpatrick, UNSW Australia and Christopher J. White, University of Tasmania

The journal Climatic Change has published a special edition of review papers discussing major natural hazards in Australia. This article part of a series looking at those threats in detail.


Australia is no stranger to heatwaves. Each summer, large areas of the continent fry under intense heat for days on end, causing power outages, public transport delays, and severe impacts to human health. The estimated impact on our workforce alone is US$6.2 billon per year. Heatwaves are also Australia’s deadliest natural hazard, accounting for well over half of all natural disaster-related deaths.

Along with our colleagues, we have taken a close look at what we know and don’t know about heatwaves in Australia, as part of a series of reviews produced by the Australian Energy and Waster Exchange initiative.

Let’s start with the stuff we know. First, we are very clear on the weather systems that drive heatwaves in Australia’s densely populated coastal areas. Typically, a persistent high-pressure system sits next to the region experiencing the heatwave, pushing hot air from the centre of Australia towards that region. The location of the high depends on the region experiencing the heatwave, but there is always one there.

These high-pressure systems are created and sustained by other weather influences farther afield, for instance. We know for instance that heatwaves in Melbourne are coupled with tropical cyclones to the northwest of Australia.

Other, longer-term variables can affect not just individual heatwaves but their patterns, timing and severity too. So heatwaves are likely to be much longer and more frequent during El Niño than La Niña phases over much of northern and eastern Australia. However, this does not influence heatwaves over Australia’s far southeast – here, the most important driver is changes to wind patterns over the Southern Ocean.

We also know that heatwave trends have increased in the observational record, and, unfortunately, that they will continue to do so. By far the strongest trend is in the number of heatwave days experienced each season. Over much of eastern Australia, this trend is as large as two extra days per season, per decade.

Trends in seasonal heatwave days, per decade.
Perkins-Kirkpatrick et al., Climatic Change, Author provided

Looking into the future, heatwaves are projected to become more frequent, with increases of between 20 and 40 extra days per season in the north and 5-10 extra days in the south likely by the end of this century, under a “business as usual” scenario. The intensity of heatwaves over southern Australia is also increasing faster than the average temperature. This is not good news for our ageing population, our fragile ecosystems and our outdated infrastructure.

The Australian research community has been successful in leading the development of a comprehensive way to measure marine heatwaves. Just like the atmosphere, areas of the ocean can experience prolonged periods of abnormally warm temperatures. These marine heatwaves can be every bit as damaging as atmospheric ones, decimating marine habitats and killing coral.

What we don’t yet know

Perhaps surprisingly, given the amount of research and public attention that heatwaves attract, they still do not have an official definition. The Bureau of Meteorology uses a concept called excess heat factor, which looks at maximum temperatures and ensuing minimum temperatures over a three-day period, incorporating the key characteristic of heatwaves of heat tending to persist overnight. However, we still do not have a universal definition that fits all situations.

We are also unclear on how the physical mechanisms that drive heatwaves will change under ongoing greenhouse warming. Recent research suggests that background warming will predominantly drive future increases in heatwaves, with some heatwave-inducing systems moving further south. But we don’t really know how future changes to patterns such as El Niño will continue to influence our heatwaves.

We also don’t really understand the extent to which the land surface drives Australian heatwaves. European studies have shown that dry conditions leading up to heatwave season, resulting in more parched soils, are a recipe for more intense and longer events, particularly when coupled with a persistent high-pressure system.

For Australia, we know that dry soil contributed to the deadly heatwave that preceded the Black Saturday bushfires in 2009. But more extensive studies are needed to understand this complex relationship over Australian soil (pun intended).

We also need a more comprehensive understanding of marine heatwaves. So far there has been only a handful of studies describing individual events. We still don’t know how much marine heatwaves have increased over recent decades, or how their causes and severity will change in the future. Given how vulnerable we are to marine heatwaves here in Australia, this topic should be a national research priority.

Finally, we need to develop more practical predictions of how heatwaves are likely to affect people in the future. We know how bad the impacts of heatwaves can be, and we know in general terms how heatwaves will change in the future. Yet the vast majority of our projections come from global climate models. Forecasting the exact impacts calls for finer spatial detail, using regional climate models. But these models are far more computationally expensive to run, and more investment into this area is necessary.

There is no doubt that heatwaves have been, and will continue to be, an integral feature of Australia’s climate, and recent research has taught us a lot about them. But there is more work to be done if we want to safeguard Australians properly from their deadly impacts in the future.

The Conversation

Sarah Perkins-Kirkpatrick, Research Fellow, UNSW Australia and Christopher J. White, Lecturer in Environmental Engineering, University of Tasmania

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

Keeping warming below 1.5℃ is possible – but we can’t rely on removing carbon from the atmosphere


Kate Dooley, University of Melbourne

This week international leaders are meeting in Marrakech to thrash out how to achieve the Paris climate agreement, which came into force on Friday. The Marrakech meeting is the 22nd Congress of Parties (or COP22) to the United Nation’s climate convention. One of the key goals of the agreement is to limit global warming to well below 2℃, and aim to limit warming to 1.5℃.

With global greenhouse gas emissions still rising, this is a daunting task. Numerous models, including recent research, suggest we will not be able to achieve this without removing large amounts of greenhouse gases from the atmosphere later this century (known as “negative emissions”).

But scientists are becoming increasingly sceptical of the concept, as it may create more problems than it solves, or fail to deliver. Instead, we need to ramp up action before 2020, before even the earliest targets of the Paris Agreement.

Going negative

Some models suggest that up to 1 trillion tonnes of carbon dioxide needs to be removed from the atmosphere to meet the 1.5℃ goal.

This idea is increasingly being called out as a risky and “highly speculative” strategy to limit warming to 1.5℃, as it puts food security and biodiversity at risk, and may not even be possible to deliver. The Convention on Biodiversity has also now weighed in on the issue, declaring that carbon removal techniques are highly uncertain.

A recent report from the Stockholm Environment Institute (SEI), summarised here, argues that the scale of negative emissions assumed by many climate models is improbably high.

The key components of negative emissions are reducing deforestation, planting trees, and an untested technology called “bioenergy with carbon capture and storage” or BECCS. The involves burning plant matter to produce energy, capturing the waste CO₂, and then storing it underground. The result is less CO₂ in the atmosphere.

But there are several problems with these strategies. For one, the scale of land required for the expected level of negative emissions suggests serious social and ecological risks, since land plays a crucial role in food security, livelihoods and biodiversity conversation.

Indeed, the scale of bioenergy supply in many cases is equivalent to the current global harvest of all biomass – for food, feed, and fibre – assuming a doubling of human harvest of biomass by 2050.

The SEI paper argues that the risks and uncertainties associated with negative emissions could lock us into much higher levels of warming than intended, substantially undermining society’s overall mitigation efforts.

Better ways to remove carbon

So does all of this mean the 1.5℃ goal is out of reach? Some may think so.

However, the SEI analysis finds that if emissions were cut sufficiently quickly and ambitiously, we wouldn’t need to rely so much on negative emissions. We could also choose negative emissions methods with lower impacts on biodiversity, resource demands, and livelihoods.

The SEI analysis optimistically suggests that a maximum of 370 billion to 480 billion tonnes of CO₂ could be removed without exceeding biophysical, technological and social constraints. This would be done through protecting forests and allowing degraded forests to regenerate, along with some reforestation.

Even that would be extremely challenging to achieve, but done right, for example through community forestry and agro-ecological farming,, climate mitigation and sustainable development could go together.

In fact, securing land rights of indigenous peoples and local communities who protect and preserve the carbon stocks in forests is one of the most cost-effective forms of climate mitigation we have, with obvious social co-benefits.

Scaling up

The real threat of negative emissions is the potential to delay emissions reduction into the future. Many modelled pathways for 1.5℃ that include substantial negative emissions suggest that emissions do not begin to decline until the late 2020s.

But limiting negative emissions to lower levels would require immediate global mitigation on a scale greatly exceeding that which has so far been pledged by nations under the Paris Agreement.

We cannot wait until 2020 to speed up global action on climate change – less action now will mean more work later.

Key for strengthening pre-2020 action in Marrakech will be a facilitative dialogue on enhancing ambition and support and a high level ministerial meeting on increased ambition of 2020 commitments under the Kyoto Protocol.

Many countries, including Australia, still have completely inadequate targets for 2020, making arguments about whether they are on track to meet them or not moot.

The Moroccan government has dubbed Marrakech the “action COP”. Action here must focus on the urgent need for global emissions to begin declining before 2020, and on the finance needed to deliver it. This includes scaling up the rollout of renewable energy, halting and reversing the loss of the world’s forests, and tackling rich world consumption patterns to ensure equitable mitigation pathways.

Limiting global warming to 1.5℃ is not only possible, it is the only chance of survival for the most vulnerable communities around the world, who are increasingly exposed to rising sea levels, drought and food shortages.

As Erik Solheim, head of the UN Environment Program (UNEP), and Jacqueline McGlade, UNEP’s chief scientist, wrote in a recent report, those most vulnerable “take little comfort from agreements to adopt mitigation measures and finance adaptation in the future. They need action today”.

The Conversation

Kate Dooley, PhD candidate, Australian German Climate and Energy College, University of Melbourne

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

Should genetically modified organisms be part of our conservation efforts?


Fern Wickson, GenØk – Centre for Biosafety

Biotechnology is rapidly evolving through developments in genome editing and synthetic biology, giving birth to new forms of life.

This technology has already given us genetically modified (GM) plants that produce bacterial pesticides, GM mosquitos that are sterile and GM mice that develop human cancers.

Now, new biotechnological techniques are promising to deliver a whole host of new lifeforms designed to serve our purposes – pigs with human organs, chickens that lay eggs containing cholesterol controlling drugs, and monkeys that develop autism. The possibilities seem endless.

But do these genetically modified organisms (GMOs) have conservation value?

The biodiversity of life on earth is globally recognised as valuable and in need of protection. This includes not just wild biodiversity but also the biodiversity of agricultural crop plants that humans have developed over thousands of years.

But what about the synthetic forms of biodiversity we are now developing through biotechnologies? Does anyone care about this synbiodiversity?

It’s a question I was compelled to ask while conducting research into the Svalbard Global Seed Vault (SGSV).

A frozen ‘Noah’s Ark’ for seeds

The SGSV is the global apex of agricultural biodiversity conservation, an approach to conservation where collections of diverse seed samples are kept in frozen storage in genebanks for future use by plant breeders.

The SGSV is a frozen cavern in a mountain on the arctic island of Svalbard, halfway between mainland Norway and the North Pole. It has been called a Noah’s Ark for crop plants (also the “doomsday vault”) because it is the place where genebanks from all around the world send backup copies of their seed collections for safe-keeping.

Here the seeds are sealed inside bags sealed inside boxes locked in a freezer locked in a mountain. They are sent there to be kept safe from the threats genebanks can face, such as energy shortages, natural disasters and war.

The Svalbard Global Seed Vault.
Flickr/Landbruks og matdepartementet, CC BY-NC-ND

Seeds in the SGSV can only be accessed by the genebank that deposited them and only one withdrawal has been made so far, by researchers from the International Center for Agricultural Research in the Dry Areas (ICARDA ) seeking to restore their collections after the destruction of Aleppo in war-torn Syria.

The SGSV is managed through a collaborative agreement between the Norwegian government, the Crop Trust and the Nordic Genetic Resource Center (NordGen).

It opened in 2008 and currently houses 870,971 different samples of 5,340 species from 233 countries, deposited by 69 institutes.

Inside the frozen Svalbard Global Seed Vault.
Flickr/Landbruks og matdepartementet, CC BY-NC-ND

Are there any GMOs frozen in the vault?

During my research into the SGSV I asked if it held any GM seeds.

Despite initially receiving conflicting responses, the formal answer was ultimately “no”. But different reasons were given for this and all are open to change.

The vault is not a certified facility for GMO storage

Facilities working with GMOs require certification to do so.

While the SGSV is not currently certified, it could be since requirements typically relate to ensuring strict containment and the SGSV is already oriented towards this goal.

Also, since no analysis of seeds is performed at the SGSV or required for deposits, the collections may actually be unintentionally (and unwittingly) contaminated. This is because a mixing with GM crops could have happened via seed or pollen flow before the material was sent to the vault.

There is no political will to include GM crops

Currently, no one in the SGSV management wants to become (any further) entangled in the controversy surrounding GM crops.

They already face what they see as false conjectures about the role of the biotechnology industry (fuelled no doubt by the fact that organisations involved in the biotechnology industry have donated funds to the Crop Trust).

Several of the depositing genebanks also actively support biotechnology research. Therefore, if they wanted to store GMOs in the future, the will to seek certification may certainly change.

Norway has a strict GMO policy that requires not just evidence of safety but also of social utility and contribution to sustainable development. This means no GM crop has yet been approved for either cultivation or import.

But this is currently being challenged by a government committed to speeding up assessments and advocating for weakened interpretations of the law. This further indicates the potential for political will to change.

GM crops do not meet the requirements for multilateral access

The International Plant Treaty is a crucial foundation for the SGSV. As such, depositing genebanks are required to agree to multilateral access to their collections if they wish to deposit backup copies in the SGSV.

But GM crops are not freely accessible to all as part of the common heritage of humanity. They are patented inventions owned by those claiming to have created them. The SGSV requirement that deposits be available for multilateral access can be waived though.

But if GM crops are not in the SGSV, should they be?

Do GMOs have conservation value?

Very little work has examined the moral status and conservation value of GM crops.

As the fields of genome editing and synthetic biology are now undergoing rapid development though, we have an important opportunity to consider how we relate to biotechnological forms of biodiversity. We can also think about whether it might be possible to navigate through syn- to symbiodiversity.

That is, instead of focusing on these life forms as synthetic human inventions, we could begin to think about them as co-creations of human-nature interactions. In doing so, we may then shift the focus away from how to make synthetic organisms to satisfy our needs and place more emphasis on how to interact with other life forms to establish symbiotic relations of mutual benefit.

The French sociologist of science and anthropologist Bruno Latour has urged us to love our monsters, to take responsibility for our technologies and care for them as our children.

Certainly it seems fair to argue that if we don’t care for our biotechnological co-creations with a sense of (parental) responsibility, perhaps we shouldn’t be bringing them to life.

How do we care for GM crops?

The model of freezing seeds in genebanks and backing up those collections at the SGSV is one way to conserve biodiversity. Another, however, is the approach of continuing to cultivate them in our agricultural landscapes.

While this model of conservation has generated and maintained the biodiversity of traditional crop varieties for thousands of years, there is now a significant shift taking place. More than 90% of traditional crop varieties have now disappeared from our fields and been replaced by genetically uniform modern varieties cultivated in large-scale monocultures. Meaning, there may be no GM crops frozen in the SGSV, but there are plenty in the ground.

So this leaves me questioning what it is we really cherish? Are we using our precious agricultural resources to expand the diversity of humanity’s common heritage?

Or are we rather placing our common heritage on ice while we expand the ecological space occupied by privately owned inventions? And who cares about synbiodiversity anyway?

The Conversation

Fern Wickson, Senior Scientist & Program Coordinator, GenØk – Centre for Biosafety

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