Recording date:

What was Australia’s climate like before official weather records began? How do scientists use tree-rings, ice cores and tropical corals to retrace the past? What do Indigenous seasonal calendars reveal? And what do settler diaries tell us about natural climate cycles through their mention of rainfall, drought, bushfire and snowfall?

Dr Joëlle Gergis, award-winning climate scientist and writer from the University of Melbourne, discusses her new book Sunburnt Country, which pieces together Australia’s climate history for the first time and uncovers a continent long vulnerable to climate extremes and variability. It shows how human activities have altered patterns that have been with us for millions of years. Sunburnt Countryhighlights the impact of a warming planet on Australian lifestyles and ecosystems, and the power we all have to shape future life on earth.

In association with Melbourne University Publishing.

Speakers: Marie-Louise Ayres (M), Joelle Gergis (J)

Audience: (A)

Location: National Library of Australia   

Date: 12 April 2018

M:        Friends, ladies and gentlemen, welcome to the National Library of Australia, I’m Marie-Louise Ayres and it’s my privilege to be the Director General of the National Library of Australia as we celebrate 50 years in this beautiful building.

As we begin I would like to acknowledge the traditional custodians of this land, I thank their elders past and present for caring for the land we are now privileged to call home. And in terms of the topic of our lecture tonight have been reflecting on the tens of thousands of years of climate change that people in this area would have seen.

We’re delighted to welcome Dr Joelle Gergis to the Library again. Joelle was a paleoclimatologist from the University of Melbourne and an Australian Research Council research fellow. Joelle has been a frequent visitor to the Library over 10 years maybe? As a leading ARC researcher on the Search project, a landmark Australian research project that drew together a team of scientists from the CSIRO, the Bureau of Meteorology, the Murray Darling Basin Authority and the Victorian Department of Environment and Sustainability together of course with the State and National Libraries and environmental historians to extend our documentary record of natural climate variability in the Australian region. By analysing historical records such as settler diary entries and indigenous seasonal calendars Joelle and her team have contributed a significant new perspective to the history of climate and climate change in Australia.

In 2014 this research resulted in her ARC research team receiving the prestigious Eureka Prize for Excellence in Interdisciplinary Scientific Research otherwise known as the Oscars of Australian science. The research has also resulted in Joelle’s ground-breaking new book, Sunburnt Country, The Future and History of Climate Change in Australia.

We’re very excited to be hearing about this book tonight here in the Library given that quite a lot of the research for it actually was done here. So please join me in welcoming Joelle. Thank you.

Applause

J:          Well good evening, everyone, it’s my great pleasure to be here at the National Library to share my new book with you.

This is the story of my 10-year quest to join the dots between the things we now understand about natural climate variability and human-caused climate change here in Australia. Sunburnt Country pieces together our national story about climate change for the first time in the hope that it starts an important conversation that we need to have as Australians.

I know it’s easy to let the facts and figures wash over you when we talk about climate change but in this book I’ve tried to make it very clear how it is threatening the things we care about the most. And tonight is also an invitation for you to allow yourself the permission to connect your head and your heart, to really imagine what climate change means for you and for our collective future.

Many people here in the room would be very familiar with Dorothea Mackellar’s poem, My Country. The second stanza is one of the most iconic pieces of Australian poetry. It reads I love a sunburnt country, a land of sweeping plains, of ragged mountain ranges, of droughts and flooding rains. I love her far horizons, I love her jewelled sea, her beauty and her terror, the wide brown land for me. And this was actually inspired after witnessing the breaking of the federation drought in 1904 on their family’s property in the Hunter Valley region of New South Wales.

And this poem is regarded by many Australians as a universal statement of our national connection to the land because it captures this quintessential character of Australian climate variability and extremes. So everyone in the room knows that Australia has water and climate extremes that are just a part of Australian life. We’re subjected to droughts and flooding rains, to bushfires, to dust storms, cyclones. We’re a nation that’s very vulnerable to weather and climate extremes.

And the Bureau of Meteorology’s official records begin in 1900 which while it’s the best records that we have it doesn’t give us a complete view of the range of natural climate variability that we can experience and I wanted to know what happened before 1900. And in 2009 I was awarded an Australian Research Council Linkage grant to look at the long-term history of Australian climate variability and extremes. The project was known as the South-Eastern Australian Recent Climate History project and as Marie-Louise said we partnered with 10 organisations including the Bureau of Meteorology, the National and the State Libraries of Sydney, Melbourne and Canberra, the Murray Darling Basin Authority, Melbourne Water and a range of other organisations. And it was actually the largest ARC Linkage grant awarded in the Faculty of Science at the University of Melbourne at the time, it was bigger than Ben Hur is what we used to say.

And it turns out that historical records reveal a fascinating history of our nation’s climatic past. And our task was to gather up as many data sources as possible to reconstruct our climate history to get a sense of how unusual recent extremes are in a longer-term historical context.

And so the central question was what can we learn about our climate from studying the past? And many people don’t realise that an enormous amount of weather and climate information is found within historical records so things like early settler accounts, colonial diaries, government correspondence, weather diaries, ship log books, early newspapers, farm records and even explorer records. And as scientists we rarely find ourselves delving into the very rich historical collections of our State and National Libraries and archives. But when we did we came across an incredibly diverse array of material that contained invaluable weather and climate information that could be used to reconstruct our climate history.

And to our surprise we found that the very earliest colonial documents contained weather information so along with things like which transports were hired to carry convicts to Botany Bay it was also information usually tucked up the back about weather. And so I wanted to give you a taste of the first documented account of Australian drought that we came across in 1790 to 1791. February 1791, the heat was so excessive that immense numbers of the large fox bat were seen dropping into the water. Many dropped dead while on the [wind] 6:59. In several parts of the harbour the ground was covered with different sorts of small birds, some dead and others gasping for water. From the numbers which fell into the brook at Rose Hill the water was tainted for several days. It was supposed that more than 20,000 of them were seen within the space of a mile.

So this really evocative description is really describing the heat stress on local wildlife. And we know that mass mortality of flying foxes is known to occur when temperatures exceed about 42 degrees Celsius. And some of you might remember the Black Saturday bushfires where 5,000 flying foxes actually died on the Yarra Bend in Melbourne. And these dry conditions continued in winter where the ground was described as so dry, hard and literally burnt up that it was almost impossible to break it with a hoe and until this time there had been no hope or probability of the grain vegetating. So again this gave us a really interesting insight into the beginning of Australian agriculture which is something you can’t really get when you're looking at quantitative weather records so it was really valuable.

So what we did is we collated as many historical records as possible to try and reconstruct Australian climate history back to 1788 as part of this Search project. And it’s the first time it had been attempted in such a comprehensive way. And it revealed new periods of droughts and floods that were previously either unknown or very poorly described. And it also allowed us to look at the impacts of past extremes and think about our vulnerability to natural disasters.

And while what we uncovered in the historical documents was really fascinating but being scientists we wanted to cross-check our results with early weather records to see how well these narrative accounts lined up with the quantitative weather observations that we could find. And in 2008 I stumbled across Australia’s oldest weather record kept by William Dawes from 1788 to 1791. The original’s actually held in the Royal Society of London which I tracked down in 2009 but a microfilm was actually held at the University of Melbourne’s Baillieu Library. And it was one of a handful of weather records with such fine detail for that period of the southern hemisphere that covers the late 18th century. There are daily temperature, air pressure – it was daily temperature readings, air pressure, wind conditions and remarks recorded four to six times a day.

And this record was left untouched for 220 years until I analysed the record in 2008. And the results lined up remarkably well with those narrative accounts I was just mentioning and so I published the work to try and highlight the potential of historical records in understanding contemporary climate variability and climate change. This was sort of like a proof of concept to show that this can actually work and it’s really valuable.

I also came across another gem of a record quite early on and it was a ship log that was kept by William Bradley and he was aboard The Sirius which was the flagship of the first fleet and he took daily noon temperatures and air pressure as they journeyed on their eight-month voyage on the first fleet from England to Australia in 1787 to 1788. And so each of those red dots represents a time where he took a measurement of temperature and air pressure and while – when they got to the Australian coastline they describe seeing snow as they rounded Tasmania in the height of summer in January 1788, very cold and wet conditions, sails ripping in howling winds and convicts on their knees and prayers.

And one of the surgeons aboard one of the ships said it blew a perfect hurricane, I never before saw a sea in such a rage. So they were really starting to get a taste of Australian climate. And along with the historical documents we sometimes came across the incredibly beautiful artworks that are held in places like the National Library like this watercolour painting of a flood on the Hawkesbury River. And our project partners from the National Library and also the State Library in New South Wales and State Library in Victoria sent many images and early photographs our way which we were very grateful for.

And it was an opportunity to discover the stories behind these images or bring to life the conditions described in the historical record. So for example the great flood of March 1806 on the Hawkesbury River destroyed property, farms and livestock. According to the newspaper reports of the time many people lost everything that they possessed. And such extensive crop losses in the colony’s food bowl reduced it to a state little short of starvation. Food was severely rationed and no flour was allowed for the use of the baking of biscuits and cakes which seemed to annoy some people in the documents. Like the modern-day SES service rescue operations in the early 1800s were coordinated by volunteers dedicating to helping their local communities and hundreds of people were rescued from rooftops or rafts flowing in the floodwaters by row boat which is really what this image is showing.

But of course humans had been in Australia long before Europeans arrived and the first Australians have followed intricate cycles of flowering plants and animal cues for well over 40,000 years. Knowledge is passed down from generation to generation through stories. And an intimate knowledge of the environment was really a matter of life or death. It was used for practical purposes like tracking hunting grounds or identifying safe travelling routes as the seasons began to shift. And this oral history is shared by elders with their children as they grow up experiencing their local country.

And the Bureau of Metrology have done a bit of work working with local communities to try and gather up these stories to try and record them. And it turns out there’s a lot of variation around Australia which you would expect in what we understand from the modern-day climate and for example in the Sydney region there are six distinct regions, from Port Jackson south through the Shoalhaven River. And they relate to climate features as well as environmental events like plant flowering, fruiting and animal behaviour and for example April is known as the arrival of winter rains and cooler temperatures, at a time where Lilly Pilly or the bush cherries begin to fruit and you might even notice things like this in your own garden so just that tuning into the landscape and watching things change.

So there really is a wealth of untapped indigenous weather knowledge in the form of stories and luckily knowledge about the weather is not secret business, it can be shared with anyone. So there’s really a lot we can learn from the first Australians about our natural climate cycles but also about caring for country, about being better custodians of the land on which we live.

But long before humans were keeping weather records, were telling stories, the natural world has been busy tattooing the passing of time year after year for centuries. An incredible amount of information lies in the stories held in ancient tree rings, in coral skeletons, in air bubbles trapped in ice. This lies well beyond our society’s collective memory and so these biological and geological indicators are really important natural archives which have this seasonal and annual banding which allows us to directly compare to instrumental weather records, which allows us to extend our understanding of natural variability back in time. And this field of science is known as paleoclimatology and paleo just means ancient and climatology is just all of accumulated weather and what this does is provide estimates of preindustrial or natural climate variability and this allows us to assess recent climate extremes and their causes.

And I was involved in a global effort to consolidate these types of records from all over the world but in particular I was looking at the Australian region and this was part of an international effort to develop temperature reconstructions from different parts of the world. And I was leader of the Australasian group so Aus2K which looked at Australia and New Zealand and the surrounding waters from 2009 through to the project’s end last year. And our team at the University of Melbourne developed the region’s first 1,000-year temperature reconstruction so you can see in this image people were looking at reconstructing temperature from the Arctic, the Antarctic, North America, Asia and so our effort was to try and bring together our records form our region.

And what that looks like is this so this black line is showing you year by year temperatures back 1,000 years using things like tree rings and corals and icicles for our region. The red line just represents direct instrumental temperature observations and what we found is that the warmest 30-year period in the last thousand years occurs in the most recent period, from 1985 to 2014 which is the last year that we analysed in the record.

We also looked at climate model simulations to try and get a sense of what might be causing this and it turns out that greenhouse gases from human activity are required to reproduce the rate and the magnitude of the warming observed in our region since 1950. So it’s no longer just natural variability, we’ve got something else in the system now. So this was important because although this conclusion had already been seen in the instrumental record, it was the first time we were able to look at it independently using these natural archives.

To my surprise this provoked major backlash from climate change sceptics. From 2012 through to 2016 our team received abusive emails, legal Freedom of Information requests for four years’ worth of our email correspondence to see if we were reverse engineering our results and so on, hate mail, harassment and it had a very high personal toll. And I was very lucky to have a terrific mentor in Professor David Karoly, some of you in the audience might have heard of him and also a really terrific group of friends to get me through what was a fork in the road for me. I thought well I’m really interested in this work but it’s a pretty high personal toll.

Thankfully it all wasn’t bad. During this very difficult time associated with temperature reconstruction we were very honoured to receive this major national science award, the Eureka Prize for Excellence in Interdisciplinary Scientific Research which is known as the Oscars of Australian science which is why we look like that. And the Search project won this award for reconstructing and consolidating our climate history using historical documents, these early weather records and paleoclimate data. And we were also up against pioneering medical research so it wasn’t just in the area of climate science and so we were totally blown away when we got the gong. And the core team was made up of early career women and so that was also I think a really important component because I think it’s actually fostered significant progress in this field, emerging field of historical climatology.

So what does looking at the past help us understand about modern weather and climate extremes that we are actually now seeing? Is it just a case of history repeating? And I think in a country like Australia because we are the land of drought and flooding rains people dismiss it as being an issue of oh we’ve been through it all before. So I’d like to highlight a few examples of how our extremes are changing.

So following an exceptional two-week heatwave that swept across South Australia and Victoria during the height of a brutal 13-year drought, ferocious bushfires blazed across Victoria on the 7th of February 2009 and many of you would know that as the Black Saturday fires. Melbourne set a new temperature record of 46.4 degrees on the 7th of February, it was a full three degrees higher than the old February record and 0.8 degrees hotter than the all-time record of Black Friday in 1939. The conditions were so extreme that it redefined the way severe bushfire conditions were rated in Australia. A new catastrophic fire danger level actually had to be developed to actually accommodate the unprecedented fire weather conditions.

Entire towns like Marysville, just 100km to the northeast of Melbourne were effectively wiped off the map. The fires killed 173 people and destroyed over 2,000 homes and a further 374 died in the preceding heatwave which is more than double the number from the fires themselves, causing the state morgue to overflow and I detail some of this sort of stuff in the book but I haven’t got time here. And while 173 people lost their lives during the fires the RSPCA estimates that more than one million animals perished. Many severely injured animals had to be put down and habitat loss can last for some time in intensely burnt areas as trees and understorey need some time to recover. And so the true extent of the impacts of the Victorian bushfires on wildlife may not be known for many years. And while an economic cost of $4b worth of direct damage has been estimated it doesn’t take into account these intangible ecological and environmental impacts that are hard to estimate.

So what does the historical record say? Well 158 years earlier almost to the day on the 6th of February 1851 the Black Thursday bushfires blazed across Victoria. The descriptions of scorching winds, flames and blazing cinders sweeping through Melbourne obscuring the daylight until men cried out in the fear of the day of judgement. Ashes were falling everywhere and the wind was like a blast from a furnace. Candles had to be burned in the houses to see. The people of Melbourne were terrified by the ferocious conditions and people had to flee the fires by rowboat. And we were lucky to come across an instrumental weather record for this particular event and we found a maximum temperature of approximately 42 degrees recorded from the historical record compared to 46.4 from the 7th of February 2009.

The other interesting thing about this particular fire is that it burnt an area that was 10 times the area of the Black Saturday fires which is about 20% of the area of the state of Victoria. Which is remarkable when you actually think about it. So perhaps it suggests we have not seen the full extent of our natural climate variability meaning that our estimation of future risks are likely to be underestimated and so piecing together our climate history for the first time has provided an unparalleled perspective on the past and just how vulnerable Australian societies are to weather and climate extremes. And Australia’s warming climate has caused an increase in extreme fire weather and the length of the fire season across large parts of Australia since the 1970s so we’ve been able to directly observe that.

And these increases in extreme fire weather conditions is entirely consistent with the state of the art climate change projections provided by the CSIRO and the Bureau of Meteorology. And so what I’m showing you here are the average temperature increases we can expect on a business as usual emissions pathway by the end of the century. And while there are differences in the climate change projections for each region of Australia the average temperature increase across the country will typically be 4 degrees by the end of the century based on our current trajectory.

The biggest changes will impact inland Australia where up to 5.3 degrees of warming is projected. So it’s very likely that parts of the outback will record summer temperatures in excess of 50 degrees Celsius making much of inland Australia increasingly uninhabitable. This will have major impacts on desert tourism in places like Uluru which is a major contributor to the Australian economy.

Extreme heat is also an issue on the coast. In the summer of 2016, 2017 was the warmest on record for Sydney, it was a huge 2.8 degrees above average. For example in the western suburbs of Sydney maximum temperatures soared to 47 degrees, the highest February temperature ever recorded in the Sydney basin. So based on the recently observed increase in extreme temperatures it’s very possible that future summers in Australia’s most densely populated cities, places like Sydney and Melbourne will soar past the 50-degree mark in years to come.

So Australian temperatures have increased by about 1 degree since Dorothea Mackellar wrote her famous poem but all natural variability is now occurring on the background of this warming climate and I think that’s the really important thing we need to be thinking about. So the number of extreme heat days, the warmest 1% of temperature records, experienced across Australia are now happening more often as you can see in this graph. According to the Bureau of Meteorology seven of Australia’s 10 warmest years on record have occurred since 2005. 2013 was our warmest year. Earlier this week Sydney experienced its warmest April day on record reaching 35.4 exceeding average temperatures for April by more than 10 degrees.

So it’s now possible to run climate modelling studies that compare the likelihood of an extreme event happening in a world with greenhouse gases from human activities to a world with just natural variability and this field of science is known as detection attribution and Australian researchers are world leaders in this emerging area of science. And there’s been a study done by actually Sophie Lewis that’s shown that temperatures experienced during Australia’s warmest year on record in 2013 was found to be virtually impossible to achieve without the presence of human influences on our climate so our climate is changing.

And hotter temperatures means changes to our rainfall so when we have more heat in the system this means more evaporation increasing the amount of water vapour that’s available in the atmosphere to fall as rain and a warmer and wetter atmosphere causes an increase in extreme rainfall in between periods of severe drought which has major impacts on communities and our environment. So as the climate continues to warm we can expect longer and hotter droughts followed by torrential deluges.

And the climate conditions experienced over the past 20 years are a clear example of what can be expected. The millennium drought affected south-eastern Australia from 1997 to 2009. It was the lowest 13-year rainfall period in the historical record. The rainfall deficits were nearly double the previous records set during the world war 2 drought and this had major impacts on the Murray Darling Basin which is Australia’s food bowl. Rivers ran dry. This is the Darling River in December 2006 in New South Wales.

So while we’ve always experienced drought in Australia our droughts are now even hotter than they were in the past. Australia’s average temperatures have increased by about a degree with about 0.7 of that warming occurring since 1950. And work we did during the Search project calculated that the Murray River streamflow deficits experienced during the millennium drought were a one in 1,500-year event so statistically a very rare event. And that Australia being Australia the drought broke spectacularly from 2010 to 2012 during a La Nina event which brings a lot of rainfall to eastern Australia and resulted in the nation’s wettest two-year period on record.

And this resulted in 78% of Queensland being declared a disaster zone and alarmingly history tells us that the floods of 1893 and 1974 were a lot worse in terms of some of the flood heights, were about 2m higher in some cases and I detail this in the book. But what this does is highlight our vulnerability to extremes. The floods had devastating impacts on local communities, over 2.5 million people were affected by widespread property damage, their homes submerged in brown floodwaters for days, caking all of their possessions in silt and mud as you can see in the foreground of this image.

The Queensland floods had a colossal price tag of about $14b making it Australia’s most expensive flood disaster on record. And coping with loss and change can be psychologically really difficult. This Grantham local, Derek Schultz, says his spirit was broken when the Queensland floods destroyed almost everything he had ever known as home. And more than one in 10 people exposed to natural disasters are reported to develop psychological distress with some symptoms persisting for the rest of their lives. Suicide rates in regional Australia spike during droughts so even our toughest farmers are really suffering.

It’s a very clear example of the destructive sequence of extremes from severe drought into exceptional flooding. And what this does is when you get all of your rainfall in one hit it can cause flash flooding which instead of allowing groundwater to recharge, it just strips precious topsoil and becomes more destructive than is actually a good thing. And it’s very hard to recover from these back to back disasters financially and also psychologically, it wears down the resilience of people and communities.

So it’s clear that Australia’s climate has become more extreme as the planet has continued to warm. So what does this mean for future life as Australians and does it even matter?

Well Australia’s considered to be one of the most megadiverse countries on the planet along with places like Brazil, Madagascar and Papua New Guinea. We have the highest number of native plants and animals that are only found here and nowhere else on earth. Our incredible environmental heritage underpins our economy in the form of agriculture, tourism, fisheries as well as our health, our lifestyles and safety that we all enjoy as Australians. But when it comes to climate change we are recognised as the most vulnerable nation in the developed world.

So the land of drought and flooding rains is becoming even more extreme in a warmer world. And nowhere is this more clear than the Great Barrier Reef over the past two years. The Great Barrier Reef snakes over 2,000km of the Queensland coast and contains – is home to the largest collection of corals with a stunning array of tropical fish and marine life. There are even sea turtles that can live over 100 years and it’s actually the largest living organism on the planet.

The Great Barrier Reef has economic, social and icon asset value of 56 billion, it supports 64,000 jobs and contributed 6.4 billion to the economy in 2015/2016. It’s listed as a UNESCO World Heritage site as it is a globally recognised area of exceptional biodiversity. David Attenborough describes it as the world’s most beautiful natural wonder that he’s experienced in close to 70 years of documenting the natural world.

Then on the background of the world’s warmest year on record, in 2016 93% of the Great Barrier Reef bleached. Thirty per cent of corals turned white and died from heat stress associated with high ocean temperatures. So just like on land you can get heatwaves, you can also get these marine heatwaves. And mass bleaching of coral reefs was only first described in the scientific literature during the 1980s, really in the Caribbean. In our region it was very rare.

And then tragically in 2017 two-thirds of the reef bleached again causing a further dieback of 19% of corals. So this event actually has the disturbing record of being the only back to back coral bleaching event in recorded history. And what this has resulted in is 50% of the corals of the Great Barrier Reef are now dead. I’ll say that again, 50% of the Great Barrier Reef’s now dead. Scientists have called it that – as the reef is now in a terminal state of decline. It’s a profound loss not just for Australians but for all of humanity.

Climate modelling studies now compare the likelihood of an extreme event happening in a world with greenhouse gases from human activities to a world with just natural variability and researchers from the University of Melbourne have calculated that mass bleaching was made 175 times more likely because of climate change. And under business as usual emissions, 99% of the world’s coral reefs are predicted to bleach every year by 2043, just 25 years away.

Another major change taking place in our coastal environment is an increase in sea level. Global sea level rise is currently underway and in places like western Antarctica it is now considered unstoppable by gl – by experts. At least 1m of sea level rise is considered likely by the end of the century. And in May last year a new US report was released revising its physically plausible global sea level rise estimates, revising it to as much as 2 to 2.7m by the end of the century based on high emission scenarios. And Coastal Risk Australia have actually mapped the inundation risks associated with a 2m sea level rise at high tide around Australia. The image I'm showing you here is the coastal inundation risk associated with this 2m sea level rise at high tide for Sydney by the end of the century.

Many of Australia’s most densely populated areas will be at risk of becoming uninhabitable or subject to an increased risk of inundation by destructive storm surges as the sea level rises. For example in Sydney, Circular Quay, Royal Botanic Gardens and Woolloomooloo will be inundated. Airports in Sydney, Brisbane and Hobart will be largely under water by the end of the century if this projected 2m rise comes to pass. Events that used to be considered floods in our present climate will just be the new high tides in the future.

In this future maps of the world and not just in Australia will have to be redrawn as the sea level rises and new rainfall and temperature patterns sculpt new landscapes and coastlines in response to a drastically altered climate. And just as a reminder 85% of the Australian population lives in the coastal zone. So any rise in sea level amplifies the threat posed by high tides and storm surges associated with intense low-pressure systems like tropical cyclones or severe east coast low storm systems to communities and infrastructure close to the coast.

At Fort Denison in Sydney Harbour there’s been an overall rise in sea level of about 5cm between 1966 and 2010 and while this might not sound like much it means the difference between your home being safe and dry or flooded by high tides and storm surges. And this is what that looks like. During a series of east coast lows in June 2016 a storm surge caused extensive flooding and damage to coastal infrastructure from Queensland to Tasmania. The enormous scale of the event was unusual, a few hundred kilometres are more common for these kinds of events rather than vast tracts of the eastern seaboard.

And although the system was only associated with a relatively moderate storm surge of around 30cm it combined with high tide generating damaging waves that resulted in local inundation of low lying areas and widespread erosion along the New South Wales coastline. In places like the northern beaches in Sydney large chunks of the beach were gouged out by huge 8m waves. Some residents of Collaroy reported having 20m of their backyards washed away by the storms.

So it’s clear to me that we are now facing the largest intergenerational ethical challenge in human history. If we continue along our current high emissions path global average temperatures are projected to increase between 2.56 to 4.8 degrees by the end of the century. Three degrees is considered likely and that represents an overshooting of the upper limit of the 2-degree target set by the United Nations Paris agreement which looks to try and put the brakes on the dangerous level of climate change.

This figure shows the intergenerational legacy of global warming and many people in the room tonight will live to witness these changes and if you won’t be around then it’s likely that your children or your grandchildren will inherit this apocalyptic future. The science is crystal clear. Climate change is happening right now, we’re already committed to dangerous levels of climate change and Australia is the most vulnerable nation in the developed world. Out of the top 60 emitters worldwide Australia is ranked 57th in terms of its climate change performance index, ranked as a very low-performing country, only ahead of Korea, Iran and Saudi Arabia.

I believe that we can do better and what we do now will shape life in Australia and how much will be lost to future generations. Putting the brakes on greenhouse gas emissions will help reduce the level of dangerous climate change that we experience. It’s a little bit like addressing a treatable health condition sooner rather than later to avoid the worst-case scenario. The question is, and I think it is as simple as this, is do we want to leave future generations with a stable and a liveable climate that most of us have enjoyed?

The good news is that all the technology we need to limit the amount of dangerous climate change that we will experience already exists. There is a clean energy revolution already happening all over the world and even here in Australia. And according to our clean energy regulator more than one in five Australian households now have solar panels installed on their roof, the highest per capita in the world. Queensland is the leader in household solar, nearly a third of households in the sunshine state now have solar rooftops. And given that Australia’s drenched in sunshine I think it’s quite insane that only 3% of the country’s electricity is generated from solar energy. Huge untapped potential exists.

And what you sometimes don’t hear or not very often at all is that the renewable sector is already creating nearly double the jobs generated by the local coal mining industry, suggesting that the tide has already turned on Australia’s clean energy revolution. And there are a growing number of credible studies from the CSIRO and others detailing scenarios to achieve 100% reductions in Australia’s greenhouse gas emissions from all sectors, not just from electricity but also things like agriculture and transport. And there’s this quote that I really like from Al Gore which says we’re in the midst of a sustainability revolution that has the magnitude of the industrial revolution but the speed of the digital revolution. So once we get behind this we’re away. So I believe we are witnessing a pivotal moment in human history that signals the end of the era of polluting fossil fuels and the dawn of the clean energy revolution. We need to strengthen political will to move away from fossil fuels and invest in a clean energy future.

The other bit of good news is that Australia has a long history of local communities taking a stand for environmental protection and social justice. An iconic example is the fight to protect the Tasmanian wilderness areas during the late 1970s and the early 1980s. Peter Dombrovski’s photo of Rock Island Bend came to represent the beauty and the vulnerability of the Franklin River and have helped influence the outcome of the federal election in March 1983. Sometimes it helps where we can actually see what it is that we have to lose. The Franklin Dam was never constructed because of community backlash. The new government under Bob Hawke stopped the dam from being built because it was deeply unpopular with voters. And the movement eventually led to the project’s cancellation and became the most significant environmental campaign in Australian history.

Some people here in the room would be aware that the federal government is planning to develop the biggest coal mine in Australia, the Carmichael Mine, near Bowen in Queensland with Indian mining company, Adani, despite overwhelming evidence that fossil fuel burning is causing dangerous levels of climate change and that the world needs to transition to renewable energy immediately to avert disaster. The Stop Adani movement is now made up of millions of individuals and community groups across Australia. The movement has engaged people from all walks of life from farmers, indigenous people, environmentalists, the young, the old.

Former Greens Senator, Bob Brown, has said that stopping the Adani coal mine is this generation’s most urgent call to action. There are grave concerns at the enormous scale the proposed coal exports will threaten an already struggling Great Barrier Reef as the terminal is located on the coastline of the UNESCO listed world heritage area. And aside from being completely inconsistent with needing to transition to renewable energy of huge concern to local farmers is the fact that the mine will use approximately 12 billion litres of water each year which threatens to dry out the groundwater necessary for the viability of agriculture in the Great Artesian Basin.

The government also passed a controversial bill to amend native title legislation making it easier for companies like Adani to create division among indigenous communities by only seeking partial instead of unanimous support previously needed for these controversial projects.

Psychology tells us that blocking feelings of empathy and concern to avoid psychological pain is a common human defence mechanism that is designed to protect us from becoming too emotionally overwhelmed. It’s deeply human to turn away from pain. Endlessly distracting ourselves in mundane matters is a way of psychologically distancing ourselves from feeling conflicted and distressed by the realisation that we individually and collectively have an ethical dilemma around caring about each other and the future of all life on the planet.

The time has now come to connect our head with our heart and open ourselves to the loss but also the vast opportunities that we now face. It’s not the time to look away and disengage, it’s the time to have your voice heard even if you are an introvert like me and would probably prefer to be tucked away in a hollow somewhere. But that’s where inspirational quotes come in so Martin Luther King, he says our lives begin to end the day we become silent about the things that matter. And many community groups from the young to the old are now taking a stab at the things that really matter. We are witnessing a pivotal moment in human history, it is an invitation to exercise your power as a citizen and as a consumer to help write the next chapter of our history, the one where we finally take a stand for an environmentally sustainable future on planet earth and protect our magnificent sunburnt country for future generations. Thank you.

Applause

M:        Thank you, Joelle. I’m just thinking about connecting hidden heart here. Joelle mentioned a study by Sophie Lewis and the reason she looked at me is that Sophie’s my daughter-in-law and she’s also the mother of my granddaughter so over the last kind of year or 18 months we’ve had many intense family conversations about what it means to bring a new child into the world when you’re a scientist and you actually know what’s ahead so hidden heart connected here and thankfully we’ve got people like Joelle to put those stories together for us as well.

So I think it would be – we’ve just got time to have a few questions from the audience Now I'm going to ask for the usual routine, if you’d like to ask a question would you please put your hand up and wait for a microphone so that our hearing loop can work and I’ll pick you out there so okay. Middle first. Sorry, sir, I’m only pointing at you so it’s easier to find the microphone.

A:        Thank you for that wonderful talk, Joelle. That was pretty amazing and that’s why we come to hear. Very depressing ‘til halfway through and you presented some hope for the future. I’m not surprised that there are not many young people in the audience, I think it’s all a bit too much for them. I’m interested in the flood part of it. You mentioned about increased precipitation but unfortunately is that not just the end of the story? I mean there’s no pattern and there’s no – yeah, that’s –

J:          Well Australian rainfall is notoriously tricky to study because we have a lot of drivers or a lot of influences on our natural rainfall variability so the largest one is the El Nino southern oscillation so you might have heard of El Nino and La Nina and there’s also influences from the Indian and Southern Oceans so it is difficult to get a sense of – there’s a lot of complex influences on Australian rainfall. And some of the climate change projections are more uncertain when it comes to rainfall but just in terms of the general physics what I outlined there is effectively what it represented in the CSIRO projections so just generally speaking for most – where most of the Australian population is, is what I outlined this evening.

A:        Thank you. The blackouts in South Australia recently when the tornados knocked down the power poles. To what degree do you think that amount of blackout was caused by the amount of solar and green energy in South Australia?

J:          Well it’s my understanding that was just – there was an extreme weather event that led to that, I don’t think it really had anything to do with the capacity of the system to cope but it was just that - also standard poles and wires also went down, it wasn’t really a case of – that was jumped on for political reasons and I think that actually obscured public understanding but I think that was a case of conflation if you like.

A:        Thank you. I’m interested in what strategy you’ve got in place, your group, your research group has in place to influence government policy in this area. I know you’ve got public fora like this where you can get people to support you but I think as researchers you have a responsibility to try and influence government policy, evidence-based policy so do you have a strategy for that and if so what is it?

J:          Okay, there’s probably three things I can say to that. My senior colleague, Professor David Karoly does a lot of work working on that policy science interface and he’s a good representative for our community and there are others, Will Steffen that’s here in the room as part of the Climate Council. So that’s one thing. Secondly some scientists – it’s a double-edged sword, a lot of scientists just like to take that approach of just providing the science and not taking that next step to try and translate it out. What I’ve done on a personal level is write this book which I hope will be helpful and I’ve written it in a way that you don’t need to be a scientist to read it, it tells stories from our history and it explains a whole range of things and joins those dots so it’s a great question and I think it depends a lot on your career stage, it depends on your temperament but I think our community is trying to do a lot more to try and bridge those gaps.

I’m also involved with a group called the Wentworth Group of Concerned Scientists in Sydney and they do a lot of work in the environmental policy space so people like me are being trained up I guess to do that type of work. But it’s not for the fainthearted, it’s a different field than a lot of scientists – we are trained in the physical science, a lot of us don’t have that communication training or background or dare I say interest because it can be a bit rough and tumble as we discovered – as I discovered and so I think we have this interesting situation where it also helps when the community takes a stand and votes on local, state and federal levels because it’s not just up to us and this is why – part of the reason why I wrote this book is because I think now I feel like it’s a little bit off my shoulders, it’s out there. I just told you. It’s been out there for a long time but in the Australian context it’s the first time we’ve been able to piece it together, the missing piece of the puzzle was history and thankfully we had a lot of help from places like the National Library to piece that together and I think we can do better, I think there’ll be more work but this is just our first pass. I’ve had a good go at it, mind you but what I'm saying is that there’s just so much more we can do in this area. And so I hope that answers your question.

A:        Thank you. Is this on? Okay, thanks, Joelle, that was very interesting. I’ve read recently some figures quoted from the UN and I presume that means from the IPCC that indicate that 95% of the greenhouse gas that we’re worried about up there is water vapour, 5% is made up of other gases, a bit over half of which is carbon dioxide so about 3%. Of that 3%, 97% is contributed to by natural sources. Now if all of that’s correct we’re looking at 0.09% of all of the greenhouse gases surrounding the earth –

J:          So could I just interject there? The thing there is the global warming potential of different gases so CO2 has the capacity to heat the atmosphere a lot more than water vapour and also methane is another one of these gases that’s of concern so it’s not really a helpful way of thinking about it in terms of total volume.

A:        I was going to ask you the question, how – if it’s 0.09% of all of those greenhouse gases that we’re concerned about being that it coming from us if you like how can the world have a significant effect on that? And indeed here in Australia how can we have a significant effect of it if we’re 25 million people out of 7 billion in the world?

J:          Okay so I do outline some of these major I guess contrarian claims around the climate science in the book so I'm not sure how helpful it is to go into that right now. In terms of the Australian contribution to the global emissions so we contribute about 1.3% of global emissions but if you add up all the countries that are under 2% pretty quickly that adds up to 40% of global emissions so I don’t think it’s helpful to think well we only have 1.3 and so we can shirk our responsibility as global citizens. So –

Applause

A:        Thank you very much. I’m a fairly observant and committed gardener and bushwalker and for many years – I’m in my 60s now – for many years I’ve seen plenty of anecdotal indicators of climate change and I’ve taken it as given that climate is changing. You’ve said that the analysis described in your book confirms that to be so. I guess the scientific – my question is the scientific community now accepts that the climate change is a fact but to what extent is – does the scientific community agree on the extent to which human activity is a contributor?

J:          So 97% of publishing professional climate scientists agree that humans are causing climate change so that’s the level of consensus we have within our professional community. I think Will would agree with that. And so I think there’s sometimes this false debate that plays out in the public domain around this idea that we have unsettled science and we don’t really know. Actually there’s a vast body of information that exists and what I’ve tried to do in this book is to draw together the state of the art understanding from past, present and future in – for the Australian context to help people like yourselves piece it together.

A:        So 97%, you’d think that’d be enough consensus to convince governments everywhere of the urgency of action.

J:          And that’s where people like yourself, sir, come in because if we aren’t exercising our democratic right to vote in terms of – at all levels from state through to federal, I mean this is where it’s not just our problem as the scientific community – I’d like to put that out there, we are doing our best but a lot of us you know we are responsible for developing fundamental research in the climate system and that’s our job. This type of work is fairly rare for us to do because – for multiple reasons but mostly because a lot of scientists would prefer to crunch numbers and code and – rather than write books. So you got me and I –

Applause

J:          Thank you. And I hope that I’ve done a reasonable job of translating it on behalf of our community.

Applause

M:        One last question from the lady.

A:        Hi Joelle, thank you for your talk. We’re here to represent the younger generation.

Applause

J:          Thanks for being here.

A:        No worries. I just had one question, I was wondering as the younger generation going forward what are some major things that we can implement in our life to help with climate change? So you mentioned the solar panels and that’s great and also getting involved in government and they’re great things but is there anything else in our everyday life that you recommend or you’ve seen through research that works?

J:          Yeah so I think - in the book – I have a section on this in the book towards the end which I hope is helpful. The two main things I think are really important is exercise your power to vote, I can’t say that enough, from local, state through to federal levels, by education yourself and becoming an environmentally aware person and you will live to see this, this is the thing you know and me too, I mean it’s one of those things that if we don’t take a stand for the things that matter then it just flies under the radar so – and unfortunately - and I understand and I teach university undergraduate students and some of them tell me like I just feel so disillusioned, I don’t know what to do but I just say hang in there you know you’re becoming scientifically literate, that’s really important and become a person that’s able to share that information with the people around you. And there’s also things you can do on that individual level as a consumer, how you choose to power your home and insulation and all these different things that you can do so putting your money where your mouth is and living your ethics plus a range of other things. But I think at its core if I had to boil it down to one is waking up and caring and it’s just at its most fundamental level is actually caring about this. That’s what I think.

Applause

M:        Well thank you and in fact the representatives of youth here, enrol the next kind of 18-year-old that you know to vote, please, and make them do it. They don’t realise we have this hard won right and that they’re not exercising it so I think that’s a really – a good piece of practical advice.

Now we do need to bring our evening to a close. If you’d like to explore this subject in more depth copies of Joelle’s book are of course available in our beautiful bookshop up in the foyer on your way out and Joelle would be very happy to sign copies for you and for tonight only, because we’re a very generous library, we’ll give you a 10% discount if you buy her book. So thanks for coming tonight, I wish you a good evening, hope you’ll come to the Library again soon but please join me again in thanking Joelle for her talk tonight.

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End of recording