New climate modelling suggests planetary crisis is coming much sooner than previously thought
Joëlle Gergis
Dr Joëlle Gergis is an award-winning climate scientist and writer from the Australian National University. She is an internationally recognised expert in Australian and Southern Hemisphere climate variability and change based in the Australian Research Council (ARC) Centre of Excellence for Climate Extremes. Her research focuses on providing a long-term historical context for assessing recently observed climate variability and extremes. In August 2018 she was appointed to the Climate Council, Australia's leading independent body providing expert advice to the Australian public on climate change and policy. Her book, Sunburnt Country: The future and history of climate change in Australia, is now available through Melbourne University Publishing. |
I keep having dreams of being inundated. Huge, monstrous waves bearing down on me in slow motion. Sometimes I stop resisting and allow myself to be sucked in. Other times, I watch as a colossal tsunami builds offshore. I panic, immediately sensing that I don’t stand a chance. I watch the horizon disappear, before turning to bolt to higher ground. Around me, people are calmly going about their business.
High water is menacing my subconscious, trying to help me grapple with the overwhelm I feel in my waking life. My teeth ache from the nocturnal grinding that my dentist now just acknowledges with a sigh.
As one of the dozen or so Australian lead authors involved in writing the physical science basis of the “Sixth Assessment Report” of the United Nations’ Intergovernmental Panel on Climate Change (IPCC), it’s no wonder I’m on edge. Before the coronavirus pandemic swept the world, the scientific community was reeling from the most catastrophic bushfire season in Australian history.
We all watched on in horror as the fires savaged our country, releasing more carbon dioxide in a single bushfire season than the country emits in an entire year.
An arc of destruction tore through our native forests; from the subtropical rainforests of Queensland, through the temperate forests of southern New South Wales and eastern Victoria, all the way across to the coastal bushland of South Australia.
A terrifying amount of Australia’s World Heritage areas were burnt – at least 80 per cent of the Blue Mountains protected area and 53 per cent of the ancient Gondwana rainforests network.
These are the “last of the last” of such precious places. Areas that have clung on since the age of dinosaurs, forced to contend with the processes of evolution playing out in fast forward. Instead of adapting gradually over thousands or millions of years, ecosystems were radically transformed in the space of a single summer, not even a nanosecond in geologic time.
The urgent national conversation we needed to have about climate change following this collective trauma never happened; instead, we were all forced to retreat into our boltholes as a deadly plague took hold. We abandoned the global common, and life shrunk to an intensely personal scale.
And there we have remained, in suspended animation, waiting for the health crisis to pass, for some air of normality to return to our lives.
Through it all, scientists across the world have been working around the clock to progress the IPCC’s monumental assessment of the global climate – a cycle that typically takes around six years to complete.
As part of this effort, a group of Australian scientists published an analysis of the latest generation of climate models, assessing what they are telling us about Australia’s future. After years of refinements, the new models now contain significant improvements in the simulation of complex physical processes associated with clouds and convection, essentially the transfer of heat through the fluid motion of the atmosphere and ocean. These updates have influenced estimates of what is termed “climate sensitivity”, a measure of the relationship between changes in carbon dioxide in the atmosphere and the corresponding level of warming.
The results have provided an alarming revision of the temperature increases we thought possible. It is something IPCC scientists are grappling to understand and communicate, as it has dire implications for the feasibility of achieving the Paris Agreement targets for reducing global emissions.
The current goal is to keep global warming to well within 2°C above pre-industrial levels, and as close to 1.5°C as possible. This is to avoid instabilities in the planetary processes that have kept our climate steady for close to 12,000 years. That is, for all of modern human civilisation.
According to this new study, led by scientists at the CSIRO and Bureau of Meteorology, the worst-case scenario could see Australia warm up to 7°C above pre-industrial levels by the end of the century. On average, the results from 20 models show a warming of 4.5°C, with a range of between 2.7°C and 6.2°C.
As two of the study’s authors, Michael Grose and Julie Arblaster, noted in The Conversation, “the new values are a worrying possibility that no one wants, but one we must still grapple with”. They quoted the researchers of another recent climate study, who said, “what scares us is not that the models’ [equilibrium climate sensitivity] is wrong … but that it might be right”.
Another profoundly significant result is buried 16 pages deep into the paper. The scientists show that this revision now means that 2°C of global warming is likely to be reached sometime around 2040 based on our current high-emissions trajectory. The implications of this are unimaginable – we may witness planetary collapse far sooner than we once thought.
I was so disturbed by the new model results that I found it impossible to get back to my work. How can we not understand that life as we know it is unravelling before our eyes? That we have unleashed intergenerational warming that will be with us for millennia? If this really is the end of days, how can a climate scientist like me make best use of the time I have left?
In recent years, I’ve looked to brave colleagues who are becoming increasingly vocal about the climate emergency. One of the scientists I admire most is Professor Terry Hughes, one of the world’s leading experts on coral reefs, and our foremost authority on the Great Barrier Reef.
In late March, just before the national lockdown took effect, Terry and his colleagues rushed to conduct an aerial survey of the third mass-bleaching event to strike the reef since 2016. It is the first time that severe bleaching impacted upon virtually the entire range of the Great Barrier Reef, including large parts of the southern reef spared during the 2016 and 2017 events. It’s hard to hide from the reality that the entire system is in an advanced state of ecological collapse.
In desperation, Terry took to Twitter, sharing his experience of surveying the carnage: “It’s been a shitty, exhausting day on the #GreatBarrierReef. I feel like an art lover wandering through the Louvre… as it burns to the ground.” By the end of his fieldwork he was a broken man: “I’m not sure I have the fortitude to do this again.”
The honesty of his despair allowed my own to crystallise into a visceral sense of dread that is deepening by the day. We have arrived at a point in human history I think of as “the great unravelling”.
Recently, I shared a statistic with my climatology students as I explained the latest mass-bleaching event: 99 per cent of the world’s tropical coral reefs will disappear with 2°C of global warming. This future no longer feels impossibly far away, it’s happening before our eyes.
Looking around the room, I couldn’t help but feel sorry for them. They have inherited a planetary mess, yet are more distracted and disconnected from each other, themselves and the natural world than any generation that has ever lived.
As each season passes, it’s painfully clear that we are witnessing the destabilisation of the Earth’s climate. There are things we can still save, but it’s now too late for some areas such as the Great Barrier Reef and tracts of ancient rainforests.
In Australia we wear our badge of resilience with a hefty dose of national pride. But scientists on the frontline of the climate crisis understand that some things in life, once gone, can never be replaced. If the new models turn out to be right, there is no way we can adapt to the catastrophic level of warming projected for a country like Australia.
Even placing the new models aside, the 2019 UN Environment Programme’s “Emissions Gap Report” shows that a continuation of current global emission reduction policies could see the Earth’s average temperature rise a staggering 3.4 to 3.9°C by 2100.
If we continue along our current path, by any measure, we will sail past the Paris Agreement targets in a handful of decades.
Some of our most precious ecosystems will never recover, including some of what was destroyed in Australia during our Black Summer. Gutted landscapes will struggle on, trying to regain some semblance of an equilibrium. But the truth is the destruction we have unleashed will reverberate throughout the ages.
We are witnessing the unthinkable. Facing the unimaginable.
Psychologically, many people already sense it’s the beginning of the end. But is this the end of the era of fossil fuels, or life as we know it? As the planetary crisis accelerates, we must confront the reality that what we do now will forever alter the course of humanity and all life on Earth.
My dreams are warning me that a metaphorical tsunami is approaching, threatening to destroy all that we hold dear. We must wake up and rush to higher ground before it’s too late.
Links
- Dr Joëlle Gergis: Sunburnt Country: The History and Future of Climate Change in Australia
- Dr Joëlle Gergis: The Terrible Truth Of Climate Change
- Dr Joëlle Gergis: Google Scholar
- Dr Joëlle Gergis: Journal articles, books and book chapters
- Global Paris pledges need to triple to stay within 2C of global warming
- The First Fleet and Australia's unforgiving weather
- In the hot seat: Joelle's journey from the dole to a global role
- The Industrial Revolution kick-started global warming much earlier than we realised
- Northern NSW is no stranger to floods, but this one was different
- Can art put us in touch with our feelings about climate change?
- Post-1950s warming in region unmatched in 1,000 years
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