Despite all the political rhetoric you might have heard in the news, the scientific reality is that the planet is still on track for catastrophic levels of warming, writes Joëlle Gergis, from The University of Melbourne in this piece republished from The Conversation.
In February 2024, I attended the annual conference of the Australian Meteorological and Oceanographic Society – the peak group for scientists working in all branches of weather and climate research. Over the past decade, the mood of our gatherings has become increasingly sombre. Some presenters have taken to apologising in advance for their confronting results, with some attempting to soften the blow by including funny animated gifs or photos of soothing sunsets to comfort the audience.
It’s not hard to understand why. This year we had a plenary address by a distinguished IPCC veteran. The speaker began by saying that the world has “Buckley’s chance” of achieving the 1.5°C target, and even 2°C is going to be a stretch. If emissions continue at the current rate, the 1.5°C threshold could be breached as soon as 2028.
Forget the critical decade, what happens every single month during the next handful of years is crucial in determining how quickly we drain the remaining carbon budget needed to achieve the temperature goals of the Paris Agreement.
People who have been working in the field for decades are no longer sugarcoating the bad news – they want us to feel an appropriate level of alarm and outrage so we can get on with the job of doing something about the terrible situation we find ourselves in. We need you to stare into the abyss with us and not turn away.
Even a cursory look at the latest figures released by the United Nations Environment Programme (UNEP) shows that the situation we are facing is extremely serious. The 2023 Emissions Gap Report – subtitled “Broken Record: Temperatures hit new highs, yet world fails to cut emissions (again)” – explains that, even in the most optimistic scenario, the chance of limiting global warming to 1.5°C is just 14%, with various scenarios indicating a 90% probability of warming between 2°C and 3°C by the end of the century.
If currently implemented policies are continued with no increase in ambition, there is a 90% chance that the Earth will warm between 2.3°C and 4.5°C, with a best estimate of 3.5°C.
Despite all the political rhetoric you might have heard in the news, the scientific reality is that the planet is still on track for catastrophic levels of warming. Even if nations make good on their net zero promises – which is a big “if” because right now many nations’ pledges have no finance, weak implementation or limited political ambition, so are effectively empty promises – there is a 90% chance that we are still on track for 2.4°C of global warming under this best-case scenario, which will lock in centuries of irreversible changes to the climate system.
I know these numbers are hard for most people to absorb, so perhaps the best way to grasp the reality of climate change in Australia is to consider the impacts we’ve already witnessed so far with 1.2°C of global warming.
Australia’s vulnerability to climate change
As the driest inhabited continent on the planet, Australia is particularly vulnerable to climate change. Our nation is a huge island surrounded by the Pacific, Indian and Southern oceans, resulting in dramatic swings in our weather. You can think of Australia’s background climate as essentially a tug of war between warm tropical influences from the north and cool temperate systems from the south.
The weather experienced from season to season is driven by differences between the rate of warming of the hot land and surrounding cool ocean. These contrasting temperature and air pressure gradients set the scene for the complex interaction of atmospheric and ocean cycles that drive Australia’s highly variable climate.
These factors make weather and climate forecasting very difficult in our part of the world – there are a lot of complicated dynamic processes that are hard to represent with the mathematical equations used to drive climate models. It’s a bit like trying to reduce the functioning of each part of the human body down to lines of computer code. It’s very, very difficult – if not impossible – to capture the full complexity of behaviour.
This is especially true in a rapidly warming climate which is now altering historical weather patterns, making them more erratic and harder to predict. Nonetheless, there is still a huge amount we can say about the operation of the Earth’s climate, with advances in computing technology and our fundamental understanding of the science rapidly improving our models with every passing year.
To add to the complexity, the landmass of Australia stretches from the tropics in places like Far North Queensland to the temperate mid-latitudes of Tasmania, generating an enormous range of climate zones that sustain rainforests, coral reefs, deserts and alpine environments. This is why we can have tropical cyclone conditions, extreme heatwaves and bushfires happening at the same time across the country, challenging emergency services.
Australia is also the flattest continent on Earth, meaning that weather systems can travel vast distances without being tripped up by rugged terrain, unleashing destruction over large areas. The mountain chain that moderates the weather and climate of Australia’s east coast is the Great Dividing Range, a feature that stretches 3,500 kilometres from the northern tip of Queensland, running the entire length of the east coast before disappearing into the central plains of western Victoria.
When weather systems collide with mountains, there can be rapid uplift of air masses, leading to atmospheric instability that can result in severe thunderstorms and torrential downpours that trigger flash flooding and destructive winds. But essentially, away from the eastern seaboard, Australia is mostly a flat, dry desert with wet coastal fringes that house our capital cities. Today, close to 90% of Australia’s population lives within 50 kilometres of the coast, and that number is increasing, leaving us particularly exposed to the threat of sea level rise.
When thinking about the effects of a warming planet, it is important to understand that the world does not heat up uniformly. Because of the presence of oceans, mountains, glaciers and forests, different areas of the Earth warm at different rates. The geographical characteristics of Australia mean that the continent is warming faster than the global average – temperatures have risen by 1.5°C since 1910, compared with the 1.2°C global increase since pre-industrial times.
Given that around three-quarters of Australia is already classified as arid or semi-arid – with half of the country receiving less than 300 millimetres of rainfall each year – further warming threatens to make life on an already very dry continent even harder. We are very vulnerable to intense swings in rainfall that cause droughts and floods, relentless heat, and the risk of permanent inundation of low-lying areas from rising seas.
As global warming continues, Australia’s climate is fast becoming more extreme and unpredictable, edging us closer towards breaching thresholds that will make it very difficult, if not impossible, to adapt to. This is especially the case when there are simultaneous disasters unfolding in different regions, or a rapid succession of back-to-back disasters that undermine the ability of communities to recover. If there is not enough time between destructive events, the damage begins to compound. We see the continued degradation of our natural environment and the weakening of social resilience that will eventually lead to the permanent displacement of people from their homes and ongoing impacts on our economy.
We don’t need to use our imagination to picture what this scenario looks like. The Black Summer bushfires of 2019–20 and the 2022 east coast floods highlighted Australia’s lack of preparedness. Our emergency services were alarmingly under-resourced and stretched thin across vast areas, which left many local communities to fend for themselves.
During the catastrophic flooding of the town of Lismore, in northern New South Wales, in 2022, we witnessed extraordinary scenes of locals rescuing each other from rooftops in their boats, jet skis and kayaks when the handful of State Emergency Service crews were overwhelmed by the needs of 45,000 residents. People in rural areas set off in their boats with cordless angle grinders to cut people out of the roof cavities of their homes where they’d been forced to retreat. The situation was so bad that the army had to be called in, but it did not show up until a full five days later, leaving the terrified community feeling abandoned.
Over two years on, people from Lismore are still displaced from their homes and uncertain about how to move forward. Do they plan to relocate the town and pray that another once-in-a-century flood won’t happen again, or is the writing already on the wall and it is time simply to abandon ship?
Climate tipping points
Despite our inherent vulnerabilities, Australia still does not have a national climate change adaptation plan, as other parts of the world do. Although the government is in the process of developing a national strategy – essentially, we have a plan to make a plan – the pace of progress has been disastrously slow, given the urgency of the crisis we face.
While all states and territories have adaptation plans of some kind, the lack of national leadership has meant that regions have had to go it alone without adequate operational resources. Without national coordination and funding, these plans are little more than words on a page.
How many disasters does it take to wake people up to the fact that Australia’s climate is becoming more extreme, with today’s destruction set to be dwarfed by things to come? Do people realise that adapting to climate change won’t be possible in some parts of the country? Exactly how much do we need to lose before our political leaders decide to take this seriously?
The scientific reality of a rapidly warming world is very confronting, especially in Australia. As the years since our Black Summer have shown us, the prospect of a future of dealing with back-to-back disasters across the country every year is ultimately going to be impossible for our ecosystems and communities to adapt to.
The conditions experienced in 2023 have many experts worried that we may have breached regional and global tipping points that will unleash a cascade of changes that will be with us for thousands of years. The problem is that we will only know if we have definitively crossed critical thresholds for planetary stability in hindsight, so we have to move forward armed with the best available science while we still can to minimise the damage.
The latest research shows that several tipping points, such as the disintegration of the Greenland and West Antarctic ice sheets, may be triggered within the Paris Agreement range of 1.5°C to 2°C of global warming. This means it is possible that the Earth will experience major transformations even if we manage to achieve the goals of the Paris Agreement.
In a 2024 report released by the CSIRO on the risks of tipping points to Australia, the authors warn:
The effects of tipping points on the global climate are generally not currently accounted for in projections based on climate models. This means that effects of tipping points are also not included in national climate projections and impact assessments for Australia and may represent significant risks on top of the changes that are generally included.
The report suggests the need to plan for “low likelihood high impact” scenarios that include climate tipping points. For example, the construction of new critical infrastructure should incorporate global sea-level rise scenarios of around two metres by 2100. Given that we are a highly coastal nation, the adaption challenge of planned relocation and retreat will be enormous.
While it may be possible to protect vulnerable areas with sea walls or the restoration of natural dunes for a while, these are only band-aid solutions that will not stem the rising tide for long. Hard decisions will need to be made by local councils around the country about how and when they plan to withdraw residents from high-risk areas. As the Australian Academy of Science notes: “Under high levels of warming and sea level rise, retreat is likely to be the only feasible long-term strategy.”
Scientists know the situation is very bad, but we also know exactly what we need to do to stabilise the Earth’s temperature and avoid triggering a domino effect of impacts in other components of the climate system. If we don’t put the brakes on industrial emissions immediately, children alive today will inherit this nightmarish future.
It makes me wonder if people in decades to come will look back at the world’s collective failure to shut down the fossil fuel industry in time and see it for what it really is: an intergenerational crime against humanity.
This is an edited extract from Highway to Hell: Climate Change and Australia’s Future (Black Inc.)
by Joëlle Gergis, Honorary Climate Research Fellow, School of Geography, Earth and Atmospheric Sciences, The University of Melbourne
This article is republished from The Conversation under a Creative Commons license. Read the original article.