Ellen Phiddian
Cosmos science journalist
The Intergovernmental Panel on Climate Change (IPCC) is responsible for the most comprehensive body of scientific information on climate change.
In the next part of its Sixth Assessment Report, released today, the IPCC has examined the world population’s vulnerability to climate change, and what must be done to adapt to current and future changes.
It’s the second of three sections of this report (Working group II) – Working Group I’s section, released last August, demonstrates that anthropogenic climate change is continuing, while Working Group III’s component, on mitigation, will be released in April. An overall report is coming in September.
The IPCC reports represent a phenomenal amount of work from hundreds of researchers and government officials. It synthesises information from over 10,000 studies, with over 62,000 comments from expert peer reviewers.
Literally every sentence of the summary for policymakers has been agreed upon by consensus from a group of experts and government delegations – the line-by-line approval process alone takes a fortnight. The report in its entirety is a product of several years.
Given the time and expertise involved in making the report, its conclusions aren’t revelatory: the world is becoming increasingly vulnerable to the effects of climate change, poorest people are often the most at risk, and adaptation to these effects will force changes in our lifestyle, infrastructure, economy and agriculture.
While adaptation is necessary, it’s also insufficient. “It’s increasingly clear that the pace of adaptation across the globe is not enough to keep up with climate change,” says Professor Mark Howden, Working Group II’s vice-chair and director of the Institute for Climate, Energy & Disaster Solutions at the Australian National University.
Under the IPCC’s projected emissions scenarios, the climate could warm much more or slightly more, based on the volume of greenhouse gas released into the atmosphere.
“Depending on which of those trajectories we go on, our adaptation options differ,” says Howden.
On our current, business-as-usual trajectory, we can’t avoid the crisis, no matter how much we change our human systems to prepare for or recover from the ravages of climate change.
“Climate adaptation, risk management, by itself is not enough,” says Howden.
The report comes at a pertinent time for Australia, as southern Queensland and northern New South Wales experience dramatic flooding from high, La Niña-related rainfall.
“One of the clear projections is an increase in the intensity of heavy rainfall events,” says Professor Brendan Mackey, director of National Climate Change Adaptation Research Facility at Griffith University, and a lead author on the Australasian chapter of the report.
Mackey also notes that he has extended family members in Lismore, NSW, who today needed to be rescued from their rooftops as the town floods.
Howden says that while it’s hard to link individual disasters to climate change as they occur, he agrees that there are more floods projected for northern Australia.
“I think we can say that climate change is already embedded in this event,” adds Howden.
“These events are driven by, particularly, ocean temperatures, and we know very well that those have gone up due to climate change due to human influence.”
He points out that flooding is a common side effect of a La Niña event, of which more are expected as the climate warms.
Flooding is not the only extreme weather event that can be linked to climate change.
“We’ve observed further warming and sea level rise, we’ve observed more flood days and heat waves, we’ve observed less snow,” says Mackey.
“Interestingly, [we’ve observed] more rainfall in the north, less winter rainfall in the southwest and southeast, and more extreme fire weather days in the south and east.”
All of these trends are expected to continue, especially under high-emissions scenarios.
For Australians, the predictions the IPCC has made with very high or high confidence include: both a decline in agricultural production and increase in extreme fire weather across the south of the continent; a nation-wide increase in heat-related mortality; increased stress on cities, infrastructure and supply chains from natural disasters; and inundation of low-lying coastal communities from sea level rise.
There’s also high confidence that lower snowfall will reduce alpine biodiversity. Forest ecosystems (alpine ash, snow-gum woodland, pencil pine and northern jarrah) in southern Australia will transition or collapse, and heatwaves and sea level rise will damage other land ecosystems. Marine heatwaves are expected to damage or destroy coral reefs and kelp forests, again with high or very high confidence.
The final high-confidence prediction is that Australian institutions and governments aren’t currently able to manage these risks.
“Climate change impacts are becoming more complex and difficult to manage,” says Professor Lauren Rickards, director of the Urban Futures Enabling Capability Platform at RMIT, also a lead author on the Australasian chapter.
“Not only are climatic hazards becoming more severe – including, sometimes, nonlinear effects such as, for example, tipping over flood levees that have historically been sufficient – but also those climatic hazards are intersecting in very, very complex ways. And in turn, the flow-on effects on the ground are interacting, causing what’s called cascading and compounding impacts.”
She adds that many local and state governments and the private sector have both recognised the importance of changing their practices to prepare for or react to climate extremes.
“We have these systems, these infrastructural systems – energy, transport, water, communications, for example – and it’s the need to adapt those at the base of a lot of the adaptation that’s needed,” says Rickards.
Australia is missing a large investment in research on how different places and systems can adapt to the changing climate.
“We’ve seen a really significant reduction in the research into what actions different individuals, communities, sectors, can take,” says Howden.
“And what that means is we don’t have the portfolio of options available for people in a way that is easily communicable, and easily understood, and easily adopted.”
Without this research, as well as work from local and Indigenous experts, some adaptations can even risk worsening the impacts of climate change.
“The evidence that we’ve looked at shows really clearly that adaptation strategies, when they build on Indigenous and local knowledge and integrate science, that’s when they are most successful,” says Dr Johanna Nalau, leader of the Adaptation Science Research Theme at Cities Research Institute, Griffith University.
While the risks Australia faces are dramatic, things are much worse for other parts of the world. Nalau, who was a lead author on the report’s chapter on small islands, says that “most of the communities and countries are constrained in what they can do in terms of adaptation”.
In April, we will have access to the IPCC’s dossier on mitigating climate change and emissions reduction. But in the meantime, Working Group II’s battalion of researchers advocate for better planning for climate disaster, more research into ways human systems can adapt, sustainable and just development worldwide, and rapid emissions reduction.
“Adaptation can’t be divorced from mitigation, conceptually or in practice,” says Rickards.
“We need adaptation to enable effective mitigation. We need effective mitigation to enable adaptation to give it a chance of succeeding. At present, we’re not on track and we need to pivot quickly.”