By Nicholas D’Alonzo
The Intergovernmental Panel on Climate Change (IPCC) recently released a new report on the impacts of, adaptation to, and vulnerability to climate change – and it is a difficult report to read, for multiple reasons. Despite the authors’ best efforts to make it accessible, this is still a highly technical report which contains a lot of jargon and terminology that can be difficult to understand. It is also difficult to read because of the grim future it predicts.
It is a long report, 3,676 pages, so I couldn’t possibly summarise it all for you, but what I can do is try to give you the tools for you to be able to read it yourself. The goal of the report is to convert known climate hazards from a warming world into more tangible effects on the human and natural world.
Climate risk is split into three components: hazards, exposure and vulnerability. Hazards are the climate changes themselves; exposure is how exposed to these changes is a given population; vulnerability is how well that population is capable of adapting to those changes. When these factors are combined, we get climate risk for a given population, both human and non-human.
Predicting the future is hard
In order to attempt to predict the impacts of climate change and how human societies might react to it, the IPCC models what it calls Shared Socioeconomic Pathways (SSPs).
SSP1 is a scenario where climate justice is achieved, where developed nations help developing countries to adapt to climate change.
SSP2 is where global inequality continues as is; while in SSP3 there is resurgence of nationalism and a lack of co-operation.
SSP4 is an acceleration of inequality as developed countries move forward with beneficial technology, but that technology is then only attainable for the rich both globally and within a country.
SSP5 is where every developing country attempts economic growth through fossil fueled expansion in a similar way to how industrialised nations achieved their prosperity.
Last year’s Physical Science Basis IPCC report produced the Representative Concentration Pathways (RCPs) that plot how the future might warm, with their numbers based on the amount of additional watts/m2. RCPs don’t plot a path of how we might get there or how society will react to climate change. However, when RCP and SSP are combined we get a fuller picture of possible futures.
When reading the report, it is important to keep in mind what is the most likely future, and how we, as activists, can move society from one pathway to another.
RCP 4.5 is considered the path we are currently on; we have only just started to reduce emissions in developed countries, and global emissions continue to rise. RCP 4.5 assumes emissions will peak in 2040 and global temperatures will rise by around 3 degrees celsius by 2100.
RCP 3.4 is the path where current climate change agreements are successful and we are able to start reducing worldwide emissions very soon and temperature rises peak at approximately 2.1 degrees celsius by 2100.
RCP 2.6 is a part of increasingly stringent emission reductions, but still represents a failure to prevent warming beyond 1.5oC by 2100. RCP 1.9 is what a pathway to below 1.5oC looks like.
A lot of media outlets look at the most alarming results with RCPs of 8.5, but that is not the most likely scenario; it is between RCP 1.9 and 4.5 and that is alarming enough. Ultimately, I consider SSP2-4.5 as the business as usual scenario, and SSP1-1.9 as the ideal goal.
Projected Climate Change impacts on Australia
The report is large, so I am going to focus on Chapter 11 – Climate impacts on Australasia. The projected impacts are split into near term (2030-2060) and long term (2060-2100). Buckle up, as this is about to get grim.
In the near-term, climate change is expected to be the dominant stress on Australia’s biodiversity, with some ecosystems irreversibly changed; this includes threatened species going extinct.
For Western Australia, the south western jarrah forests are expected to change or collapse due to hotter and drier conditions with more fires. Overall, 47% of Australia’s vegetation is at risk of their climatic tolerances being exceeded due to increases in mean temperature by 2070.
In the ocean, the combinations of marine heat waves and ocean acidification are damaging our delicate coral reefs, with record high coral bleaching events. Even achieving the 1.5oC Paris Agreement target will not stop these bleaching events.
The heat, acidity and sea level rise are projected to result in the continued decline in all coastal ecosystems and fisheries, not just coral reefs. These existential threats to Australia’s biodiversity are not properly being addressed by current conservation strategies.
Bushfires have been a common hazard in Australia and most vegetation is adapted to quickly bounce back from fire. Climate change, however, is increasing the frequency and intensity of fire weather, projected to be 15% more common.
Repeated large fires can overwhelm the vegetation’s ability to regenerate. When it comes to the human costs of fire, the news isn’t much better. Fires between 1987 and 2016 cost $1.1 billion per year on average; the 2019/2020 fires cost somewhere in the order of $8 billion.
With climate change increasing fire hazards and increasing cost of fire suppression, there are serious resource constraints on the ability of Australia to fight fires.
Australian crop yields are projected to decline due to hotter drier conditions. The combination of both heat and drought could lead to even greater losses than drought alone. The additional carbon dioxide (CO2) in the atmosphere may offset these losses, but the crops also have a protein loss of 6%.
Climate change will move the agro-ecological zones, requiring a complete shifting of agro-industries from one region to another. The rural areas of Australia are already struggling with poor infrastructure and ageing populations; climate change will make these disadvantages worse.
As we have seen over the last week, floods are a serious threat to life and property. They are usually the most costly natural disasters, averaging $8.8 billion a year. Extreme rainfall events such as those experienced by Queensland last week are projected to become more intense, but the magnitude of the change is uncertain.
Coastal flooding and storm surges are likely to become more frequent with rising sea levels; sea level rise is projected to be 0.2-0.3 m by 2050 and 0.4-0.7 m by 2090. Former once in 100-year coastal flooding events might occur several times a year. This will seriously damage beaches, coastal properties and tourist infrastructure.
Currently, there is no national plan to deal with the risks of coastal flooding, and coastal development continues unabated.
In Australia, 90% of people live in cities, and urban environments are often much hotter than surrounding areas. This urban heat island effect can greatly increase the risks of heat exposure for those living in lower income areas further from the coast and those who are outdoor workers.
For east coast cities, heatwave related excess deaths are projected to increase by about 300 per year between 2030-2080 for the successful RCP 2.6 scenario. Perth is expected to have 36 days over 35oC by 2030. For comparison, this particularly hot summer (the hottest summer on record for Perth) had 31 days over 35oC.
Climate change presents a serious issue for Australia. Not only for our delicate ecosystems which are already under extreme stress, but also for our agriculture and our coastal way of life.
The changes in the climate exacerbate existing vulnerabilities and impact the most disadvantaged.
The tangible costs in infrastructure repair, insurance, lost tourism etc., while high, are still lower than the intangible costs of mental health, loss of ancestral lands and cultural sites, and the loss of important and beautiful ecosystems.
The world is currently not on the path to keeping global temperatures below 1.5oC and the window for achieving this is closing fast. Beyond 1.5oC, the global climate risks become high and are sure to be extremely damaging.
Most of the alarming numbers I quoted in this section are for an RCP 2.6 scenario, a path we are not yet achieving (we are on a trajectory for 4.5oC) but is still beyond 1.5oC. Climate activism walks a fine line between the necessary urgency of action and despair, from thinking it might not be enough.
Although reading reports like this can feel completely overwhelming, it is critical for us to not lose our fierce determination and stubborn optimism for shifting society towards a better pathway for humanity and our planet, our home.
The antidote to despair is taking action with a community of like-minded people. If you aren’t already a part of the climate movement here in Boorloo (Perth), we encourage you to connect with us and take action for climate justice and the future we want to see.