Impactful climate adaptation goes beyond projections

While climate risk management often focuses on predictions and data, one climate and water expert is advocating for a shift to outcomes-based planning, embracing variability and real-world scenarios to enable targeted, resource-conscious strategies. 

Recently presenting a webinar on understanding climate projections data and how to apply it in decision making, Ricardo Associate Director Matthew Coulton highlighted the importance of focusing on understanding what we can do to build resilience to climate variability and change, rather than pouring resources into trying to predict the unpredictable.  

"A common approach to climate adaptation planning in Australia has been trying to predict the future, thinking that once we can see the future, we will know what to do about it. But there is deep uncertainty about changes to rainfall in most parts of Australia and we run the risk of pursuing false precision at the expense of meaningful action,” he said.  

“We see organisations confronted with climate uncertainty stuck in decision paralysis, unable to effectively propose and evaluate interventions in the face of many plausible futures. 

"When addressing climate risk, we need to start basic – what are our desired outcomes, what do we already know about the climate-related risks to achieving those outcomes and what options do we have in our toolbox?  

“It is only at this point do we need to engage in detailed analysis of climate data to evaluate the costs and benefits of those options.” 

This can save organisations years of time and millions of dollars. In many cases, there are few options to evaluate and some may represent no-regrets interventions that will deliver improved outcomes across all plausible futures. 

Out with the old 

The production chain for climate projections data is full of uncertainty. Additionally, Australia's climate makes it difficult to separate human-driven climate change from natural variability. 

Coulton said there are alternative ways of utilising data aside from the traditional approach to climate scenario development. 

“Climate projections are made using outputs from multiple models, which helps us better understand the range of plausible futures. The common approach is then to take the 10th, 50th and 90th percentile of the range of outputs and call these ‘dry, median and wet’ scenarios,” he said.  

Coulton said the problem with this method is that it masks temporal variability, which is the cause of our biggest climates risks – such as droughts and floods. Knowing about plausible changes to rainfall averages over decades doesn’t help design a water system resilient to the extremes.  

"I’m a big fan of a slightly newer approach to considering this climate data called storylines,” he said.  

"The storyline approach retains that temporal element – we capture the variability as well as the long-term change." 

"Instead of cutting lines through different projections using statistical analysis, we actually select individual climate model outputs to test whether systems and settings deliver tolerable outcomes. If not, we need to change those settings.” 

Variability in focus  

Given it is variability, and changes to variability, that often causes water systems to be stressed or fail, Coulton suggests an approach that leans into identifying variability-related risks and realistic solutions. 

"What we often see is projections of the future as scenarios showing wetter, drier or much drier futures. But I think we can do better in understanding this data for decision-making,” he said.  

“Using climate model outputs we can develop storylines that reflect the known stressors to our systems, but within a future climate regime.  
 
“For example, we might deliberately select a model that shows long droughts, one that shows an increase in extreme wet and dry, and one that shows gradual decline in water availability.” 

Coulton stressed that this selection must be supported by evaluations that demonstrate the skill of the model representing local climate. 

"When considering future climate, we need to look beyond just changes to averages and consider the variability that stresses our systems – the size of floods, the severity and length of droughts, and the time between filling events,” he said.  

Effective risk management  

Coulton suggests four key steps that any organisation can take to assess their climate risk, with the process scalable depending on available resources and size of the decisions being made. 

“Firstly, discuss desired outcomes for your organisation as they relate to climate. For example, water organisations may aim for water availability, quality and socio-economic outcomes. For most public organisations, these are already documented,” he said.  

"Document and prioritise known climate risks to achieving those outcomes. Be specific - for example instead of describing a risk as ‘drought’ you might describe it as ‘below average rainfall and no major filling events over a period three years or longer’. 
 
“Use your organisation’s internal knowledge to identify and prioritise these risks." 

Second, Coulton suggests a high-qualitative review of climate information to assess if these risk profiles are likely to change, relative to historical conditions, and in what direction.  

“For Australia, we generally know southern Australia will be drier on average, intense rainfall events will be more extreme, drought onset will occur quicker, droughts will be more intense and it will take more rain to restart system inflows following a drought,” he said.  

"Third, think about feasible interventions. In Australia, in urban water management demand-side measures are often exhausted, requiring prioritisation of supply-side interventions like desalination, recycling, or capturing more rainfall. Identify what’s realistic before detailed analysis. 

"Finally, use sensitivity analysis or stress testing to evaluate the performance of interventions under plausible futures. For larger organisations, this might include cost-benefit analysis, forming the crux of the business case for your stakeholders. 

“The benefit of doing your detailed analysis at the end of the process is that you might only have a few options worth evaluating. There’s no point investing millions of dollars and years of time trying to forecast the future when there’s only one, two or three practical interventions available.” 

Interested in learning more about understanding and using climate projection data? Check out Ricardo’s webinar series here.