Climate change challenges some of the fundamental assumptions on which our cities have been built. Within a generation or two, a city like Sydney may become exposed to a climate that is more similar to that of Brisbane, while Brisbane may have to get ready for conditions currently more at home in Far North Queensland.
In no way should this challenge be underestimated by our city leaders and decision-makers.
Cities are highly adaptable systems. They are complex in political and economic structure and in social fabric, but these intricacies also harbour a huge creative potential that makes them centres of innovation.
In Australia, cities have managed to absorb, to different degrees of success, rapidly growing populations, increasing demand on public facilities and infrastructure, changing mobility patterns and significant technological innovations.
They now have a new, huge challenge ahead of themselves: to accommodate significant climatic change while maintaining their liveability and functioning as an urban system.
What are the risks?
Cities are characterised by higher density and conglomerations of built infrastructure and people. The combination of these poses a unique set of risks.
Climate change will challenge the business-as-usual activities of urban centres in different ways.
More frequent and more intense extreme weather events such as storms, heavy rain, flooding and heatwaves are among the most concerning effects of climate change in the short run.
All our major cities are coastal: as a matter of national interest, decision-makers need to take the long-term effects of rising sea levels into account. Recent assessments of the expected impacts of sea level rise on coastal areas have been a step in that direction.
Even in the medium term, coastal towns will see increasing effects of sea level rise on their foreshores and coastal properties. Changing erosion and inundation patterns during storm surges, king tides and heavy rain are already affecting some areas. In tropical and sub-tropical areas, these risk will be exacerbated by cyclones.
Cities that include flood risk in their spatial planning will need to revise flood risk thresholds in the context of climate change. Drainage systems may need upgrading to cope with more frequent and more extreme flash flooding.
Heatwaves pose a more complex challenge, in particular when they are overlayed with a trend of increasing average temperatures; this is what projections show for parts of southwestern and southeastern Australia.
During the heatwave in the last week of January 2009, the death rate in Victoria increased by 62% compared to the average.
Heatwaves become a particular problem in our continuously expanding capital cities. The effects of heat in large cities are exacerbated by the urban heat island effect. This is where the centres of a large agglomeration get several degrees warmer than their surrounding rural areas because heat is captured in solid structures such as buildings and roads.
In Melbourne, the 2009 heatwave led to the failure of electricity infrastructure and to the buckling of railway lines.
How prepared are cities?
For well over a century, Australian cities have developed systems for responding to a range of climate-related hazards. Response mechanisms exist in all states, usually shared between metropolitan fire brigades, state emergency services and medical emergency services.
Over the past 50 years, mechanisms for responding to emergencies when they arose have evolved into a comprehensive process of emergency management. Significant efforts now focus on preventing extreme weather events from having severe negative impacts and getting people, infrastructure and buildings prepared for natural hazards.
Recent flood events in Victoria and Queensland have yet again brought home how important it is for residents to be prepared rather than merely reacting once a natural disaster unfolds. Our cities have been at the forefront of driving these developments.
Climate change, however, places even greater emphasis on prevention and preparedness. Some of the impacts, such as prolonged and more intense heatwaves, will be new situations for the rapidly growing number of city dwellers from all parts of the world. People won’t be able to rely on their past experiences in assessing the risks involved.
This became apparent in the 2009 Black Saturday heatwave and bush fires. Many people simply did not have a mental reference point to give them intuitive guidance on when the critical threshold had come for leaving fire-prone areas.
The task ahead
Cities have important tasks ahead of themselves to make sure they can withstand the impacts of climate change.
They need to review their land use planning to accommodate for rising sea levels, increasing flood levels and more frequent extreme weather events that affect the built environment.
Planners and decision-makers will have to make a consolidated effort so we don’t get locked in to particular urban development pathways that make city infrastructure, people and environments more vulnerable to the effects of climate change.
We will have to make planning and development decisions now that take maximum future climate change into account. Climate change information and socio-economic projections into the future remain uncertain, but we can’t let that stop us.
Along with these efforts, local governments need to ramp up their public engagement and start conversations now with their residents and business owners. They need to discuss changing climate-related risks and the way these risks may affect particular geographic areas, groups of people, and business sectors.
This will need to include “bottom-up” learning where local knowledge and risk perceptions are taken into account in city-level decision making. Innovative tools such as scenario planning can be useful in this regard.
What we need is a renewed effort in strategic urban planning in order to deal with climate change impacts in an effective manner. Different levels of government need to work together on all aspects of strategic urban planning, including urban growth and expansion, private and public transport, public health and energy and water services.
However, climate change does not take place in isolation. Changing climate and extreme weather events need to be considered alongside social, economic and other drivers of urban change. As we have seen in the debate on densification of our capital cities, the decisions we take now can determine our “development pathways” for decades.
This inertia in the planning and decision-making system leaves us with no sensible choice other than taking end-of-century scenarios of climate change into account in our present-day decision-making on the design and planning of our cities.
Off to a good start, but a long way to go
The good news is that many local councils have begun to assess and plan for the impacts of climate change. This is despite a lack of clarity about how the responsibilities for climate change adaptation will be distributed across different levels of government.
Some councils have shown leadership driven by concerns about changes to their liveability. Some have been encouraged by financial incentives from higher levels of government. Others are mainly concerned about their legal liabilities and duty of care obligations in the face of climate change.
An increasing number of councils have conducted assessments of climate change risks likely to affect their municipality. They have used the assessment results to developed organisation-wide strategies and action plans for responding to the impacts of climate change.
They have come to terms with the fact that some decisions will need to be made now, despite the uncertainty surrounding climate change projections and the political environment at Federal level.
These leading cities need to be commended for taking such action in a national policy environment that can at best be described as polarised on climate change. And they are being recognised as leaders on climate change adaptation, both nationally and internationally.
Seeing the Lake Macquarie City Council and the City of Melbourne as winners in the organisational category of the National Climate Change Research Facility’s Adaptation Champions is just one of many examples that can encourage other cities to follow suit.
Financial and capacity constraints, however, are still placing large hurdles in the way of implementing these plans, even for the wealthiest of cities.
For smaller regional centres, climate change adaptation planning remains out of reach, and the small number of funding schemes available for such activities are insufficient.
They also don’t help those councils that have structural revenue problems and therefore are finding it difficult to supplement external financial support with own funds, human capacity and skills.
Consolidated investment and knowledge exchange between local government officials, community members, and researchers is needed now to help prepare our cities for a changing future.
It is a future that will expose them to a climate they were not designed and built for.