The world’s population could reach almost 10 billion by 2050. Most people will live in cities.

To accommodate an additional 3 billion people, we’ll need to build the equivalent of one new city, that can support one million people, every five days between now and 2050.

Currently cities consume 78% of the world’s energy and produce more than 60% of all carbon. Cities are major contributors to climate change, but they’re also highly vulnerable to the risks, especially those on the coast.

Recent research by the ESRC Centre for Climate Change Economics and Policy at the University of Leeds and London School of Economics and Political Science found that cities could help cut global energy-related emissions by 34% at absolutely no net cost.

Cities could reduce their emissions through developments such as energy efficient appliances and fuel efficient transport. These developments have a payback period of just five years, after which the city would continue to see benefits at no extra cost.

So, how can we cut carbon emissions in cities, and make them more resilient to climate change?

Australian cities at risk

Cities may face the threat of sea level rise, more frequent extreme events such as heat waves, and the increased risk of bushfire. This has major implications for the location of new urban development, growth corridors and critical national infrastructure, particularly on the coast.

Over 90% of Australia’s population now live in urban areas and over 85% live on the coast. We’re a highly urbanised nation largely living near the water.

If you overlay where people live now, with areas that are predicted to be at risk from climate change, you can identify at-risk “hot spots”.

The Gold Coast is a good example. Here, a high-density, ageing population lives right on the coast. This leaves these communities open to the combined future risks of sea level rise, increased coastal storm activity and coastal erosion.

The very real challenge now is to plan, design and construct cities that will minimise harmful emissions — and risks to future communities — but still keep them liveable.

Falling behind

Responding to this challenge will require a response from all levels of government and the corporate sector, including financial institutions.

Unfortunately, at the national level in Australia there has been active disengagement from climate change mitigation in our cities. The Major Cities Unit, which provided advice to the federal government on developing Australia’s 18 biggest cities, was abolished.

The Federal Government has also withdrawn investment in public transport, caused uncertainty on renewable energy targets and abolished the price on carbon pollution. We also have no national strategy for adapting to climate change.

Last week, the Federal Government slashed funding to the United Nations Environment Program by more than 80%. This is another nail in the coffin for any progressive, united action on sustainable development in Australia.

In contrast, the European Commission has adopted an EU climate change adaptation strategy. They are now working directly with cities, and even provide positive financial incentives for developing climate change adaptation plans.

The recent US-China joint initiative on climate change importantly included launching the Climate Smart Low Carbon Cities Initiative providing a clear indication by global leaders of the important role and contribution of cities to solving the challenge of climate change.

Some states take the lead

At the state level however, there has been some leadership on decarbonising cities.

South Australia and the ACT are leading the way on the use of renewable energy. The ACT is on track to achieve its 90% renewable target by 2020. They are also the recipient of the 2014 Gold Banksia award for developing a reverse solar auction process that is proving to be a significant attractor for investment in large scale solar in the ACT.

South Australia’s climate change adaptation strategy focuses on water, natural resource management and importantly recognises the need to work in partnership with the City of Adelaide.

At a more local level, there are also glimpses of hope. Melbourne, Adelaide and Sydney are acting on climate change through local government strategies.

The City of Melbourne is pioneering programs such as the cool roofs program and the urban forestry initiative. These are part of a suite of strategies designed to “cool” the central city targeting “heat islands” in future heatwaves.

In Sydney there is a strong emphasis by local government on active transport, including walking and cycling.

Adelaide is working on smart-green buildings and infrastructure, and to minimise the exposure of vulnerable groups to heat waves – the elderly, young children and those with existing health issues.

However, evidence shows that local action without support from the higher levels of government is very difficult. A good example comes with Victoria’s east west link road proposal or more investment in pubic transport. The role of the federal government in funding urban transport is playing a significant role in influencing the outcome for Melbourne’s transport network.

The private sector role

The corporate and financial sector will also be crucial for decarbonising cities. In fact, the private sector could be well ahead of the government here.

Westpac’s climate change plan for 2014-2017 highlights three directions: building resilience, sustainable cities and investing for a 2C economy (an economy aiming to keep warming below 2C). This strategy could well be the basis for a national agenda on cities and sustainability.

Recent action by the Australian National University on divestment signals broader corporate sector change towards a low carbon future.

Earlier this year in a report to the UN Secretary General, the UN Secretary General’s Special Envoy for Cities and Climate Change – in partnership with the C40 Cities Climate Leadership Group – identified some key strategies cities could use to combat climate change.

These included:

Deep building energy efficiency standards for new urban buildings

Building energy retrofits for existing urban buildings

Aggressive energy performance standards for urban building lighting and appliances; and

Mode shift and transit efficiency for urban residents (i.e. planning for compact urban communities that support greater public transport)

Similarly, the UN Sustainable Development Solutions Network is developing pathways for “deep decarbonisation by 2050,” including for cities. This process feeds into the United Nations Development Goals 2015.

These include proposals to “make cities and human settlements inclusive, safe, resilient and sustainable”.

As US President Obama stated on his recent visit to Australia: no nation is immune to the effects of climate change, and every nation has a responsibility to do its part to mitigate it.

Now is the time for Australia to embed climate change risk into planning at all levels of government, especially given the scale of urban development needed by mid-century. This will require strong connections between climate scientists and planners.

In a tight budget context, the savings in adaptation could more than pay in the long term for the transformation to a low carbon and resilient urban future.

This article was based on a talk presented at the Cities in Future Earth Conference hosted by the Australian Academy of Science. Watch Barbara Norma’s presentation here.