Adelaide is regarded one of Australia’s most environmentally friendly and sustainable cities. It’s just one of the many reasons it’s been ranked in the top 3 most liveable cities in the world by the 2021 Economist Intelligence Unit’s Global Liveability Index.

Adelaide’s famous parklands are made up of 29 parks, which surround the city centre and are in walking distance to both city campuses. And with free bike hire available from Adelaide City Bikes, it’s an easy and enjoyable city to ride around and explore with well-planned flat streets.

The rivalry between Sydney and Melbourne stretches back through history. So too does the tug-of-war between Queensland and, well, just about all the other states. While these contests haven’t always been friendly, the race to be Australia’s greenest city will see the whole country benefitting.

All of the local governments responsible for Australia’s capital cities have schemes in place (or in progress) to use energy-efficient lighting in council-run locations, as lighting accounts for as much as 40% of local authority emissions – and a large percentage of council electricity bills.

The cities are also all implementing retrofits of council-owned buildings, and greening public transport (for example, Perth is currently trialling a driverless bus). And all capital cities except Brisbane and Darwin have signed up to the Compact of Mayors, a global coalition of mayors pledging to reduce greenhouse gas emissions.

But some cities are taking it to the next level, challenging themselves to meet some very ambitious targets.

Back in 2002, Melbourne released its strategy to become the first zero-net emissions city by 2020. It has already invested $14.8m in replacing street lights with LEDs, in a bid to cut greenhouse gas emissions and save more than $1m a year and it has the largest concentration of green buildings of any Australian capital city, with 138 green star-rated buildings – including library at the dock, which received the first six star green star rating for a public building in 2014 – and it aims to source a quarter of its energy from renewables by 2018.As part of these targets, Lord Mayor Robert Doyle’s city of Melbourne council – a member of 100 Resilient Cities and a certified carbon-neutral organisation – is investigating the practicality of purchasing renewable energy with other governments and institutions, and aims to buy 120-gigawatt hours worth of energy from new utility-scale renewable energy facilities. It has also committed to not directly investing in fossil fuels (pdf).

In Sydney, the city has also been making headlines for its energy efficiency measures. The council (also a 100 Resilient Cities member) officially became the first carbon-neutral council in Australia in 2011 and aims to reduce the greenhouse gas emissions of the whole local government area by 70% by 2030 (based on 2006 levels).

It has introduced a range of initiatives to achieve this: a $7m LED retrofit program, which is saving around $800,000 a year in energy costs while reducing emissions; a $6.9m council-owned building retrofit program, which is saving an estimated $1.1m a year in electricity bills; and the Better Buildings partnership which has reduced buildings emissions by 45% since 2006 and saved $36m in bills.

Now its newly-released Energy Efficiency Master Plan (pdf) aims to reduce carbon emissions by two million tonnes a year by 2030, save more than $600m, and double energy productivity.

Other capital cities are rising to the challenge. Brisbane city council, led by Lord Mayor Graham Quirk, already uses 100% green energy (from solar, wind and waste sources) and says it will become carbon neutral by 2031. Lord Mayor Lisa Scaffidi has pledged to reduce Perth’s emissions by 32% by 2031, (against business-as-usual emissions), while Hobart’s lord mayor, Sue Hickey, intends to reduce emissions by 17% of 2010 levels by 2020. Finally the Australian Capital Territory and Adelaide are both working to achieve carbon neutrality by 2020.

It’s difficult to directly compare capital cities, says Neil Noye, Hobart’s director of city planning: “Each is in a different climatic zone, which affects energy use, and each provides a different suite of services and has a different range of facilities to manage.” Population size also varies greatly across the cities (from 4.8 million in Sydney to just 140,000 in Darwin), budgets differ and planning controls are not the same across all councils.

However, Prof Ken Baldwin, director of the Energy Change Institute at the Australian National University, says: “It doesn’t matter if you’re in Brisbane or Wagga Wagga, energy-efficiency measures are equally applicable in all jurisdictions.”

“If you’re serious about reducing your greenhouse footprint, you should be doing everything you possibly can to achieve that.”