Both the ruling centre-left Labor Party and the opposition, a semi-permanent coalition of the centre-right Liberal and National parties, won 72 seats - four short of an overall majority.
The result, Australia's first hung parliament since 1940, was a disaster for Labor, which lost 11 seats when voters delivered a 5.4% swing against it - just three years after the party had won the 2007 election in a landslide.
Key to that victory was the Labor Party's rejections of 12 years of the outgoing right-wing government's scepticism towards global warming. Indeed, the 2007 poll was dubbed the world's first climate change election, with Labor leader Kevin Rudd campaigning on a platform to tackle what he said was the country's greatest moral challenge.
Three years later Rudd was ousted by his deputy, Julia Gillard, after his popularity plummeted - in part due to a failure to drive through his flagship carbon pricing policy. Just weeks before calling the election, Gillard took the premiership.
But rather than promising to put the party's climate change policy - the Carbon Pollution Reduction Scheme, which included a modest emissions trading scheme - back onto the legislative programme, she promised a citizens' assembly that would work towards building a consensus on carbon pricing. The idea was much ridiculed in the subsequent election campaign.
In contrast, Tony Abbott, the leader of the coalition and long a climate change denier, had come round to a pragmatic acceptance of the reality of climate change but campaigned on a promise to use grants, rather than a carbon price, to lower carbon emissions.
For an electorate that had overwhelmingly voted for action on climate change just three years earlier, the choice between equivocation on one hand and inaction on the other led to a lack of enthusiasm for either party, says John Connor, chief executive of think tank The Climate Institute. "One of the best outcomes of the election was that neither of them got a mandate for what really weren't credible plans on pollution and climate," says Connor.