Lets imagine it’s 2020 in a warmer world. The future is not as bleak as we once feared it might be. Global greenhouse emissions peaked five years ago in 2015. The world has weathered the worst point in tackling the climate change problem. Now unprecedented cooperation between nations, rich and poor, continues to reduce greenhouse pollution each year.

The struggle has brought the world together – the United Nations has never been stronger. The amounts of greenhouse gases in the atmosphere have been driven down by a global treaty, started at talks in Bali in 2007 and completed at the end of 2009.

Ironically, this success is partly due to a nation that delayed action for more than a decade. In 2007, Australia badly needed a climate-change makeover. In the eyes of the world, our government had to transform itself from dirty stop-out to visionary leader. We had just elected a new Prime Minister who wanted to make the most of the opportunities offered by this spectacular redemption.

The Bali conference was pivotal because splits were occurring in the global community about whether the new treaty would build upon the rules designed for the Kyoto Protocol. Countries like the US and Japan were pushing for the new treaty to have no legally binding targets and no penalties for inaction.

Scientists and policy experts were warning the world’s governments that such a voluntary approach would not work, because it couldn’t reduce global emissions rapidly enough. Some in the business community were warning that a voluntary approach would crash the thriving global carbon market because a lack of regulation stripped away certainty.

It was in this hothouse atmosphere that the new Prime Minister from Australia addressed the Bali conference in 2007. On the tenth anniversary of the Kyoto Protocol agreement, he announced to the Parties that his nation would finally ratify it. With our population clinging to the coast and dwindling rivers of a vast dry continent, he admitted Australia had a lot to lose without global action.

On the strength of this dramatic turnaround, he went further. The conference was transfixed as he committed his nation to adopt new legally binding reduction targets after 2012. He reminded the world that the architecture of Kyoto – legally binding cuts for developed nations, emissions trading rules, penalties for non-compliance – were agreements by the global community that had been hard fought and already won. They were foundations worth building upon.

The conference was inspired by this fresh perspective and his speech helped to bridge the gaps between Europe and Japan, between the US and China. It triggered a change of heart in the nick of time.

After Bali, the governments of the world got down to business. A new global agreement was designed to foster a new clean energy economy. It rewrote the rulebook on emission reductions so the whole world was moving towards the goal of reducing global emissions by at least 50% by 2050.

At the end of 2009 a new global deal was finalised – a new US President signed up along with all nations of the world. The treaty had reduction targets for developed nations of cutting emissions between 25 to 40% by 2020. These targets for the wealthiest nations proved crucial in driving a period of rapid technological advancement and growth.

The new deal also introduced new anti-pollution laws and standards in China and India that slowed their emissions rapidly, and pooled funds for the poorest nations to ready themselves for the climate change that was already locked in.

That’s why, now in 2020, we have regained our optimism for the future. We realised the only climate change debate that counts is the debate about the future. We avoided the worst of global warming by taking concerted action early enough.

In 2020, people will look back on Australia’s contribution to the Bali talks. If the new Prime Minister sends the right messages next week, Australia’s role in protecting the planet could be crucial.